Honda CB550, engine running rough, need ideas?

C

Charlie

New member
Hey everyone, I'm back with a new one.
1975 Honda CB550 K1.
Recently laid the bike down on the right side (points/crank cover on side of engine was dented inward but no cracked timing plate). Was running fine until the wreck, then it was not starting. I took the carbs apart and cleaned em out (lots of dirt and gunk from gasket material in there) and now it runs but is really rough at idle.
It still gets plenty of power accelerating and doesn't appear to run too rough in the high end, but in the low end, one of the pipes (dual exhaust) has a hammering/rough sound and it pops at idle as though it's not burning the gas right. Also the exhaust smells like it's not burning right. Dies at idle when cold.
Any ideas are great. Just need to know where to start. I'm thinking maybe adjust the mix, maybe the timing is off or chain is loose? Thanks
 
There's a good chance you plugged an idle jet when you cleaned the carbs. Also a good chance you got them out of sync, which would make it idle bad and pop when you let off the throttle. The popping is from one cylinder not running at idle and pumping unburnt gas into the exhaust.
Clean em again and don't miss any of the tiny holes.
Run the idle mixture screws all the way in and start out backing them off 1 1/2 turns. The cheap way is to run them out till you get popping when you roll the throttle shut and then back in till the popping stops.
If you don't have vacuum gauges or carb sticks, you can sync the carbs roughly by feeling the pipes when you start up and finding which cylinder/s aren't running. It's easier having the gauges.
 
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