ninjette.org - View Single Post - Looking for Definitive Short Answer to Carb Setup for K&N R-0990 Pod Conversion

austinninjabill · January 17th, 2018, 11:59 AM

Thanks for the reply. Given your stable of bikes, you've got some experience certainly more than me -- I haven't had a motorcycle since 1977 and then it was a 250 Maico (sunburst head, coffin tank and a 4 speed).

So it pulls strong to the redline with a 108 jet? And the plugs look good (brown, not white)? Most folks say 110 minimum and some a 112 to avoid a lean condition.

Do you think your location (WI -- cooler weather) makes a difference?

And out of curiosity, where did you get the idea/advice for the two washers under the needle in the first place as that is not stock? I wonder who first came up with that adjustment?

Any idea what that does? Guessing it allows more fuel into the mix by raising the needle base, maybe that's why a 108 works for you. Perhaps the 110-112 needle guys aren't shimming the needle or not as much.

So maybe the theory/rule could be for main jets 112 with no shims, 110 with 1 shim, 108 with 2 shims? And for pilot jet, 38 with 2 shims, 40 with 1 shim, 42 with 2 shims?

January 17th, 2018, 11:59 AM	#3
austinninjabill ninjette.org member Name: Bill Location: Central Texas Join Date: Jan 2018 Motorcycle(s): 1992 250R Ninja Posts: 27	Thanks for the reply. Given your stable of bikes, you've got some experience certainly more than me -- I haven't had a motorcycle since 1977 and then it was a 250 Maico (sunburst head, coffin tank and a 4 speed). So it pulls strong to the redline with a 108 jet? And the plugs look good (brown, not white)? Most folks say 110 minimum and some a 112 to avoid a lean condition. Do you think your location (WI -- cooler weather) makes a difference? And out of curiosity, where did you get the idea/advice for the two washers under the needle in the first place as that is not stock? I wonder who first came up with that adjustment? Any idea what that does? Guessing it allows more fuel into the mix by raising the needle base, maybe that's why a 108 works for you. Perhaps the 110-112 needle guys aren't shimming the needle or not as much. So maybe the theory/rule could be for main jets 112 with no shims, 110 with 1 shim, 108 with 2 shims? And for pilot jet, 38 with 2 shims, 40 with 1 shim, 42 with 2 shims?