Total Motorcycle Community Forums

I recently purchased an 82 Yamaha XS400J Maxim with 11K miles in reasonably good condition. It ran, but wouldn't rev over idle. The stated problem was that it needed a carburetor cleaning and balance. I bought several manuals and rebuilt the carbs, but on the way I noticed the manual said don't do the carbs without adjusting the valves. So I pulled the top end off and checked clearance. It measured .0015 to .002 on all valves, which is way under the .004/.006 specified. That really surprised me as I expected it to be loose, not tight. Is this normal, and how did it run? Given that I must now get the right shims to set the valves up, where does one get special tools for this bike? Two that I need are the valve depressor tool which allows me to change the shims, and the adapter that pushes into the carburetors to allow monitoring the carb float height. I can find shims, gaskets, jets, etc. but not many tools. Any ideas?

if you need a valve spring compressor etc... tools can be found at www.mikesxs.net..

To check carb float level, remove carb float bowl and adjust tang on float so that the float itself is parallel to carb body. This adjustment is good enough for accurate float height-or if you really want to you can find float height in mm, and again measure from float to carb body.