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How did you make out with your single carb? I am in the process of converting my bobber to a single carb, although mine has a somewhat more radical intake putting the carb facing forward by the left cylinder. The carb I got is off a snowmobile. It starts and runs, but is a little rich. I don't think I am far off though. What are you running for jets?

Thanks. I had already looked at that thread, but it did not have any info on wiring the rectifier properly, that I could see . How can I find out which white wire goes to which terminal? My XS400 diagram in the Haynes is not specific as to the order, and the plug has been removed so I can't just check.

I have an 81 XS400 that I have chopped and hardtailed and rode all last year. I took it apart this winter and painted it, etc. and I decided to rewire it rather than use the loom I made up last year, to do a neater job than the first time around. Anyway, I cannot get it to charge. It starts fine, runs great, but sits at 12v or less. The wiring is very simplified, as I have removed the starter circuit, among other things. I have the regulator, rectifier, and ignitor box at the moment. All are wired the same as last year as far as I can tell, I used the same diagram. Does it matter which white wire goes to which on the rectifier? Where shouldI start looking? I tested the regulator according to the manual I have but none of the readings are even close. It said to test the ground by bridging the black wire and the regulator case, but that did nothing. Can I test the alternator by itself, to see if it producing voltage at all? I pulled the alternator cover off and everything appears to be in good condition under there, no burnt wiring or damage to the components. There is oil under the cover but considering there is hole betwen the crank case and alt cover I assume it is supposed to have oil. Is there a universal or upgraded or universal regulator/rectifier that I can use? I'd appreciate any help. Thanks

I have an 81 XS400 Heritage that I hardtailed and bobbed. I am wondering if there is another alternative to the stock 33mm forks and wheel on my XS400. I want to put a spoked front wheel with drum brake on the bike instead of the heritage special mag wheel and rotor. Either want to find a wheel assembly that will work with the current forks, or better yet, a fork and wheel assembly that will fit in the triple tree clamps. I don't need the speedo. I can get a new axle machined with spacers if it is close to the proper width. Any ideas? For instance, I know that the old CB350 and others had 33mm forks.

Just a Heritage Special

I have the mag wheels on my XS400 (1982) but would like to switch to a spoke type wheel on the front. What do I need to do to make this work? Any models that will let me use the original forks, brakes, etc?

Knew someone could help, thanks a lot!

I am stretching my 400 and adding a hardtail. I wrote down all the measurments for my swingarm and stuff but cannot find it now (my swingarm is chopped up now). Before I bend the tubing for the hardtail, I'd like to confirm my length. It just looks like quite a stretch in the jig. An approximate measurement from the center of the axle pivot to the end of the swingarm would give me a good idea.

Does anyone know what the width of the rear wheel (axle) between the axle plates is on an XS400 Mine has mag wheels if that matters. Mine is at 7-15/16" inside to inside on the axle plates, but I want to make sure. I am building a hardtail and want it right the first time!

I had my bike out last night (82 XS400) for a ride and adjusted mixtures. Everything is running great, starts good, idles when cold at 1200. However, once it warms up the idle sticks at about 3000 but as soon as I cover the right side carb throat (no airbox) for a second it drops to 1200 and stays there. Sticky slide?

Thanks, was not sure if it added air to the mix or limited it...

On my 82 xs400, the mixture screw is on the engine side of the carb. To adjust, screw out to make it rich?

I have an 82 XS400 I had my bike going today and it was running fine. I slowly got worse through the day until is started "chugging" and losing power at higher rpm. I took the carbs apart again thinking there was some new dirt, but went a step further than before. I pushed out the needle tube and it was filthy and plugged. Cleaned it up, cleaned the holes, etc. Put the carb back together and now it won't start! Took the float bowls off and checked the floats, noticed they were binding a bit so I cleaned out the pivots good. The float bowl lwvwl does not seem to be enough but the tangs are already bent some. Also, if I leave the bike to sit, fuel runs out of it like crazy in the filter side of the carb. I disabled the vaccum petcock, but fuel should not pour out when it is sitting, shold it? Question, when I first too kthe carbs apart, there was a rubber plug in one of the jets, the small one. Why would it be plugged, and is it supposed to be?

