Topic: CB500K2 running problems, help! at wits end!!!

[northtexan89]

Ok here is what I am working with. I bought the bike at a trailer park for $350 and only the engine ran and it slightly drove

1973 Honda CB500four SOHC
original CB500 Keihin carbs with cheap shorty pods (heavily oiled)
4 to 1 exhaust with muffler and no baffle
swapped out main jets from 100 to 115
raised needle from 4th clip to 5th clip
rebuild and cleaned carbs too many times to count
slow jets are at 40, thinking i may need to go to 42 or 44
mixture screws are a full turn out from fully seated
new o rings and gaskets all around carbs
new intake boots
float height at 22mm as per spec.

so there are absolutely no air leaks or gas leaks
I HAVE NOT checked compression in cylinders YET.
all spark plug wire spark. When I first pulled them they were super sooty, but i regapped them to .065mm, I do not have a tool to get 2 and 3 out of the block right now.

The symptoms:
cold start, starts up first kick and get with starter. idles great for about 5 minutes and then starts to die off slowly until it just dies. harder to start after that and when driving it the idle hangs really bad, not even a blip will cut it back down. there is power loss on the low end(idle to 1/4 throttle), slightly better midrange and strong pull on high end( full throttle). it runs really hot about just 5-10 minutes of use. this engine has been gone through before me and I'm positive it has been used to race with, might be bored out, hard to tell. when it idles it sounds like it is misfiring every now and then. could it be my coils? new spark plugs? any ideas or help at this point would be great!!!! also i have no acces toa compression tester and am very low at cash at this point :/

[northtexan89]

anyone?

[bollingball]

Ok here is what I am working with. I bought the bike at a trailer park for $350 and only the engine ran and it slightly drove

1973 Honda CB500four SOHC
original CB500 Keihin carbs with cheap shorty pods (heavily oiled)
4 to 1 exhaust with muffler and no baffle
swapped out main jets from 100 to 115
raised needle from 4th clip to 5th clip
rebuild and cleaned carbs too many times to count
slow jets are at 40, thinking i may need to go to 42 or 44
mixture screws are a full turn out from fully seated
new o rings and gaskets all around carbs
new intake boots
float height at 22mm as per spec.

so there are absolutely no air leaks or gas leaks
I HAVE NOT checked compression in cylinders YET.
all spark plug wire spark. When I first pulled them they were super sooty, but i regapped them to .065mm, I do not have a tool to get 2 and 3 out of the block right now.

The symptoms:
cold start, starts up first kick and get with starter. idles great for about 5 minutes and then starts to die off slowly until it just dies. harder to start after that and when driving it the idle hangs really bad, not even a blip will cut it back down. there is power loss on the low end(idle to 1/4 throttle), slightly better midrange and strong pull on high end( full throttle). it runs really hot about just 5-10 minutes of use. this engine has been gone through before me and I'm positive it has been used to race with, might be bored out, hard to tell. when it idles it sounds like it is misfiring every now and then. could it be my coils? new spark plugs? any ideas or help at this point would be great!!!! also i have no acces toa compression tester and am very low at cash at this point :/

Not much you can do until you get a plug wrench. With the mods to the intake and exh. You will get a lot of practice swapping jets I can't help on that I keep or change all my bikes stock. Make sure you keep good air flow on the motor (fan or two) Try leaving the gas cap open and see if that stops the dyeing after 5 to 10 minutes could be a plugged vent in the gas cap. There are a lot of pod people that will give you some set up help.
good luck
Ken