Jump to content

Got a new (to me) 1980 xs400 Special


compCoder
This post is 4613 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

My father in law passed and left me this motorcycle in his will. Its got ~10k miles on it, and needs some work. It runs alright, though I did have to replace the battery as one side of it had caved in a bit and it wasn't holding a charge, i was able to jump start it, but the lights would go out it would then sputter and stop as soon as i removed the cables. Anyways, new battery fixed that problem, but here are my first couple of issues and I did a bit of searching, but am having trouble finding the direct answer.

1. I need a new gas cap gasket, mine is all cracked and very dry, and the bike is stinking up my garage and hallway as it sits in 100+ heat every day, and I think its the gas slowly evaporating and fumes filling the garage. I read on some other posts and found one on bikebandit.com under the 1981 xs400 that fits it, but its $22 which is a little high IMO. I also found these on mikesXS which is more my price range :)

http://www.mikesxs.net/products-34.html#products

I figure its Part #20-0036, and not the one below it, but a validation would be good so I can get the order in.

2. My electric starter does not work very well. Whenever I jump the bike off (with bad battery) it could crank and start he bike fine, but with the new battery, it will turn the engine once or twice then make the familiar clicking sounds that a car starter makes, and I have to kick start it still. I have yet to get the electric starter to fire off of the battery alone, even with new battery, if I hook it up to a car battery, the electric starts it right up. What would be the process of me remedying this situation, where should i start?

I plan on changing the oil/oil filter this weekend, and also looking for some new air filters (don't know condition of old ones, so would rather just fine a replacement) but still need to do some looking at local and online places for them. Sorry if these are newb questions, but not only am I new to this bike but to motorcycling in general. Its been 12 years since I last rode a dirt bike, so I knew the basics, and was able to get it out and going. I want to do a whole engine rebuild/cleaning this winter on it, but keep it as cheap as possible in doing so and only replacing what HAS to be replaced, and maybe some cables as well.

Thanks for any help.

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.
  • Replies 65
  • Created
  • Last Reply

Top Posters In This Topic

My father in law passed and left me this motorcycle in his will. Its got ~10k miles on it, and needs some work. It runs alright, though I did have to replace the battery as one side of it had caved in a bit and it wasn't holding a charge, i was able to jump start it, but the lights would go out it would then sputter and stop as soon as i removed the cables. Anyways, new battery fixed that problem, but here are my first couple of issues and I did a bit of searching, but am having trouble finding the direct answer.

1. I need a new gas cap gasket, mine is all cracked and very dry, and the bike is stinking up my garage and hallway as it sits in 100+ heat every day, and I think its the gas slowly evaporating and fumes filling the garage. I read on some other posts and found one on bikebandit.com under the 1981 xs400 that fits it, but its $22 which is a little high IMO. I also found these on mikesXS which is more my price range :)

http://www.mikesxs.net/products-34.html#products

I figure its Part #20-0036, and not the one below it, but a validation would be good so I can get the order in.

2. My electric starter does not work very well. Whenever I jump the bike off (with bad battery) it could crank and start he bike fine, but with the new battery, it will turn the engine once or twice then make the familiar clicking sounds that a car starter makes, and I have to kick start it still. I have yet to get the electric starter to fire off of the battery alone, even with new battery, if I hook it up to a car battery, the electric starts it right up. What would be the process of me remedying this situation, where should i start?

I plan on changing the oil/oil filter this weekend, and also looking for some new air filters (don't know condition of old ones, so would rather just fine a replacement) but still need to do some looking at local and online places for them. Sorry if these are newb questions, but not only am I new to this bike but to motorcycling in general. Its been 12 years since I last rode a dirt bike, so I knew the basics, and was able to get it out and going. I want to do a whole engine rebuild/cleaning this winter on it, but keep it as cheap as possible in doing so and only replacing what HAS to be replaced, and maybe some cables as well.

Thanks for any help.

