1979GreenMachine
CB750 Member
Hi all,
Just joined the group. I hope to find some helpful steps to getting my bike on the road.
I bought a '79 CB750K last year for $250 with 5K original miles. I have a total of $500 in it now. I have bought alot of new parts (carb kits, air cut-off valves, front brake cylinder, tank petcock, etc.) and still can't seem to get it running right.
I have took apart the carbs and cleaned each one meticulously at least 5 times. I'm almost out of ideas what the problem might be.
When I bought the bike it would only run a few min with the choke on (seemed like a carb problem), I then cleaned/rebuilt all of them with new stock parts. The original exhaust was all rusted out and needed replacing.
I replaced the original pipes with a used set from a '81 Honda CB750C which seem to be a good replacement.
I have not changed the jets in the carbs. The bike will start and run strong a few min (sometimes), but then it seems like it's getting too much fuel. The exhaust looks gray and smokey as if running with the choke on. The choke is not on. After running like this for about a min it eventually bogs down (even with the throttle wide open) and dies. Note: the mixture screws are all set at about 1.5 turns out.
Have been trying to figure this problem out for several months now. Someone help!
Just joined the group. I hope to find some helpful steps to getting my bike on the road.
I bought a '79 CB750K last year for $250 with 5K original miles. I have a total of $500 in it now. I have bought alot of new parts (carb kits, air cut-off valves, front brake cylinder, tank petcock, etc.) and still can't seem to get it running right.
I have took apart the carbs and cleaned each one meticulously at least 5 times. I'm almost out of ideas what the problem might be.
When I bought the bike it would only run a few min with the choke on (seemed like a carb problem), I then cleaned/rebuilt all of them with new stock parts. The original exhaust was all rusted out and needed replacing.
I replaced the original pipes with a used set from a '81 Honda CB750C which seem to be a good replacement.
I have not changed the jets in the carbs. The bike will start and run strong a few min (sometimes), but then it seems like it's getting too much fuel. The exhaust looks gray and smokey as if running with the choke on. The choke is not on. After running like this for about a min it eventually bogs down (even with the throttle wide open) and dies. Note: the mixture screws are all set at about 1.5 turns out.
Have been trying to figure this problem out for several months now. Someone help!
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