Wrong Jet Sizes?

[DanBarregarye]

I pulled my carbs for a good cleaning and noticed something peculiar. Carb 1 had a no.100 jet while the other 3 all had 105's. Aside from the fact that all the jets should be the same size, im fairly certain that my 1980 cb750f supersport should have 98's in the carbs. The bike is completely stock. What are some problems im going to run into with jets that are too big? Why would someone change the jet size on a stock bike? Lastly is this going to affect the number of pilot screw rotations? Thanks in advance
dan

 

[dirtdigger]

Different exhaust, different intake, different elevations all have effect on what the jetting needs to be. Thats not that much of a jet change anyway. As far as the two different size jets...who knows why they did that, maybe at one time it was on a dyno that measured each cylinders fuel ratio and found this is what was needed. It could also be from a person that had no ideal what they were doing. Just because a certain jet came stock doesn't mean it is right, most often bikes come lean from the factory to meet emissions standards and not necessarily to make them run good.

No main jet size should have no effect on pilot screw.

 

[FTS902]

Dirtdigger, ive seen your posts all over the forum. I just want to say i think you are fantastic.
Getting back on topic, is there a resource (thread) on this forum that explains the relations between the jets, exhaust, A/F and all that? Ive been having trouble finding good solid info on the subject.