jordanscycles

id take the clutch plates out and spray them down with WD-40. had the same problem with a 1972 dt 125

The only new ones I can find are $140 each , and I'd like to buy new if possible.

could it be the clutch plates?

your lights would be dim unless you were revving it if it could even spark hot enough to start. also LED turn signals are 12 volts and I'm pretty sure that bike is 6v.

Thanks for the reply. It ended up being that the previous owner had worn the battery to hell and it wouldn't hold a charge. Went through the carbs, new dry cell battery, new fuel line, rebuilt petcocks, lined gas tank.. starts in two kicks and runs like a clock.

So if the bike is not charging the battery well or at all, then where would I go from there? Replace the rectifier? A new problem for me, advice appreciated. Also, the previous owner put in pod filters, and I'd like to know what jets to get for it or just put the original air box back in which he gave me.

well you can get the parts from a yamaha dealership, http://www.bikebandit.com, http://www.ebay.com (obviously :>), http://www.nwvintagecycleparts.com/ which specializes in NOS yamaha and kawasaki parts. also I got a 1978 xs 400 myself, great bike.

to start you should let it idle for 10 minutes. then take it easy, but be sure to do that first as an initial break in.

http://cgi.ebay.com/ebaymotors/1992-FZR-10...sQ5fAccessories

you could try adjusting the clutch adjuster on the opposite side cover from the clutch plates, should be the side cover that covers the front sprocket. you should loosen the nut, then screw the screw in until it hits the rod then tighten the nut to make it stay. might be covered by a rubber cap, might be underneath the plate, but I think that it's your problem.

might be seized. I'd try cranking it with a wrench hooked to the crankshaft to make sure it isn't. if it's not I'd think your solinoid went bad.

buy new plugs, check voltage to the coils, could need a carb rebuild or cleaning but that bike might be fuel injected so maybe not, check for leaks in the intake manifolds, airbox boots, either one would cause it to suck in excess air reducing performance... does the problem apply to neutral as well? check the wheel bearings by making sure it rolls freely, dragging brakes, valve adjustment might be needed, weak spark caused by an old battery, etc etc

well I'd buy new spark plugs, check voltage to the coil, make sure the spark plug boot has a good connection, clean the carbs maybe?.. good place to start

i wouldn't worry about it as long as it's effective.

There's a tube coming out of the top of my transmission that connects to the airbox, but what I'm curious about is what this is for. I just read that if you cool the transmission it works better? so maybe it circulates cool air into there? anyone have an insight on this?

i heard this thread was old

buy a new plug and stick it in or just shove the old one back in good luck!

yeah if the plug doesnt fix it you should open up the carb and make sure the jets are cleared. the idle jet will be the smaller one and the main jet is the larger one, more likely your idle jet is partially blocked so you can clear it with a piece of wire or go to a dealership and get a jet clearing tool for like $10. or it could just need to be tuned, the mixture screws on the carburetor should be screwed all the way in then backed out 1 and 1/4th turns. Also if you're going to buy a new plug make sure to look up what plug it is in the microfiche, instead of just going off what's in the bike since you've never changed it, so you can ask the dealer if you were going to get the plug there anyway or just look it up yourself.

buy a new battery

i use 132.5 mains and 42.5 idle jets.

you say you messed with the air screw, now the air screw would be behind the slide, but a fuel mixture screw is in front of the slide (engine side). So if you unscrewed that you are letting in more fuel then necessary. I would bottom out the screw then back if off 1 and a quarter turns. That's where it should be in general, and will make the bike run leaner, since you're too rich. Also be careful screwing in the screw to bottom it out, if you do it too hard itll break the needle down inside, so just be gentle. good luck

i don't know. I'd call it a 50-50. and it's a rear wheel... i don't know if those were different widths on the xs 650's i think they were the same on the 400's so maybe, sorry man someone else might know

You can get a cast wheel which would be what yamaha used for disc brakes on the xs 400's like ours... And most bikes. You could probably get one off eBay. The only thing I would be concerned with the hydraulic brake line fitting into the ya 250 master cylinder and the yamaha caliper but it might I've never done it. If it fits though that'd be sweet.

also make sure your floats float

new wheel, new caliper, and why not just buy a used yamaha xs 400 front brake set up, instead of messing with after market pieces for dirtbikes.