OllieB

Interesting! I have seen both views posted over the past couple years. In my case, the red bulbs work perfectly and since I don't plan on buying another set of white, i'll never know!

Since you have a 1980, you have solid state ignition - no points to check!! You are correct, there is a metal plug inserted at the factory over the top of the rear screw blocking it from removal by folks like us. You must carefully drill out the plug with a drill bit just a little smaller than the opening in the cover. This will allow you to get to the screw so you can inspect the innards. Yes, your plugs do look a little sooty but did you do a nice long run before removing and checking them? If not, there will be more carbon build up resulting from a lot of idling and/or short, low speed run. Best to ride a bunch of miles at speed before checking the plugs. They should be light grey/tan on the top electrode. About 3 turns out seems proper. Did you replace the VERY SMALL o-rings on the idle mix screws? ps - like your helper! I have two, a Boxer and a Great Dane, who like to have their heads right in there with me as I work on projects.

I can't tell you which design is correct for your model and year bike but Pit Replica is pretty knowledgeable about these covers. The one for my '80 XS400 came from them and they are currently making one for my son's '81 XS400 - a different style from the one on the '80. The seat cover style often changed from year to year. In addition, seats were sometimes replaced by previous owners with better condition ones from other year bikes. Besides verifying the actual year of your bike, you need to search the web to find some pics of your year that are supposed to have the correct seat. All this adds to the frustration and fun of outfitting older bikes! =:-)

From 1980 on, these bikes had solid state ignition, not points, hence the black module. You are going about it the right way. For those w/o any knowledge of engines, it is indeed a steep learning curve but you can do it. Lots of folks here in the U.S. experienced the same a couple years ago when our gas prices went up to $4/U.S. gallon. Thousands bought the cheap Chinese scoots from Internet vendors ("dealers" in name only) and found themselves with a machine they had to assemble, prep and trouble shoot to get it running properly. With the help from forums such as this, folks like yourself slowly became knowledgeable about small carbureted engines and how to maintain them. It also helps if you can find a local friend with some knowledge. Keep at it and you will have a feeling of accomplishment in the end. Lots of very knowledgeable folks here will assist you.

Great! Glad it all turned out well for you. That 7" headlight looks huge in the XS400 housing. Bet it gives a good light pattern on the road. So, am I off the hook as far as the LED tail/stop bulbs are concerned?

"Silikroil" - one of the absolute best penetrating oils made!! http://www.amazon.com/Kano-SiliKroil-Penetrating-Solvent-SILIKROIL/dp/B0003041WK

Sounds like your problem was a loose and/or corroded terminal/connection. Only questioned the light compatibility and wiring because you didn't include much info. Yes, it would be good to go over the grounds on a bike as old as ours. Good luck on your ride.

On something like that, without being there it is hard to say. Could it be your battery is failing? You say there is juice the minute you touch the battery terminal - could the terminal be loose inside the battery and not making contact internally until some force is applied to the terminal? Had a battery do that once. Is the battery new or old and is it fully charged by an external charger, not the system on the bike? All this assuming your wiring job is correct and the light units are compatible and not defective.

Thanks!!

Depends somewhat on your personal circumstances and preference. How many miles/year are you putting on your bike? If it is several thousand, you might want to consider one of the long range types. For stock ignition systems on our older bikes, I prefer standard NGK or the Nology Silver over platinum or iridium. If you have installed a higher energy ignition coil, you can move to the iridium with non-resistor caps. I usually don't put more than 1-1.5K miles on my bike each year. At those miles, the standard NGK plugs will last many years with little attention except maybe gap check every 5K miles. One of the concerns with platinum or iridium plugs and standard energy coils is that there may be some spark "blow out" or erosion at higher rpms resulting in a possible high speed miss. Weaker spark and a very thin center electrode is thought to be the cause. Some folks successfully use platinum/iridium plugs with standard energy ignitions w/o problems while others experience problems. Some electronic ignition systems don't like double resistors - cap plus plug. I am all for reduction of maintenance and that's why I like the Nology Silver for special applications like our older bikes and my older Benz autos. Without checking records I think the Nology plugs have been in my '90 300E 2.6 for 20-30K w/o the need for re-gapping. I only have 4.5K miles on my scoot so no long term results.

