20 Most Recent 1985 Honda XR 250 R Questions & Answers

km ? probably vlave clearance on the exhaust slack on the distribution chain could also be ... i had the same bike and year ...just a general overhaul of cilinderhead and chain will do...

Sorry. I'm very certain you can't fix your problem without splitting the case. I would be cautious about running the motor at all. When you removed that bolt those pieces are free to fall down to the bottom of the case to interfere and do damage. Good Luck.

Air blowing back from the carbs is a sign your intake valves are leaking. They do this when there is not enough gap between the valves and the rocker that opens the valves. They need to be set to 0.003 inches when cold and with the piston at top dead center of the compression/power stroke

Probably only needs a new Spark Plug!

Check fuel float bowl level, idle jet must be working but main jet could be Blocked. Also throttle cable may not be hooked up to throttle slide .

has nothing to do with valve clearance! You are running to lean at idle. Your idle jet is most likely plugged up! Do not drill out, blow out with carb cleaner and compressor. If it is too plugged up replace it. Mixture screw should be at about 2 turns out. Im guessing right now it will only idle with the choke on, or run with the choke partially on. When you let off the throttle off, deceleration it back fires the most. I do recommend having a trained tech service the carb!

Do not use a universal CDI unless you have the exact wiring cross-over diagram, or have tech help from the manufacturer. You can short out the CDI and other ignition components like the stator.