Picked up mine in mid June. Yes, the gas cap gasket listed will fit - I know because I bought one. It is a little pricey!! They are a little unusual in their design. Soak the three screws on the bottom side with some good penetrating oil as they will have to come out for gasket replacement. Another option is to purchase a repro one from MikesXS.com. It is listed there for an XS650 but the gas cap is the same on both bikes. See link below. Much cheaper but can't speak to quality as compared with O.E. version. A couple of other repro rubber parts I have purchased were not as heavy duty as the original.

http://www.mikesxs.net/products-34.html#products

Link to comment
Share on other sites

Picked up mine in mid June. Yes, the gas cap gasket listed will fit - I know because I bought one. It is a little pricey!! They are a little unusual in their design. Soak the three screws on the bottom side with some good penetrating oil as they will have to come out for gasket replacement. Another option is to purchase a repro one from MikesXS.com. It is listed there for an XS650 but the gas cap is the same on both bikes. See link below. Much cheaper but can't speak to quality as compared with O.E. version. A couple of other repro rubber parts I have purchased were not as heavy duty as the original.

http://www.mikesxs.net/products-34.html#products

So you bought the one from bikeBandit right? Do you know if its the same one from mikesXS based off picture shown? I would rather buy the 7 dollar one, and I don't want to buy the whole assembly, as mine is fine minus the gasket.

Also, an update. I was working around it today, and the majority of the gassy smell is not coming from the tank at all but the left carb, looks like its leaking out the main 'port' that points to the front, as it was a bit wet there and i wiped with a shop towel and it got it all black and nasty, and sure enough, it was gas. So the smell is definitely from the carb. I have the haynes manual (my father in law was a mechanic, he is the one that got the thing running again after sitting for a good while) so I will look up what needs to be done to get them off, and while I have them off I may as well take them apart, clean them really well, and get them all fixed up. I don't see any reason I need new jets or anything like that, as right now the bike runs good, pulls hard, idles smoothly, and is surprisingly very fast in second and third gear, in just a short distance i can get up to 50 without barely trying...in fact, WOT is a little much for me, as I am still new to riding anything like this. Any links to good rebuild/clean guides are great, like i said, i do have manual, but i would like to soak outside and get it cleaned as well, as the entire engine is dirty and gray on outside and cooling fins.

And any help on my second question is always great too.

Thanks for your response.

Link to comment
Share on other sites

So you bought the one from bikeBandit right? Do you know if its the same one from mikesXS based off picture shown? I would rather buy the 7 dollar one, and I don't want to buy the whole assembly, as mine is fine minus the gasket.

Also, an update. I was working around it today, and the majority of the gassy smell is not coming from the tank at all but the left carb, looks like its leaking out the main 'port' that points to the front, as it was a bit wet there and i wiped with a shop towel and it got it all black and nasty, and sure enough, it was gas. So the smell is definitely from the carb. I have the haynes manual (my father in law was a mechanic, he is the one that got the thing running again after sitting for a good while) so I will look up what needs to be done to get them off, and while I have them off I may as well take them apart, clean them really well, and get them all fixed up. I don't see any reason I need new jets or anything like that, as right now the bike runs good, pulls hard, idles smoothly, and is surprisingly very fast in second and third gear, in just a short distance i can get up to 50 without barely trying...in fact, WOT is a little much for me, as I am still new to riding anything like this. Any links to good rebuild/clean guides are great, like i said, i do have manual, but i would like to soak outside and get it cleaned as well, as the entire engine is dirty and gray on outside and cooling fins.

And any help on my second question is always great too.

Thanks for your response.

Yes, from BikeBandit. Looks like the one from MikesXS will be the same design since both the XS400s and XS650s used the same gas cap. I just can't speak for the quality of the repro one from MikesXS.

When you say"main port that points to the front" do you mean the fitting where the gas hose attaches? If so, this fitting is called a "Banjo" fitting and is held on by the one bolt you see. If your fuel tap is working properly, gas SHOULD NOT drain from the tank when the engine is shut down since the fuel tap is operated (opened) by engine vacuum created when the engine is running. If you pull the hose from this fitting and gas runs out of the hose, your fuel tap is not working properly. Is the gas hose in good condition or is it leaking where it attaches to the banjo fitting? If the hose is good and is tight on the fitting, maybe the banjo fitting is leaking. You could check the tightness of the bolt on the banjo fitting but don't tighten too much or you might damage threads in the carb. You could also remove the banjo fitting to make certain it is in good shape. There should be a washer (gasket) on each side of the fitting. Hopefully, the float valve in the left carb is working and keeping gas from flooding the carb. Might just be one of these simple things.