This is one of my favorite topics! Platinum and iridium spark plugs were developed because the industry needed plugs that would go the longer haul with less gap erosion so the state of tune of an engine would last longer and pollute less. If used in a setup with a high energy ignition system, they are fine. If used in an older machine that does not have a high energy ignition system they can actually degrade performance to some degree. Platinum and iridium plugs are all resistor type plugs. I have two older Benz gassers that specify non-resistor copper electrode spark plugs. The resistors are built into the plug caps, just like our older bikes. If a set of platinum or iridium plugs are installed, along with the stock resistor caps, problems may develop. In addition, platinum and iridium are high resistance metals and some spark energy is lost because of this. Couple this with a lower spark energy ignition system and a weaker spark may result. For our older, lower energy ignition systems, my preference is to stay with the stock resistor caps, metal core ignition wires and either the non-resistor steel electrode plugs (NGK) or Nology Silver electrode plugs. Check out the link below to Nology's site and see what they have to say about electrode resistance for the various types of metals used for spark plug electrodes. Also, because of the design of the Nology Silver plugs, they have a wider heat range than standard plugs. Ones for our machines are heat range 6-8. Nology Silver plugs are available for our XS400 machines but they are a little pricey - under $10 each if you shop around. I run sets in both my Benz cars and my scoot. Have not yet purchased them for the XS400 but plan to. Silver electrode plugs also have a longer life expectancy than steel electrode plugs. http://www.nology.com/silver.html

Thanks kindest! I edited the original post with a link to the seller's ebay store and a description of the specific bulb description since links to "for sale" items are always expiring.

LED tail light update: I posted this info in the headlight upgrade thread where this was discussed but thought it was important enough to start a new thread: Just received the pair of super bright LED #1157 tail/stop bulbs I ordered from Ebay. I have used the seller in the past with good results. Installed the bulbs and they are practically as bright as the filament type - only a very slight difference. Far better that the other, flatter style you usually find in auto parts stores. I am totally satisfied with the results. They are a little pricey but they are high quality. Power test: with engine running and headlight on high beam (60w), no headlight dimming when the brake(s) are applied. Not so with the stock filament bulbs - the headlight dims noticeably when brake(s) are applied. Remember, I have an H4 SilverStar Ultra 55/60w bulb in a new 6 3/8" CandlePower motorcycle reflector. I can highly recommend these super bright #1157 LED bulbs to folks wanting to take a little strain off the charging system after installing a higher wattage headlight. The link below is to the seller's ebay store. Since links to specific listings change all the time, you want bulbs with this description: "2pcs 1157 13W High Power LED red Stop/Tail Bulbs". Refractor style LED bulbs are also offered which project more to the side. Since I have not tested these, I can't comment on their effectiveness. http://stores.ebay.com/warden-jp2008/_i.html?_nkw=1157&submit=Search&_sid=1006980729

LED tail light update: Just got the pair of super bright LED #1157 Tail/stop bulbs I ordered from Ebay. I have used the seller in the past with good results. Installed the bulbs and they are practically as bright as the filament type - only a very slight difference. Far better that the other, flatter style you usually find in auto parts stores. I am totally satisfied with the results. The only possible mistake I made was when I ordered the red LED bulbs instead of the white bulbs. Since our reflector is already red, the white LEDs might have been slightly brighter behind the reflector. Forgot that little fact since I was into this with my scoot a couple of years ago. They are a little pricey but they are high quality. Power test: with engine running and headlight on high beam, no headlight dimming when the brake(s) are applied. Not so with the stock filament bulbs - the headlight dims noticeably when brake(s) are applied. Remember, I have an H4 SilverStar 55/60w bulb in a 6 3/8" CandlePower reflector. I can highly recommend these to folks wanting to take a little strain off the charging system after installing a higher wattage headlight. http://cgi.ebay.com/ebaymotors/2pcs-1157-13W-High-Power-LED-White-Stop-Tail-Bulbs-_W0QQcmdZViewItemQQhashZitem2c5745737aQQitemZ190442730362QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ht_798wt_1167

You haven't told us how much you have run your new bike on the old gas. Best to siphon that stuff out if you know or suspect it to be around a year old or older. Then run the bike a bunch of miles with the new gas before you pull a plug and evaluate it. Short runs won't give you an accurate plug read. Yes, gas can deteriorate on standing.