Update again I found the problem, one of the terminals int the plug to the ignitor was busted in two. Replaced an away I go. Took me 7 hours and tearing half my bike apart to find it. I checked that plug about 6 times before I noticed it...

Update : now I have nothing, no spark at all. I have checked all the connection to all the plugs and cleaned them, I opened the ignitor box to see if I can see any damage, nothing at all, no solders cracked, no hot spots, etc. I checked the off/run/on switch and it seems to be working. Cleand and checked the conections inside the headlamp. I guess I need to know how to test the ignitor, the rectifier, etc. I don't have access to any parts bikes so this could be difficult.

I have an 82 XS400 with electronic ignition. The last time I had my bike running it was fine. It sat for about 12 days in the garage, battery unhooked most of it. I installed a new battery today (freshly charged) and it would not start, turned over and over and then one huge backfire. I pulled the left plug and had no spark. Here are the symptoms -I shorted the battery by accident to the frame while I was installing it. -Sometime I get a spark in the right cylinder, sometimes not. -When the right cylinder is working, if I swap the signal wires to the coils I will get spark in the left cylinder, none in the right. -After the starter runs and stops, there is a pause and then a spark on the right cylinder (discharge?) -I checked all the plugs leading to the coils, the pickup coil, etc. -I am using a booster pack for a battery power.

I broke the brake lever on my bike tonight. I have an 82 Heritage Special, but when I look up parts for it I never seem to get the right thing. I went to http://www.cmsnl.com/yamaha-xs400sh-1981_model8826/partslist/ and looked at an 81 model and it seems to have the right lever. Yamaha no. 4L08392200 Does anyone know if Motion Pro makes a lever to match? I come up with 14-0506 as a match. I think 14-0510 is the cable version, mine has a disc brake.

I am wondering if there are part numbers or metric sizes of the steering stem bearings and races on my 1982 XS400? I am hoping I can just buy the bearings off the shelf at a bearing place or parts store rather than going through a dealer. Not one of the parts I ordered for my bike from the local dealers has been correct yet, and they don't seem to know or care about old bikes. Let me know, thanks

I'll get a pic

Had great success with the carbs today. Cleaned them again, found out I missed a little screen in the fuel supply tube for one thing, laquered almost solid. The petcok diaphram was no good, so I just removed it. Blew out all the other orifices and set the floats the best I could (specs didn't seem to match, but at least they are even now). Goes like hell now! Well, as fast as a 400 goes like hell.

Thanks for your help. The code is 14W 000950 I'm gonna go over the carbs again today.

Hi New to forum, but will probably be looking for lots of advise as I get this bike running and customized. I am planning on a bobber project, but before that I want to get everything running well and working properly so I can put it through a government inspection. Then out comes the grinder. The bike has not been registered for 18yrs, and has been sitting inside all that time. It only has 3600kms on it, and has been owned by one person. Howerver, it was not stored properly and of course the carbs are fouled up pretty good. I downloaded a manual for the xs360/400 series of bikes, but I need a little help identifying the exact model I have. The owner had no original paperwork, so I don't have a lot of information to work with. Can anyone tell me if I have a D,E, 2E, 2F, G/SG, H ? I need to get the float bowl settings and stuff so I can get it running better. Also, these are the symptoms I am dealing with. I have good compression on both cylinders. I have dismantled and cleaned the carbs (maybe not good enough, probably going to do it again). I have cleaned the tank and pickup. The bike will start and idle pretty good with the choke, but it shuts off immediatly when the choke is shut off. Also, if you can get it to rev a bit is backfires out the exhaust and sometime back through the carb. I can seem to get any more than 6000 rpm out of it either. I am thinking either the vacuum operated petcok is not supplying enough fuel, or the float bowls are not set properly. Any other suggestions?