1980 CB750F stock jet sizes and settings?

[Exponent]

Bought this bike with an aftermarket 4-1 on it already, the headers are nice so I will keep them and the muffler is ok for now but the bike won't idle on choke or rev very high after doing basic cleaning on carbs. I believe it runs lean currently and my theory is returning to stock settings on the carbs will produce a rich running bike.
Stock air box

 

[brettp]

If you have a stock aorbox, use stock jets. Doesn't matter what exhaust you have.

 

[Exponent]

If you have a stock aorbox, use stock jets. Doesn't matter what exhaust you have.

Do you know where to find some oem jets? I know I need 40 68 105, but I'm having a hard time finding a set

 

[brettp]

Try cb750supply or vintagecb750

 

[Exponent]

Try cb750supply or vintagecb750

Are the pilots on the vb42b press in?

 

[brettp]

There is one pressed in under the rubber stopper, i believe. But the pilot and main are screwed in. That is, if in thinking of the right carb!

 

[Exponent]

There is one pressed in under the rubber stopper, i believe. But the pilot and main are screwed in. That is, if in thinking of the right carb!

Does this help?

Took the rubber plugs out from the pilots, they're very brittle

 

[brettp]

Yeah, there is a pressed in jet under those plugs. I think the solution is to use an m4 tap, then screw a bolt in it to pull it out. But you need to be careful of how much tap you push into it. Do a search of this forum and you'll find it.

 

[Rampton]

I used a 1.5 ml easy out plenty of carb cleaner they all came out easy. Measure how far they are in before extraction. So the replacements are seated correctly

 

[Exponent]

I used a 1.5 ml easy out plenty of carb cleaner they all came out easy. Measure how far they are in before extraction. So the replacements are seated correctly

Is it possible to figure out the sizes without removing?

 

[brettp]

Don't think so. Have to see it to be sure