hey guys im having major throttle problems, I just picked this bike up for pretty cheap, it idles perfect and runs good heres my problem. the kid before me put on the two brothers black series onto the bike AND THATS IT NO JETTING NO NOTHING, yeah it sounds good but the bike cracks up between 1,500RPM ALL THE WAY TO 6,300RPM from 6,300 on it pulls hard and fine, and I also noticed that when backing off the throttle at high speeds it backfires and pops like a son of a bitch im very mechanically inclined so I can fix it myself, that is if I know whats wrong PLEASE HELP!!!!!

probably running a little lean, adjust idle mixture screws and maybe shim the needles.

see here:

https://www.ninjette.org/forums/showthread.php?t=10208&highlight=jetting+database

alot of info in these forums for carb repair.

search function actually works pretty good too.



also, buy an R6, they're fuel injected.

Is it a Two Brother's slip on or full exhaust?
Is the snorkel removed or the needles shimmed?
What king of air filter is installed, airbox or pods?
Have you checked the air filter or snorkel to see if they were clogged or dirty?

It may not be actual backfire, but exhaust popping which is somewhat normal for a slip on exhaust. One reason you hear it (popping) so well is because you have an empty tin can instead of a heavily baffled steel drum (stock exhaust).

The popping noise can be reduced by doing the kleen air delete mod, which stops the extra air entering into the already lean and hot exhaust. Most people who have installed slip on exhausts as well as some full exhaust have also shimmed the needles and removed the snorkel and kleen air system.

Also the popping that you hear on decel comes when you quickly and completely close the throttle (from WOT), doing so causes a lean condition. Ease the throttle closed.

its just a slip on, I want to remove the snorkel just don't know where it is, it does not have the shim fiz done to it either, im thinking of doing the needle shims (washers) today and would also like to take off the snorkel, so any help is greatly appreciated also stock airbox, so the poping I was told the same thing by a dealer so thanks for that but I want an honest opinion on what needs to be done because the dealer was saying its gunna cost me 800 to fix it and being a home mechanic I cant morally pay that whne I can do the work

Start here
Directory of all 250R DIY threads on Ninjette.org/ Carburetor and Jetting (https://www.ninjette.org/forums/showthread.php?t=5586) and forget what the dealer told you.

Under the seat. Remove the battery cover. Remove the battery. Remove the battery holder. See snorkel. Rip it off

its just a slip on, I want to remove the snorkel just don't know where it is, it does not have the shim fiz done to it either, im thinking of doing the needle shims (washers) today and would also like to take off the snorkel, so any help is greatly appreciated also stock airbox, so the poping I was told the same thing by a dealer so thanks for that but I want an honest opinion on what needs to be done because the dealer was saying its gunna cost me 800 to fix it and being a home mechanic I cant morally pay that whne I can do the work

800?!?! :eek: To shim the needles and pull the snorkel will cost you only the price of the washers.

Under the seat. Remove the battery cover. Remove the battery. Remove the battery holder. See snorkel. Rip it off

That seems like a lot more work than it needs to be. I just removed the side panel and airbox cover and yanked it out with some leverage of a screwdriver.

Hmm. Dunno. I guess whatever way is easier for OP .....

p.s I have many bikes and an R6 will NEVER sit in my garage unless im dead or simply want a piece of ****, I HATE yamajunk I have 2 more gsxr 600's one 2006 and one 2007that run circles around yeamha's R1 so that's out of the question and second this bike was bought for my girlfriend!!!!

probably running a little lean, adjust idle mixture screws and maybe shim the needles.

see here:

https://www.ninjette.org/forums/showthread.php?t=10208&highlight=jetting+database

alot of info in these forums for carb repair.

search function actually works pretty good too.



also, buy an R6, they're fuel injected.

I appreciate all the help, how do I remove the kleen air system or what have you, also how do I remove the snorkel, and any pictures will help thanks for all the info ~mike

Is it a Two Brother's slip on or full exhaust?
Is the snorkel removed or the needles shimmed?
What king of air filter is installed, airbox or pods?
Have you checked the air filter or snorkel to see if they were clogged or dirty?

It may not be actual backfire, but exhaust popping which is somewhat normal for a slip on exhaust. One reason you hear it (popping) so well is because you have an empty tin can instead of a heavily baffled steel drum (stock exhaust).

The popping noise can be reduced by doing the kleen air delete mod, which stops the extra air entering into the already lean and hot exhaust. Most people who have installed slip on exhausts as well as some full exhaust have also shimmed the needles and removed the snorkel and kleen air system.

Also the popping that you hear on decel comes when you quickly and completely close the throttle (from WOT), doing so causes a lean condition. Ease the throttle closed.

I appreciate all the help, how do I remove the kleen air system or what have you, also how do I remove the snorkel, and any pictures will help thanks for all the info ~mike

Check out the DIY directory (https://www.ninjette.org/forums/showthread.php?t=5586)
Removing snorkel (https://www.ninjette.org/forums/showthread.php?t=10090)
Removing kleen air (https://www.ninjette.org/forums/showthread.php?t=9948)