There are kits available for refreshing your fuel tap, such as the one here: http://www.oldbikebarn.com/Kawasaki-KZ650-1000-Yamaha-XS400-850-Petcock-Rebuild-Kit

My preference is to keep things stock. When you do so, you don't need to change jets and mess around with carb settings, etc. When things are right, these bikes run well and have reasonable power. Many consider them a good "starter" bike to learn on but I have never really wanted a large, big engined bike. My rides are for fun on the back roads in my area - plenty of back roads in West Virginia - and this bike suits my needs just fine. I don't do all day runs or high speed Interstate runs.

Hope this helps.

Link to comment
Share on other sites

Hello,

I purchased the gas cap gasket from MikesXS and it's worked very well, seems well made.

If you've placed a new battery in the bike, and it won't start up, you may need to look into the cables attached to the battery. Occasionally these rot from the inside, and may be causing the smaller battery to not be able to turn the engine over. I don't think the issue lies with the starter motor, based on what you've mentioned.

From your description I cannot tell exactly where the carb is leaking, so I cannot help with that.

If you don't keep your air filter stock, you will have to re-jet the carbs, which is probably more work than you want to get into. However, stock filters are not cheap, and will probably cost you between $70-$80 to replace both.

I've done extensive work on my XS400, and have ordered many parts from MikesXS and Bikebandit...so feel free to contact me about compatibility. You've inherited a good bike, but it may need a bit of TLC to get it running well.

Link to comment
Share on other sites

Hello,

I purchased the gas cap gasket from MikesXS and it's worked very well, seems well made.

If you've placed a new battery in the bike, and it won't start up, you may need to look into the cables attached to the battery. Occasionally these rot from the inside, and may be causing the smaller battery to not be able to turn the engine over. I don't think the issue lies with the starter motor, based on what you've mentioned.

From your description I cannot tell exactly where the carb is leaking, so I cannot help with that.

If you don't keep your air filter stock, you will have to re-jet the carbs, which is probably more work than you want to get into. However, stock filters are not cheap, and will probably cost you between $70-$80 to replace both.

I've done extensive work on my XS400, and have ordered many parts from MikesXS and Bikebandit...so feel free to contact me about compatibility. You've inherited a good bike, but it may need a bit of TLC to get it running well.

johnsnownw,

Thanks for your heads up on the gas cap gasket from MikesXS. I was not trying to knock them just that I hadn't seen one of theirs. I have purchased several things for my bike from MikesXS and have been pleased with most of the products and their service. I had already ordered the gasket from BikeBandit before I found the listing at MikesXS.

compCoder,

These bikes are a little funny when it comes to the battery. If the battery is low, they exhibit symptoms similar to a weak starter motor problem. It can fool you in that the bike will start and run fine with the kick start. A good, fully charged battery eliminates that. Many folks don't understand that these bikes have a charging system which is basically a trickle charging system in that they may put out full volts but not many amps as compared with car alternators. A rundown battery won't get recharged quickly unless you go for an all-day ride - maybe a little exaggerated but you get the idea. You mention "new" battery. Did you just buy it? Did you fully charge it before installing? Was the battery newly purchased by your father-in-law, with not much run time on it but maybe plus or minus a year old? If so, that new battery could be going bad. Batteries don't like to sit around unused for months at a time. They will chemically deteriorate and not be able to hold a depth of charge. By that, I mean the battery may show full voltage when tested but not have enough amps to properly turn over and start your engine.

The air filters are a dilemma with these bikes. I was lucky to have a pair of O.E. filters in good condition. You can find, with a search, info on how others have rebuilt the filters using foam to wrap around the housing.

Do you really think you need a whole engine rebuild on a bike with only 10K miles? If it has been properly serviced and not abused, the engine should be good-to-go for many miles yet.

Link to comment
Share on other sites

@johnsnownw:

Thanks man, I will check the cables and see if that is where the issue is, i can just replace that with any similar cable to, so will be cheap at the local hardware shop.