I am sure you will be on the safe side with the brake leak but be careful as the front brake does the majority of the braking. Can you determine just where the leak is coming from? Could it be something as simple as the brake hose attachment banjo bolt or caliper bleed screw needing a slight bit of tightening? BTW, manometer looks good!

Thanks for the information!!

Yep, o-ring at very bottom. With the plugs still in there, I am surprised the o-rings are in such good shape. Maybe someone previously replaced them and installed new plugs like come with MikesXS kits. Who knows!!

.... and gear selector shaft seal.

Factory setting to reduce emissions and comply with EPA regs was 1.5 turns. I just installed new idle mix kits on my '80 yesterday. While the plugs had already been drilled out, there were o-rings down at the bottom of the opening. The o-rings are very small and get flattened. Could you have missed them? Order of parts install: coil spring, small washer, o-ring. The o-rings are VERY SMALL. Without the o-rings you will have vacuum leaks and not be able to get proper adjustment. It made quite a difference on my bike. Get 2 new choke rod seals also. Mine were very hard and broke apart as I took them off. Be careful to not loose the small ball bearings located inside each rod guide as you slide the choke rod out. Best to unscrew the enricher plunger mechanism and pull the plunger out of the nut to make it easy to install the new seal.

Today I installed the idle screw kits and choke rod seals I got from MikesXS. Wanted to wait until I got the butterfly shaft rod seals but they are out of stock and I couldn't get any info on when they would be back in stock. All I can say is that the difference is amazing!! Dust cover plugs had already been removed by a previous owner so the job was a little easier. The o-rings on the idle screws were still in one piece but were quite firm and somewhat deformed. The screw tips were in good shape but I installed the new set from the kit. The choke rod gaskets on the bike were very hard and broke apart as I removed them. After removing the choke rod and being careful not to loose the small ball bearings in the rod guides, the easiest way to install the new seals is to use a wrench to remove the enrichers. You can then slide the shaft out and more easily install the seals over the retaining lip. Of course, the carbs need to be removed - not a difficult job. After putting everything back together I set the idle mixture screws to 2 turns out. The bike started instantly and smoothly with a good fast idle and settled to a good idle after the choke was pushed in. After a test ride I turned each screw out 1/4 more because the bike acted like it was just a little lean. Will test and increase the setting by 1/4 turn increments if needed. I had been chasing the "high idle after engine heats up" issue and knew the cause was most likely the idle screw o-ring and/or the other seals. Guys new to these older bikes - like me - take heed of the expert advice given here by the experienced guys.

My original fuse box was still in place but all the circuits were nicely rewired using twist lock glass fuse holders and they were tucked underneath the old fuse box. When I removed the top of the old fuse box and touched one of the tangs which hold the fuses in place, it broke right off - brittle with age and, I believe, exposure to battery acid fumes resulting from lack of attachment of battery vent hose. I kept the new fuse holders but bought a repro fuse box from the U.K. just to have the original look. I am betting on a bad battery. In the U.S. you can get an AGM battery from NAPA that has a 1 year free over-the-counter replacement warranty. Many places only offer a 6 mo. warranty. When i bought my bike in June, the seller said the battery was new last Summer but that I wouldn't start the engine very good and that maybe the starter was bad. All that was needed was a complete, proper charge and it has been perfect ever since.

Good point!! better to try the easy stuff first.

Yeah, congrats!!

And, there aren't any LED headlights out there that will give you the light needed for night time riding. Just replaced my original type sealed beam 35/50 watt headlight with a 6 3/8" one from "Candlepower". It takes 55/60 watt H4 replaceable bulbs as mentioned in the above linked thread. Great side-to-side lighting and down-the-highway projection.