well my 96 cbr1000f has been in desperate need of some new jetting. it has yoshi pipes on it, and just sputters a little sometimes and has a hard time keeping a solid RPM, just bounces a lot. bike has good compression, vacuum, new plugs, new K&N air filter, and good fuel. i have cleaned the carbs, and also rebalanced them. i have a feeling that it is running a little lean because no matter how hard i ride it i still get ~50mpg.

so what kind of jet kit would i need? any idea on how much they cost? ive never been too savvy with the technical side of carbs, just mechanical. i was thinking maybe #135 jets and #45 pilots? does that sound about right?

thanks.

also is there a write up on this? i looked and cant find one. i have done some carbs before where you have to count the number of turns when you take the jet out so you put i back in the same, or do you just screw them all the way in?

also how bad will this affect fuel economy?

 

From my own research jetting carbs can be a difficult job. Altitude, exhaust, and air intake all take a part in jetting carbs, though I am sure there are some folks on here who have their cbr's jetted with your set up and it may help. But just swapping main jets and pilots may not help, you may need to shim your needle as well. I have found dynojet makes a good kit(used it on an old GS750) and are fairly easy to install. I believe they make a stage 1 jet kit for our bike. Good luck.

Also are you just bench syncing them or are you using a carbtune or similar?

Fuel mileage stock is around 40 mpg if memory serves me. I get 29-33 my bike is jetted, but for the life of me I cant remember the sizes. And our jets just get screwed in till tight.

If I get a chance this weekend I may pull one of my carbs apart and see what jets mine are and what not. I do have to put my new chain and sprokets in too.

 

Hey:

From where you live, unless Northern Western side 126-128 mains 130 max 40 stock slow should be fine, this should be plenty on normal premium fuel. You will need more fuel (bigger jets) if you use more than 10% gasohol. (Unless it is a Cali model)
What are your plug readings at full throttle, top gear, almost white is ok (like new) , with a slight tan if you can't do a WOT run.

Mileage may suffer, depends on gearing. 50 mpg is good expect less after jetting changes.

Jets tighten till very snug, do not overtighten, also install a fuel filter. if already have one make sure it is clean.

hope this helps.

good luck

Dub

 

Dam, I get ~ 35mpg with stock everything. Love to see 50.

 

Ok, I did some searching in my old posts, and found that my jets are #124 main jets and #40 pilot jets. Good luck!!

 

you know, i didnt even bother to check the fuel filter, ill change it out this weekend and see waht happens.

well, thats what scares me, it has got to be running lean

 

Have u done plug chops?