@ollie:

sorry, I am not good with the 'lingo' but where the carb connects to the engine, the large opening that connects to the black hose, right where it connects on the left one at the bottom there is a bit of wetness there, however, the hose is repaired with RTV, so it may just be that causing the issue, and it running down underside of hose. Also, the engine and entire bike actually run really well as it is, nice and peppy, idles smooth, just a few small things I would like to correct, mainly smell, electric starter, and all around cleanliness. I think it did sit for a decade or more, but my father in law got it for free from a long time friend and he worked on fixing it and getting it going in no time. I don't think i will overhaul the engine, but a good carb dismantling and cleaning can't hurt, i just won't move jets or adjust floats since everything seems to work well. I am going to try to find a shop here in San Antonio with an Ultrasonic cleaner to clean it. Perchance, anyone have a guide to getting JUST the plastic parts needing removal out for cleaning, so I don't have to dismantle every little thing? I read over it in my haynes, and the book is clear on how to do it (though some weird terms i don't knw what they mean here and there), but it is hard to tell whats plastic and what isn't from pics. I may also call the Advance Auto Parts where i found the battery in stock (and only 41, less than some web sites..lol) if they trickle charged it. I know they had to fill it themselves, as it was stored dry, the guy on the phone said they have the battery/acid kit. Anyways, they fixed it up for me for free...

Thanks for the help so far all!!! I am going to wait to order gas cap seal until i get carb off and can find true problem, incase i need some new rubber parts or seals or something and get it all in one order.

Link to comment
Share on other sites

@ollie:

sorry, I am not good with the 'lingo' but where the carb connects to the engine, the large opening that connects to the black hose, right where it connects on the left one at the bottom there is a bit of wetness there, however, the hose is repaired with RTV, so it may just be that causing the issue, and it running down underside of hose. Also, the engine and entire bike actually run really well as it is, nice and peppy, idles smooth, just a few small things I would like to correct, mainly smell, electric starter, and all around cleanliness. I think it did sit for a decade or more, but my father in law got it for free from a long time friend and he worked on fixing it and getting it going in no time. I don't think i will overhaul the engine, but a good carb dismantling and cleaning can't hurt, i just won't move jets or adjust floats since everything seems to work well. I am going to try to find a shop here in San Antonio with an Ultrasonic cleaner to clean it. Perchance, anyone have a guide to getting JUST the plastic parts needing removal out for cleaning, so I don't have to dismantle every little thing? I read over it in my haynes, and the book is clear on how to do it (though some weird terms i don't knw what they mean here and there), but it is hard to tell whats plastic and what isn't from pics. I may also call the Advance Auto Parts where i found the battery in stock (and only 41, less than some web sites..lol) if they trickle charged it. I know they had to fill it themselves, as it was stored dry, the guy on the phone said they have the battery/acid kit. Anyways, they fixed it up for me for free...

Thanks for the help so far all!!! I am going to wait to order gas cap seal until i get carb off and can find true problem, incase i need some new rubber parts or seals or something and get it all in one order.

Sounds like you are describing what is called the intake manifold(s). There are round black rubber (metal under the rubber) parts. The hose which connects to the bottom hose bib on the left manifold is a vacuum hose. The other end connects to the top of the vacuum fuel tap. It is hidden by the gas tank. There should be a clamp on the hose where it attaches to the manifold. That hose and the one from the bottom of the fuel tap to the left carb should both be replaced. Most likely they are original and have hardened which sometimes means they don't seal well. It is not unusual for a little gas to dribble down into the vacuum hose so if the hose is not fitting tightly some of that gas could leak out. Hopefully, the rubber intake manifold is not leaking where it attached to the head.

After adding acid to a dry battery, the battery must be charged. If the battery is a 12 amp hour battery and is charged, say, by a 2 amp float charger, the charger should be left on for 6 hours. You can see how the charging math works. It is best to charge these small batteries with low amp output chargers - such as a 1 or 2 amp float charger. A float charger will shut off the charge when the battery is fully charged so the battery is not overcharged, boiling out the acid and damaging the battery. Your Advance Auto store may or may not have charged the battery fully/properly. The best type of battery to use in cycles and scoots is an AGM sealed/maintenance free battery. These loose their charge much more slowly on standing, are more resistant to vibration damage and can take lower outside temps w/less risk of freeze damage. They are a little more expensive than the standard wet cell battery. Both types take acid but the AGM battery absorbs the acid into a glass mat so it really can't spill out. You can't ship a wet cell battery w/acid in it but you can ship an AGM battery w/the acid in it.

