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Jetting problems

Mcgyver

Mcgyver
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Hi guys my1977 CB750F chopper has been undergoing some mods lately and I figure I might as well go all out to make her run better . I cut up the 4-into-1 and made it a 2-into-2 the filter box has been removed and 4 pod filters installed . just had a brand new 3 angle valve job ,guides, springs ,rockers and new cam installed .360 valve lift and 270 degree duration.I dont want to pay for expensive dyno so before I put the carbs back on I want to jet them .Has anyone here done this before? .What size jets should I use ? Thanks in advance Mac:)
 
you need to get 3+ sets of jets and just try and tune the carbs
from my experience pods make things hard to tune and power loss on the street.

There are just to many variables for the "you need this" answer
 
OK, I would run it with the jetting you have now. You need to have a baseline to judge from. Jetting is not set in stone as there are far to many variables. I have a hot 836 with ported head, bigger cam, 4 into 1 and pods in my chopper and I run 125 main jets. The way I get close on the main jets is to run it wide open and start to close the choke.......if it gets better than it is lean, if it runs worse than it is close or it is rich. You can do the same thing in middle throttle range with the choke. Go slow dont just slam the choke closed. I have been running pods on my 750s for years and have no problem tuning them, just keep an open mind when jetting because there is no should be.....your motor needs what it needs as far as jets. As surffly said you can get a couple of sizes and try them and note the difference.
 
I hear ya Dirtdigger. Once warmed up it seems to bog out at the start and I have to run it with the choke untill it gets really heated up at wich point its better but not as smooth as it could be .I appreciate the info man :thumbsup:
 
I agree... start with what you have and work your way bigger. I've jetting bikes and started by going too big and coming back closer to what it was to begin with. Maybe go one up one the pilots and one on the mains. Do them one at a time though, pilots first.
 
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