I just bought a 97 cbr600 f3. The ******* I bought it from cut the entire top half of the airbox off and put a drop in k&n. The thing bogs down like crazy when you gun the throttle. I have to ease on the throttle slowly or it studders like its choking. I cant rip it.

I took the carbs off to see what its got in there for jets. I opened up one of the end bowls and the main jet is a 140. What is stock size? do you think 140 is too big or too small? I am no good at jetting it took me a month to get my quad jetted right. What do i need to throw in there? is the 140 too big or too small? My buddy runs 130s in his katana with pipe and filter.
I also have a D&D pipe on there.
What size jets?

 

I just found a stock box on ebay from a 98 f3, will it fit my 97? Im about to buy it and put the top back on

 

98 & 97 will be interchangeable tmk. The differences come into play 95 / 96 vs 97 / 98.

Stock jet sizes on the 97 / 98 are 138 on 1 & 4, 140 on 2 & 3. Sounds like the PO made some 'adjustments' for his 'mods' (aka improvised for his improvisations) if you found 140s on an outer carb. Also means the inner carbs are likely larger. Might have to take her back to stock just to get a known baseline.

Try getting a stock airbox on her and verify all your air hose routings. Clean the carbs if necessary and see how she runs with the current jetting. An aftermarket exhaust + k&n filter might need larger jets since they increase air flow. But half an airbox will definitely be screwing with performance.

 

actually stock jetting is 135 on 1 and 4, then 138 on 2 and 3....they have bigger size jets in the middle to help with cooling

 

Weird. Haynes says 138 / 140 for the 97 & 98. I know 135 / 138 on the 95 & 96. Checked the pdf of the service manual and it agrees with you.

So go with Honda933's #s

 

Alright I just ordered an airbox off ebay. Ill clean the carbs and throw that on and see what happens. What is the reccommended jet size for my setup:

K&N drop in (with full airbox soon to be) and a D&D pipe.

What should be in there for jets?

 

I would start with stock jets, when i bought my bike in Vegas it ran great with 140 on 1&4 and 142.5 on 2&3. got it back to Colorado and it blew flames like it was its damn job. cleaned the carbs, put in 140/138 and re-tuned/ sync'd them, ran better but recently dropped down to 138 and 135's finally and its perfect now. I have a Cali model with a K&N, ignition advancer, and Vance and Hines SSR2 exhaust. Good luck

 

essentially you will be moving more air.....so 138's on the 1 and 4 cylinder and 140's on the two and 3 will be good....thats what im runnin

 

You have to take alot of things in to get the jetting correct. My jets are 145 on all of them. I used a Factory Pro Race kit but thats not all. 4 degree adjustable advance (Factory Pro), K&N filter, and a Micron exhaust just to name a few.

 

more air means i need bigger jets right? so if stock are 135 1&4 and there's 140s on 1&4 5 sizes over do you think thats too big? where can i order jets from? the dyno jet kits are crazy expensive I bought jets for my quad for a couple dollars each