Link to comment
Share on other sites

@johnsnownw:

Thanks man, I will check the cables and see if that is where the issue is, i can just replace that with any similar cable to, so will be cheap at the local hardware shop.

Not a problem. I'm still not entirely sure where the leak you have mentioned is, but I commend OllieB for possibly figuring it out.

I will say this about carb cleaning. You will need to take the majority of the carbs apart, because there are lots of pieces that contain rubber or plastic. For instance, your butterflies have plastic and rubber, your float assembly has a plastic piece under the float needle, the choke has rubber components and their are rubber washers at the end of your mixture/pilot screws. Therefore, you should probably just do a full dismantle as it's nearly impossible to remove all of the plastic and rubber components otherwise.

Because you can't explain the carb/gas issue you are having very well, which is no fault of your own, it would help us tremendously if you could take pictures of what you're talking about, and post them.

Anyway, good luck.

Link to comment
Share on other sites

You guys asked for some pictures so here they are:

rightsidewhole.jpg

leftsidewhole.jpg

As you can see by the faded paint (its on both side panels and on the top of the tank quite a bit), it did spend some time out behind a barn or something, out in the country just wasting away in the burning sun.

Now here is the right side carb, its real dirty up on the front edge, and the 'boot' that connects it to the cylinder head is all cracked and worn, i guess why he put that rtv on it. I guess I will also be replacing these if I can find some when I rebuild carbs...

rightsidecarb.jpg

And now for the problem side. When I looked a bit closer today I noticed that there is a 'second' valve to shut off after the inline fuel filter, and also, the hose seems pinched where it connects into the carb there, but it seems to get fuel just fine, though it does sputter a bit if i hammer on full open throttle from under ~2200 rpms, but from there to ~8800 it pulls hard and fast, i like it, right around 8800 it starts sputtering again. Also, if I hit too low of a gear while going (as i said, im an newbie still, haven't got my license even, taking class in a couple weeks, so i just ride around my neighborhood streets, i digress...) and try to accelerate from under 2000 rpm, i get some popping/backfiring type sounds out of the motor. Anyways, guessing a petcock rebuild kit will be in order as well...Also, the area i circled in red is where the leaking is, right from where it connects into the cylinder head again, the front of the carb between head and itself is moist under that connection.

leftsidefuel.jpg

And I know I have asked a hella lot of questions here, and thanks for all your kindness in helping me with everything, but like any newbie, I have one more. I was looking in my tank today with a flashlight, and there is a nice thing layer of sludge on everything in there (can still see metal through it) and also some rust around the bung that I can see, and I'm guessing on the top where I can't, what is everyones opinions on Kreem type tank sealing kit? I found the set at my local bike shop today for $49 and am thinking about going ahead and doing it. I have also read that some do cleaning on their own, and just use the POR15 on the inside...better/worse? So much conflicting info out there...some say the kreem is great and lasts a long time trouble free, while others say it peels and eventually clogs the carbs and other problems...

So so far, my list of things needed are:

Petcock rebuild kit (i would guess due to extra valve, going to test this weekend when i remove tank).

2x basic carb rebuild kit (until i take apart and see if I need any inner parts, or if everything is good).

Gas Tank restorer/rust remover of some type

Gas tank lid gasket

Gas lines so when i rebuild petcock i can remove other valve (I'm guessing a basic hardware store may have this for cheaper than online, or even basic auto parts store, i will take a look).

so thats my list of things to do to it so far when I crack into it. I don't think the engine needs a rebuild at all, as it runs great once I get it going, though still having problems with battery, though i rode constant for about an hour today, and when i turned it off, i was able to start it right back up from the button starter. And i was unable to start from kick start, had to jump again, when i turned on key, lights come on, I push button, one or two turns and lights are VERY dim. I will check the battery wiring as well once i get cracking...any other suggestions/tips/help anyone has is very much appreciated, once I find all the parts I may post them on here for verification is the 'right' stuff to get, as far as petcock kit, carb kit, etc.

Link to comment
Share on other sites

I'm glad to see you looked into the gas tank, as I was going to mention that you're inline fuel filter seems to have rust in it. Here is what you need to do:

1. Pull the gas tank off and clean and restore the tank. I did this by using electrolysis and the POR-15 motorcycle kit. If you search the forum you will find a discussion detailing my use of this method.

2. The part that you are describing as leaking is called the carb holder or carb boot. You should replace both carb holders.

