xmastree

Does the green light stay on when you press the starter? Is there anything at all happening? relay clicking, panel lights dimming slightly? Have you checked the kill switch?

They all do that sir, it's a feature on this model. I have one just like it. Pilot jets blocked, apparently. Clutch dragging? Put it in gear (engine off...) pull the clutch and try to move the bike. The clutch might need adjusting.

http://shop.wemoto.com/index.dyn?flag=17&make=Yamaha

Hmm, when my XJ750 did that it was because I had the plug leads on wrong. I had 1&3 together, and 2&4 when it ought to have been 1&4 and 2&3. Might be worth checking, what bike is it?

Having done the valve clearances (and fitted new plugs), I tried to fire it up... Nothing at all, not even trying to fire. Then I noticed that whilst I had the throttle cable off, it had become dislodged at the twistgrip end and the throttle wasn't fully closing. There was a gap of about 1/4" at the idle adjuster screw. Fixed that and it fired, but still only on the left cylinder. Then it died. It would only start with full choke and absolutely no throttle. And only on one cylinder. Trying to open the throttle kills it instantly, and it will just about keep going after about the fourth attempt. Then, slowly, the throttle can be opened and the speed will increase. Eventually the right hand cylinder kicks in and it will warm up and settle nicely. It doesn't rev well though, spluttering before revving if the throttle is opened quickly. I'm suspecting the carbs...

Oh yeah, they swapped them without question, but they had to order them rather than get them from their workshop. Originally, the guy said if the clearances still weren't right, they would take back the shims and give me different ones. Which they don't have to do really. I'm not sure they'd do that with these.

The three white wires will be the three phase AC from the generator. They go to the reg/rec which charges the battery. Nothing to do with the ignition. The other two will be from the ignition pickup coil, and should connect to the CDI to trigger the spark. Probably...

Having finally found a manual for my old XS400 DOHC, I set about checking the valve clearances. Sure enough, they were all tight. One had no clearance at all, and that was the cylinder which doesn't like to play at first. So, duly measured, noted and calculated I went to the shop to buy the three I needed. Tried to fit them last weekend only to find out they were too small. Not the thickness, but the diameter. They're the wrong shims. Back to the shop today, and they have to order them... I suppose their offer of "If you got the thicknesses wrong, bring them back and we'll change them" has expired now... Arse.

Yeah, I made something similar when I did my XS400. Filled it with fork oil. One thing to watch out for, if the carbs are far out, the oil can get sucked into one cylinder.

Woo hoo! I found a service manual online. I won't post the link as it's probably illegal. Let's just say it was a torrent on piratebay.org.

What I ought to do is try the local Yamaha dealers, they should have a big book saying what needs what. They may also be able to advise me about the valve clearances, so long as I promise to buy the shims from them...

Hmm, that link doesn't work, and going from the top to search for my XS400 reveals that they don't exist after 1982 (the SOCH model) and they don't even have plugs for that one...

Interesting, thanks. Although the service data isn't the most legible scan I've seen... By enlarging it, blurring slightly and squinting at it, I can just about make out: valve clearance (cold) Intake/Exhaust | 0.51 ~ 0.58mm / 0.15 ~ 0.20mm The exhaust I can believe, but I'm not sure about the inlet.

Try: http://www.kchops.slide.com/ What's it supposed to be?

So, I have this old XS400 DOHC, which has been idle for a few years. I've fettled it to a point, and it's on the road, but not as good as it could be. Pics here During the fettling, I had the carbs off and had them ultrasonically cleaned. Firstly, starting is a pain. It tends to fire up instantly, then die after about two seconds. After that it takes a lot of cranking, it will catch, but I can't get it to stay running. Any throttle action and it just dies. Mostly, it's one cylinder doing all the work, and this post caught my eye. I would like to check the valve clearances and ignition timing but I have no data to work from. Also, I should replace the spark plugs, but rather than assume it has the right ones fitted, I would like to know what they ought to be. The speedo reads really slow. Following a friend at 30,40,50,60 on his, mine reads 20,25,30,40. The trip counter seems to be reading low too, suggesting the problem lies with the speedo drive rather than the speedo itself. In 6th gear, at 6000rpm, the speedo reads 65mph, but it feels much faster. The tacho is very sluggish. At standstill I can rev it up to what sounds painful, and back again and the needle only reaches 2000. Holding it at 4000 then killing the engine, it takes 4 seconds to drop. On the road, up through the gears and it hardly moves. As if it's full of oil or something. What tyre pressures should I use? Dunlop Arrowmax, 100/90x18 and 120/90x18 Does anyone produce a manual for this thing? Edit: Any idea if this will be any good? At £17 it's a tad expensive, and at 20 pages it isn't going to be a workshop manual either.

Hi all, new to the forums here so I thought I'd introduce myself. I recently bought an XS400 DOHC project on eBay for £100. Complete, but hadn't run for six years so I reckoned it was worth a shot. Having got the beast home, and had a poke around, it wasn't that bad really. It's all there, but the tax disc says 2001 which gives a clue as to when it was last used. The fusebox had some issues: But that was fixed with an MG Midget one from eBay: (I have since fitted the correct fuses) There were barnacles under the filler cap: And as expected, once I got the carbs off I found this inside: Still, nothing that couldn't be sorted. It's back on the road now, but far from perfect. I want to do the valve clearances, but I don't know what they ought to be. Likewise the ignition timing. I have no information at all about the beast, and I can't find a manual anywhere either. Remember, it's the DOHC model, so the Haynes one doesn't cover it. So, I'm hoping to pick some brains around here (and share my limited knowledge too), and maybe with some help I cen get it running as well as it should. Cheers.

I recently paid £100 on eBay for an 1984 XS400 which hadn't run for years. In that respect, £200 sounds like a decent offer although I think I got a bargain. It cost me less that £100 to get it on the road.