Ebola Monkey
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Posts posted by Ebola Monkey
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FOR PART # 278-18101-01-00
XS400D 1977
XS400E 1978
XS4002E 1978
XS400F 1979
XS4002F 1979
XS400G 1980
XS400SG 1980
XS400H 1981
XS400SH 1981
XS400SJ 1982
So basically every non seca/maxim xs400 from 77-82. Along with:
R5 - 1970
R5B - 1971
R5C - 1972
RD350 - 1973
RD350A - 1974
RD350B - 1975
RD250 - 1973
RD250A - 1974
RD250B - 1975
RD400C - 1976
RD400D - 1977
RD400E - 1978
XS360_2D - 1977
XS360C - 1976
XS360D - 1977
DS7 - 1972
TD3 - 1972
TR3 - 1972
TZ250 - 1973
TZ350 - 1974
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The current tires are Front: Nankang 3.00-18 Rear Cheng Shin MS90-16 (4.60-16)
From what I can find online Front 3.00-18 is closest to a 90/90. Is this correct?
I haven't found an MS90 on any of the conversion charts. But going by the 4.60 size I'm thinking 120/90. Is this correct?
What are the actual rim sizes for an 82 XS400SJ? With this I can probably figure out what tires are safe for the rim size, and go from there.
Thanks In Advance!
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SOLVED!!
After taking the generator apart last week I decided I would keep the current one instead of replacing it. I had a new resistor cap on order because one was "leaking", and would shock the hell out of me any time I got near it. I also doubled up my battery ground, as I had a spare ground cable. So now 1 ground to the engine, and 1 to the frame right next to the battery.
Charged the battery, and let her rip.
12.3v @ idle
A few revs, and
14.5-14.6V @ >2000rpms
I don't know if the cap helped or not, but I'm guessing the second ground the big fix. I checked for voltage drop on the original cable, and it was good. Maybe there's a crack thats screwing up the ground with engine vibrations, or something. That could help explain the erratic charging. All that matters is that it seems to be working now.
Thanks Again to speedshop, and Drewpy for all your help!
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Not neccesarily.
Regardless of what kind they are - If they're not the exact pipes the buyer wants, then you could lose the sale. I suppose that, at the very least, having completely unmodded OEM pipes at least gives the widest range of options...
Right on.
Aftermarket parts are so readily available, and vary so much they could actually hurt resale. Personally I want to buy a used, unmolested, totally stock bike. Then have my own way with it.
My strategy is this... Put on what I want, but save all the stock parts. That way when I sell it I can either sell it with the stock parts OR put the stock parts back on, and sell the aftermarket parts separately.
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Here they sell the parts, not only the entire drive shaft, :
http://www.cmsnl.com/yamaha-xvs650ananc-2001_model10972/partslist/C-12.html
Perform a search in eBay.Perhaps you find used parts.
Cheers.
Ditto on eBay. You can probably find a used gearbox for next to nothing (comparably).
Might also ask your mechanic if you can source the parts yourself, because they are available separately (cmsnl.com).
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If the new ones are less restrictive you might have to re-jet. That's about the worst. I don't know if the 650's had the same diameter headers, but even if they're different mikes sells the adapters.
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I just went through this with my wifes bike a few weeks ago. We did a basic carb clean, new plugs, etc. We got it to run, but only fired on 1 cylinder. Then it ran OK, then only 1 cylinder again. It was fouling plugs after only about 2 minutes also.
You need Spark/Air/Fuel to run. I'm assuming air is covered.
Do you have spark on that side? Pull the plug, put the wire on it, hold the threads against the case and push the starter button. You should see a spark jumping the gap. If not, try a good plug. If you still don't have spark we'll move on, but I think it's going to be a carb problem since you already mentioned the main jet being clogged.
Also, Drewpy is right. You need to do a thorough carb cleaning before you do anything else, and you need a fuel filter. You'll clog up the carbs over and over again if you don't because you're churning up whatever is in the tank, and you probably already have crap in the carbs.
When we did the basic cleaning we thought it was good, but when I tore into it again I did everything. I found the needle jet was all gummed up with crap. It looked like seaweed in there, and the rest of the carb was nowhere near that bad.
Download This Guide, it's the most thorough guide to your carbs out there. I knew how to clean the carbs, but still learned from it.