3. Dismantle the carbs, as they are probably pretty gummed up, not to mention that there is probably rust from the tank in them, despite the fuel filter.

This should be your main focus, as you probably shouldn't be riding the bike around with these issues anyway.

After completing the above, you can focus on the electrical issues. I would suggest replacing your fuse box, with more up-to-date fuses, but not before checking all your wiring to see if there is an issue. Some have just upgraded their fuse boxes to a newer box that still uses glass fuses. I however replaced all mine with in-line fuse holders that use mini-blade type fuses. Either way check on the electrical system as a whole before attempting the upgrade.

The bike looks pretty good, considering it's been sitting around for some time.

Good Luck.

Link to comment
Share on other sites

1. Pull the gas tank off and clean and restore the tank. I did this by using electrolysis and the POR-15 motorcycle kit. If you search the forum you will find a discussion detailing my use of this method.

--thanks, i will look up your post on this.

2. The part that you are describing as leaking is called the carb holder or carb boot. You should replace both carb holders.

--dang, found some on mikesXS and they are pricey...but what I need is what i need.

3. Dismantle the carbs, as they are probably pretty gummed up, not to mention that there is probably rust from the tank in them, despite the fuel filter.

--this is going to be starting this weekend, hopefully i can find a shop that can ultrasonicly clean them for a good price, I have seen many say its ~ $20 if you bring it in dismantled

After completing the above, you can focus on the electrical issues. I would suggest replacing your fuse box, with more up-to-date fuses, but not before checking all your wiring to see if there is an issue. Some have just upgraded their fuse boxes to a newer box that still uses glass fuses. I however replaced all mine with in-line fuse holders that use mini-blade type fuses. Either way check on the electrical system as a whole before attempting the upgrade.

--There are already inline fuses in the bike, each with some yellow paint marking what they do, like H (guessing headlight), R (rear stuff?), etc. I will have to chase the wire and do some deciphering on them. I will check all wiring and ensure its not too dry/rotting when i get everything apart, if it is, just buy some wire from Lowes or something and rewire what I can...a little anxious about getting in 'over my head' as I don't know much about motorcycles and have never done a carb rebuild (never owned a car with a carb even...showing my age :P )

The bike looks pretty good, considering it's been sitting around for some time.

Good Luck.

--Thanks, I thought it was nice as well. i did polish up all the chrome parts. There is a bit of rusting on the metal part that leaves brake fluid container up top and spots on the handlebars, nothing i'm worried about at this time, but will replace when i get it running reliably so I can drive it to work...after getting my license endorsement of course.

Link to comment
Share on other sites

From the pics, your bike doesn't look all that bad. Same color as mine! Many bikes of this age will be a rust bucket. Cleaning and polishing will do wonders. The exhaust system looks pretty sound - as far as can be seen. Not unusual for the paint to be faded some even if the bike wasn't kept outdoors all the time.

Yes, you should concentrate on removing the carbs, replacing the intake manifolds rubbers, vacuum hose, fuel hose, tank cleaning and fuel tap rebuild.

Also, order a set of ignition wires and caps from MikesXS. If yours are original - and they probably are - they are too old and need replacement. Cheap stuff. New plugs if they weren't recently replaced. Forgot if you mentioned that.

Yep, the RTV was/is used to try to patch bad intake rubbers. Of course, if you disassemble the carbs, you will need new gaskets. My intake rubbers were bought from ebay and are new O.E.M. aftermarket parts of good quality from Japan or Taiwan - I forget which. There is some pretty crappy stuff coming from China.

No, you can't get the fuel tap parts at a hardware store or the like. You need the specific kit for that tap from a place that offers Yamaha parts. With the fuel tap working properly, you can remove that extra shutoff valve. If the in-take (part of fuel tap) gas filter is in good condition, you really don't need the extra in-line filter but some use them anyway - your choice.

The issues you describe may completely disappear after you do the above things. Sounds like it is not running all that bad anyway.

