Hey folks-

 

87 GL with EA82 Carbureted - wouldn't idle at all, so i pulled the top off the carb, and cleaned out the idle jet. Now it's idling, after adjusting the throttle screw and the idle adjust screw. (BTW What is the correct setting/procedure for tuning these??)

 

It idles at about 800-900 rpms, but after warming up a bit, it will slowly jump to 1500, then back down, about every 2-3 seconds. Can't seem to wrap my head around this one, any ideas??

 

Also, if I revv the engine up to about 3000-3500 rpms quickly, and then let go, it will backfire out the exhaust. It wasn't doing this when the idle jet was clogged...

 

Suggestions/ideas much appreciated - thanks!

Could be just about anything - Hitachi's are finiky like that. If you really want it to work correctly tear the carb down and rebuild it properly - resetting everything to factory adjustment.

 

Your backfireing is the only thing that's probably not entirely the fault of the carb - you are getting fresh oxygen into the exhaust probably somewhere in the y-pipe. Either the AIS valves are broken or there are holes/gasket leaks, etc in the y-pipe.

 

GD