Once you have spark, do a good carb cleaning, and add a fuel filter you should be good. You should be able to do a complete tear down, and cleaning in about an hour. Then you know you have a good starting point. Just made sure to put a filter on so you don't get more crap in there, and have to do it again.
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its on the right side and you have to take off the clutch cover!(after draining the oil)
You're absolutely right. I had a brainfart, and was thinking about the one for the clutch .
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There should be screws in there. They are the spots that drewpy pointed out, but if they are untouched they will be plugged with a brass plug. The plugs are pretty thick, and you have to drill a hole in them then use a screw, or something to pull them out. You have to be very careful though because the mixture screws are very close. If you get goofy with the drill you can mess up the mixture screws. If the plugs have been removed the mixture screws are recessed pretty far. Have you actually removed the carbs, and looked?? You can't see the screws without removing them. If you have a flathead screwdriver that will fit in there you should be able to feel them, and adjust. It's a pain in the ass though. They are in the spots with the arrows.
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If there's any question on whether something will work or not, go here http://www.cmsnl.com/yamaha-xs400_model16837/ and compare the different models for carb parts.
They aren't all the same, and when the maxim, and seca came out they were jetted different than the regular XS400's.
I want to say the seca/maxim were jetted richer.
Also, is the Canadian sister site to MikesXS.
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I must admit this is a tricky one. If you are getting the battery voltage at the windings and appearing on the earth side of the regulator thats got to be OK.
11.87 volts from a new battery is very low (13.8 is more like it) , can you get access to another battery? Does the terminal voltage jump up when you disconnect it from the bike's electrics? A car battery slaved in place of the bike battery would do.
Very unscientific, but with the ignition on will the generator just about have enough magnetism to hold a 10mm spanner against the case?
Lets stand back and have a cup of tea (of coffee). The items in the system are: the regulator/rectifier unit. The field windings. The output windings. The wiring. The battery.
The fault lies with one of these! Sherlock Holmes said rule out the impossible, then you must consider the unlikely. If the generator windings bell out OK these must be good. You've inspected the wiring. So really we need to look at the unlikely - the battery and the possibility you have two duff regulator/rectifier units.
I have known good spare XS650 regulator/rectifiers that could be slaved in and would work the same way as the 400 one.
It's SO low at the moment because I had been tinkering around with it so much after I pulled the generator. Now I'm delayed for a few days waiting on the new gasket to come in. I should have the new gasket Monday, at which point I'm going to reinstall the old generator (with some heat shrink around the chafed area), add a second ground strap to the chassis (for good luck), replace the faulty plug cap (assuming it comes in), charge up the battery, and cross my fingers.
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So, i posted earlier about my bike.
Got it running(battery, spark plug.. think it still needs carb work.. but thatll be later)
Anyway, I can get it into first and drive it around the block.. but Im having problems getting to another gear or getting back to nuetral.
After fiddling with it for awhile, i started to realize that the gear selector itself was waaaaaay looser than any other gear selector ive ever dealt with.
Normally, you click down and it snaps back, click up, it snaps back up. etc etc. On this bike.. you snap it down.. it stays down, you snap it up, it stays up. Like waaaay down and way up.
What could be wrong?
Take the left rear cover off (where the shift lever goes through). There's a spring loaded return in there. I would guess that something is broken, or stuck.
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That's what I was getting at speedshop. Trying to bypass regulator to eliminate it as the problem.
Here's what I'm getting with the field coil connected, and ignition on (still disassembled so not grounded via the case right?).
11.87V across battery
11.87V between GREEN from Coil, and Battery negative with the regulator disconnected.
2.50V between GREEN from Coil, and Battery negative with the regulator connected.
11.87V between BLACK from Coil, and Battery negative with the regulator disconnected.(same readings between the ignition, signal, and headlight fuses and battery neg, as they all tie into the same brown wire)
11.07v between BLACK from Coil, and Battery negative with the regulator connected.(same readings between the ignition, signal, and headlight fuses and battery neg, as they all tie into the same brown wire)
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I've been fighting through this charging system problem on my wife's bike, and it's driving me nuts.
I found on some 650 forums that you can bypass the voltage regulator to find out if it's the problem.
Is there a way to do this on the 400's?
I've tried 2 different voltage regulators, 2 different rectifiers, and am ready to try different armatures, and field coils.
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Diodes work or they don't 99.9% of the time.
I found my Haynes book of myths for this bike! Brings back memories! It looks like you are in for an oily mess. The starter drive is in here and the starter motor is sealed as well.