There are a couple of other external carb seals that can leak vacuum that you might replace while doing the work - the o-ring seals on the idle mixture screws accessed from the tops of the carbs and the butterfly shaft seals. On some bikes never modified, there are plugs in the holes over the idle mix screws to keep us peons from changing the too lean factory setting of about 1.5 turns from seated. Most are recommending 2.5-3 turns out from seat. When checking, don't turn the mix screw downward with too much force as you can damage the seat and mix screw. You'll find other posts about that here. The butterfly shaft seals = 2 on each carb. The butterfly shaft seals can be purchased separately from MikesXS (34 mm Mikuni carb). The idle mix o-rings come in a set of o-ring, washer and new blind plug, IIRC. You can probably get just the o-rings from other sources but you do need o-rings that can resist gas/oil damage.

BTW, for this engine, I like regular diesel grade (not synthetic) oil in 15W40 weight. You can buy any name brand - such as Shell, Mobil, Valvoline, etc. Not only is this type oil good for diesel engines but is also specified for hard working older gas engines. I use it in my 1990 and 1977 Mercedes gassers, too. Wix brand oil filters are some of the best and the Wix Co. makes the filters for NAPA. New o-ring gaskets are included with the filter.

Link to comment
Share on other sites

Alright, I am about ready to order some parts (what I can afford for this week). I am going to go for getting the gas tank down to the carbs ready and wait until I take apart carbs to get a full list of parts that I need to rebuild them.

Gas tank restore kit:

http://www.amazon.com/POR-15-Cycle-Tank-Repair-Kit/dp/B000H9K4JQ

Petcock Rebuild kit:

http://www.z1enterprises.com/detail.aspx?ID=305

Carb Holders (go ahead and get these for combined shipping):

http://www.z1enterprises.com/detail.aspx?ID=2635

Gas cap gasket (Part #20-0036):

http://www.mikesxs.net/products-34.html#products

New Fuel line (Part #20-4010, is this the right hose or the smaller stuff??)

http://www.mikesxs.net/products-34.html#products

If I find the fuel filter to be missing from my petcock or the inline on uncleanable, then I will just go and pick up a new one from autozone or something...im sure they are common enough.

So thats what I have for now unless anything else is really 'needed' for doing the tank down to the carbs portion rebuild. I know there may be a nice to have here and there, but I am trying to do this on as little funds as possible...but dont' want to leave out something that needs fixed/replaced either.

Thanks all for the help so far, will take some pictures of how the progress goes next weekend, as I will be ordering Thursday evening, it will all be here by then hopefully...

Link to comment
Share on other sites

Alright, I am about ready to order some parts (what I can afford for this week). I am going to go for getting the gas tank down to the carbs ready and wait until I take apart carbs to get a full list of parts that I need to rebuild them.

Gas tank restore kit:

http://www.amazon.com/POR-15-Cycle-Tank-Repair-Kit/dp/B000H9K4JQ

Petcock Rebuild kit:

http://www.z1enterprises.com/detail.aspx?ID=305

Carb Holders (go ahead and get these for combined shipping):

http://www.z1enterprises.com/detail.aspx?ID=2635

Gas cap gasket (Part #20-0036):

http://www.mikesxs.net/products-34.html#products

New Fuel line (Part #20-4010, is this the right hose or the smaller stuff??)

http://www.mikesxs.net/products-34.html#products

If I find the fuel filter to be missing from my petcock or the inline on uncleanable, then I will just go and pick up a new one from autozone or something...im sure they are common enough.

So thats what I have for now unless anything else is really 'needed' for doing the tank down to the carbs portion rebuild. I know there may be a nice to have here and there, but I am trying to do this on as little funds as possible...but dont' want to leave out something that needs fixed/replaced either.

Thanks all for the help so far, will take some pictures of how the progress goes next weekend, as I will be ordering Thursday evening, it will all be here by then hopefully...

Everything looks good, except for the fuel line, that one is too wide.

Link to comment
Share on other sites

Alright, thanks johnsnow I will ensure I order the smaller hose.

