Questioni have a '88 xr80r, i was trying to tune it up a little, and i turned the screws on the carb and now i cant get it to start. where should they be set at. i took off the carb and blew out all the jets, put back together and nothing. need your help bad.
AnswerJohn, you can review parts illustrations at:
http://houseofmotorcycles.bikebandit.com/honda-motorcycle-xr80r-1988/o/m3141
BE SURE that the idle jet is clear and clean #35 size, in most cases. If that jet is plugged up, it WILL NOT start and idle.
You have two screws there... one has a sharp point on the end... FUEL SCREW for idle mixture.
Dull-ended one goes into the middle of the carb body and raises the throttle slide up, increasing idle SPEED.
With the air filter off, so you can watch the carb slide, back out the speed screw until you see the slide drop to the bottom of the carb body bore. Then, very gently, turn the screw in until you see it just barely raise the slide up from the bottom. About 1/8 turn is all you should need.
The idle mixture screw should be out about 1 to 1 3/4 turn out from gently seated in. That is the setting for the earlier machines, which may or may not have a fuel screw, vs an air screw, used on earlier model Hondas. Somewhere in that 1 to 2 range, should be sufficient to get the engine to run and idle somewhat.
BEFORE YOU CONTINUE TO kick the daylights out of this thing remember to
1. Set the valves to .002" cold on intake and exhaust valves.. at T mark (compression stroke).
2. Clean and adjust the ignition points, so they just open at the F mark alignment on the flywheel (compression stroke). Gap should be around .012-.016"
Check for spark and compression, then put in a fresh non-fouled spark plug and have at it. Unless you have other undefined issues like bas spark plug cap, sticking float valve or incorrect float level, the bike "should" start right up again.
Bill Silver