I tore the generator apart today. The cloth wrap on 1 wire from the generator was worn, but the plastic insulation was fine. Other than that, everything looks to be in great shape. There are no visibly damaged areas on the wire sleeve, and nothing looks pinched.
I also cleaned up the other used regulator I have. It has 1 wire worn through the insulation in the same spot, but it's down to the wire, and someone had done a really bad tape job on it. It also has a couple area where the wire sleeving is cracked.
Now, with my meter both armatures OHM out to the exact same numbers (1 - 1.1ohms), and both field coils OHM out to the exact same numbers (3.4ohms). Considering my current wiring is in better shape, should I even bother replacing them?
I destroyed the gasket in the process of getting the armature, and coil out so now I'm waiting until Monday at the very least for that to come in.
I don't know what else to do. I can't start buying "know good" parts for this thing. They're too damn expensive, but with used parts I don't know what I'm getting because everybody says "the bike ran perfectly before were tore it apart". I think we all know that's BS.
Battery - Known good
Stator - Have 2 both test out identical
Field coil - Have 2 both test out identical
Regulator - Have 2 both test out almost identical
Rectifier - have 2 both test out almost identical
It's getting to the point where I want to put it back together and sell it.
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There is a diode under the seat that controls the voltage to your battery if its weak or gone it will not charge!
Diode under the seat is part of the headlight circuit. It's Fresh.
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There's your problem - that field voltage is all over the place. Check the wiring very carefully between the regulator and the generator (i think i read you changed the regulator). I've pointed out that these used to wear through the generator wiring at the gear lever so if you haven't already checked - please do so. My old black SE did exactly this and I saw several other 400s that did the same.
The generator readings are low, they are normally much higher direct off the generator say about 20 volts rising to 50. The meter needs to be on AC. These readings would be low if there was a fault with the field. Which is I think what you are looking at.
You need to see full battery voltage on the field with just the ignition on. For it to drop to 8.8 volts I'd want to be seeing 14.5 or higher across the battery.
Can you confirm you have a solid state regulator and you've tried different ones? If its vibrating contacts, run some 1200 grade through the contacts and re-check.
Its been 20 years since I last owned a 400, can't remember if the generator sits in oil, but there will be a gasket to seal the cover to the engine either way.
I do have a solid state regulator, and have tried another one. I've also recently replaced many of the connectors including the ones to the generator, regulator, and field coil, so I know they are good. I haven't dug in to see where the wires go into the case yet, but that will probably be the next step.
Hopefully someone else remembers if it's going to be filled with oil before I dig in.
Hopefully someone else remembers if I'm in for an oily mess or not.
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no, its on top of the carb as per diagram
Drewpy,
Isn't the mixture screw blocked by a brass cap on the 81? I know it is on the 82.
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OK, here is the problem. The bike (81 XS 400) now starts up no problem, all the lights work properly and for the first few blocks is a pleasure to drive. 3 blocks later I hit a stop light and the thing is now going crazy! The RPM's are at 5,000 and they wont go down! Its the devil!!!!! Does it not want to leave my home? Does this bike hate me?? Where the heck does that petcock lever go? Left, right or the middle? Is it related to the RPM's? What the heck is going on? Also, sometime the bike feels VERY powerful, then the next time I go to ride it seems to be at 70%?? Any suggestions???
Petcock:
PRI: Prime, not vacuum operated, just OPEN
On: Vacuum operated. Only lets fuel through when engine is running, if petcock is good.
RES: Reserve, also vacuum operated, same as above, when you hit the reserve level go get gas.
As far as the revving, check for air leaks in the carb holders. Also what choke setting do you have it on.
Mine I start on full choke, then turn down to half for a few minutes, then off. If I leave it on half it will rev up to around 3000, and stay there after a while.
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can you help me with where to get a carb rebuild kit for the mikuni bs34 carbs, I've been looking and can't find a rebuild kit anywhere, I did find a place that does full rebuilds http://www.wgcarbs.com/index.php?option=com_content&task=view&id=14&Itemid=29 but they are expensive, I just want a kit that has all the O-rings, gaskets, needles and floats. or some where I can piece together my own kit, thank you.