And ollie, i will go ahead and take your advice and order new ignition cables and caps, and I will go ahead and get plugs as well. I am sure my father in law put on new ones, but I may as well make sure, they are cheap enough. So I have a couple questions on what exactly to order (again, just verifying). I read I should get the non-resistor caps, as the weak ignition of the xs400 has a hard time with them, if that is right, I am guessing this is the stuff that I need:

From this page:

http://www.mikesxs.net/products-27.html#products

cables: Part #23-2902 (is the 'performance' wires really worth the extra, doubting it here...)

caps: 2x Part #23-3114

plugs: 2x Part #50-6501 (are the 'iridium' plugs worth the extra here, if so I will spring for them, but 2hp sounds a little iffy out of a small motor and just plugs)

Thanks again guys for all your help, I will post images of everything that I work on. Oh, and one last thing. While I have the bike partially dismantled, I would like to go ahead and clean up the engine a bit, I am guessing I can just douse it in engine degreaser, let soak for a few mins, and hose off, from there, get some simple green and a tooth brush or brass bristle brush and detail whatever is still messy. i would just cover the head intake holes where carb holders go with some duct tape. I plan to put this order in tomorrow evening, so if I don't here feedback I will go with exactly what I listed above, if I do, i may get the more expensive wires and/or plugs if really worth it.

Link to comment
Share on other sites

Not a problem.

I ordered the performance wire simply because I thought my finace would like yellow, they don't seem to be any different other than the color. If you like yellow, get them, if not then I would just get the regular black ones.

Those Iridium plugs seem like a bum deal to me, I haven't bothered with them.

That's just my :twocents:

Link to comment
Share on other sites

Your bike has electronic ignition, not points. Intensity of spark will be ok unless coils are weak. I would go with the stock setup: 5K ohm caps and NGK non-resistor plugs. Original caps were 10 ohm resistance but the 5Ks do just fine. Just my personal opinion but I don't care for Iridium, etc. plugs on these older bikes. Iridium is less conductive and used in plugs mainly to extend service life of modern cars because Iridium electrodes erode at a slower rate. Modern engines produce a much hotter spark and can handle the lower conductivity of Iridium metal. I have used Nology Silver (silver electrode) plugs in them because silver has one of the best conductive rates but they are kinda pricey. Stick with NGKs for your setup. I buy my NGK scoot and cycle plugs at Advance Auto. They might not have them in stock but can get them from the warehouse in a day or two.

Link to comment
Share on other sites

Alright, all my parts have been delivered, though it seems the etch in the tank restoration kit has leaked a bit, probably about 1/8th of the bottle, but i don't think it will be an issue and its not worth paying the return shipping, so I will go with it. Hopefully this weekend I will be removing the tank, starting its process to fix, rebuilding the petcock, and start with the carburetor cleaning. As far as the cleaning goes, should just a couple cans of carb cleaner be good, or do I need a bath of some sort? I can also just boil the parts in a large pot with water/lemon juice or something similar if that is good enough. I am not only having a hard time finding a place with an ultrasonic cleaner that will just clean the disassembled parts for me, I found two places with one, but they require that they do the entire service (which is BS in my opinion, so i would rather them not do it anyways). Should I maybe get a bath of some sort, or will my above plans be ok? Oh, and I went ahead and bought a single clear gas line from Z1 as well that I will use to balance the carbs with the old ATF method...

Thanks again all, can't wait to get this process started and get it running reliably so I can use it for transport...

Link to comment
Share on other sites

Alright, all my parts have been delivered, though it seems the etch in the tank restoration kit has leaked a bit, probably about 1/8th of the bottle, but i don't think it will be an issue and its not worth paying the return shipping, so I will go with it. Hopefully this weekend I will be removing the tank, starting its process to fix, rebuilding the petcock, and start with the carburetor cleaning. As far as the cleaning goes, should just a couple cans of carb cleaner be good, or do I need a bath of some sort? I can also just boil the parts in a large pot with water/lemon juice or something similar if that is good enough. I am not only having a hard time finding a place with an ultrasonic cleaner that will just clean the disassembled parts for me, I found two places with one, but they require that they do the entire service (which is BS in my opinion, so i would rather them not do it anyways). Should I maybe get a bath of some sort, or will my above plans be ok? Oh, and I went ahead and bought a single clear gas line from Z1 as well that I will use to balance the carbs with the old ATF method...

Thanks again all, can't wait to get this process started and get it running reliably so I can use it for transport...

Apparently you can boil the carbs and parts in lemon juice. I haven't done this, but others have. You will probably only need one can of carb cleaner, and use the spray on everything after it comes out of the boil.

I used electrolysis and the tank cleaner, if you plan on just using the cleaner I cannot vouch for the product.

Good Luck.

Link to comment
Share on other sites


  • Who's Online (See full list)

    • There are no registered users currently online
  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...