O-rings: (for 4 carbs, but it's cheap, leaving you extras) You want the kit for mikuni BS carbs 80-84
Most everything else: http://www.mikesxs.net rebuild kit (needle, seat, gasket, and pilot jet plug) is out of stock
I got my needle and gasket here: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=200474693262 I did have a problem though. With the clip that attaches the needle to the float they would not seal. They are just a hair too short. I removed the clip, and they worked fine. I didn't use the gaskets yet, as mine still seal very well.
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A fluke is a good meter so should be OK, but they can go out.
I'm assuming you replaced the burnt out diode?
When you turn on the ignition you get the full battery voltage down at the generator end of the field winding? it should not be more then .5 volt different from the battery.
With the engine running and the 3 phase output connected to the rectifier you see the same AC value on each of the phases? rev the engine as well and note the change.
When you switch the bike off and connect the meter in current mode, in series with the battery negative lead and the battery there is 0 current flow?
Yeah, did replace the diode.
I load tested it today, and got no load with the key off, and 4.25V with the key on.
Now for the voltage readings:
Idle:
Battery: 12.25V
Generator: ~10.6V on all 3 legs
Field Coil: 10.35V <<seem odd?
2,000 RPMs:
Battery: ~13.5V
Generator: ~12.5V on all 3 legs
Field Coil: 12.25V <<seem odd?
2,500 RPMs:
Battery: 13.5-14V
Generator: ~13V on all 3 legs
Field Coil: 8.8V <<seem odd?
All of the voltage readings fluctuate a bit, and will vary because I would do 1 @ all RPM ranges, then the next. I never got above 14.15V or so, and it would fall below 14 if I stayed above 2500RPMs or so.
It seems to be keeping up (not great) as long as I don't turn on the blinkers, or brake lights while idling. When I do it drops voltage, and can't seem to catch up.
I have another field coil, but it's well used, and ohms out almost identical to the one that's on the bike now.
My replacement plug caps will hopefully be in by Friday.
The service manual isn't very explicit about replacing the stator, and field coil. Is that area filled with oil? Do I need to replace gaskets if I open it?
Thanks Again For The Help
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The front brake switch is in the brake lever perch. 2 going in, brown, and green/yellow.
You could disconnect the rear switch, should have bullet connectors on it. If the lights still on, probably the front switch.
Thenn try unplugging the front switch. I believe the plug is in the headlight bucket.
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That rectifier is OK. 3meg ohm is considered no continuity, although I'd expect to see 7 meg, but if all the readings are the same I'd say that's good to go.
A .5 volt on diode test is about right, it should be .6 so I'd guess your meter is off. If it cost less then £100 and hasn't been calibrated your meter not being accurate is more likely then 6 diodes having failed to give the same readings.
Leave the rectifier alone now and turn your attention to another part of the system!
There is most definately not enough of a difference in voltage between engine off and charging. You need to see about 14.5 to 14.7 volts with it charging and head lamp on.
What is the resistance of the FIELD winding? If it is less then stock I'd say that's your problem.
What should the resistance of this winding be? And what is yours?
Thanks for the reply.
The field coil should be 4Ω ±15% Mine is at 3.4Ω which is right at the bottom end.
I have (2) regulators that both ohmed out the same, (2) rectifiers that both ohmed out the same, (2) stators that both ohmed out the same, and (2) field coils that both ohmed out the same. These are all used. The extra rectifier was on the bike, the regulator I bought off ebay (stock regulator was already replaced), and the stator, and coil were a surprise in a parts lot I bought.
I think the previous owner was trying to track down this problem, and failed. Like I mentioned the Regulator, and Rectifier were already replaced. The headlight was also on a switch when I bout it. I assumed it was because the diode on the headlight circuit had shorted out, and previous owner hadn't found it. May have been been, but may have also been because it was a drain on the system.
The only other thing that I've noticed on the bike that is not right is 1 resister cap is leaking. It tests out at 10kΩ, but if I touch it with the bike running I'll get a shock. I verified it is the problem by switching the ccap to the other cylinder, and got the same result. This couldn't effect the charging system could it? The other cap ohms out at like 3MΩ.
My meter is a Fluke 83 III, so not a cheap meter, but never been calibrated. Ive had it for years, but looks like new. I take good care of it. Will look into getting it calibrated though.
What size tires can I fit on an 82 XS400SJ?
in Classics
Posted
Thanks for the replies guys.
The supplemental from Yamaha does have 120/90 listed for the rear. It doesn't list the rim size for front or rear though.