I Have a 2008 TTR 230 and the stock jetting absolutly sucks, it constantly pops out the exhaust and sometimes fully backfires a loud boom (only happened 2 times) but now i have purchased a FMF PowerCore IV exhaust and now am looking for a jet kit on ebay since i cannot find any on known dirtbike websites (motosport, Rocky mtn, etc) I Have found 1 jet kit specifically for the 2008 TTR 230 and it has the option to call and get it custom ordered for your bike. But before i fork out 50 bucks for that i want to know what  jettings i should get/look for. Please dont just reply witha  copied and pasted link, i need actual helpful information for the TTR 230.

I would find out what the stock sizes are, either by removing yours or looking in the service manual. Then I would get the next few sizes up (every other digit ex. 138, 140, 142) for the pilot and main. If your needle doesn't have clip positions then I guess the kit wouldn't be too much of a waste of money cause it'll come with a new needle that will have clip positions and probably a different profile on the business end, but if it does, I would just buy the jets individually.

Oh, don't forget to get a less restrictive air filter and take the cover off under the seat, this will change your jetting too

Edited by goosey, 16 April 2012 - 05:55 AM.

The work has already been done for you. Look in the TTR stickies.

Replace the stock 35 pilot with a 38. It has a Yamaha part number, and is easy to find. Put a 130 main in to replace the stock 125. Open up the top of the airbox. Turn your fuel screw out to 2.0 turns. It will run like a new bike for less than $15.

Leardriver, on 16 April 2012 - 08:38 AM, said:

Where do you find those jets? Yamaha used a carb called TK(Teikei) and does not carry any jets other than the  factory sizes.

Here's what I found doing a simple google search:

http://motors.shop.e...nkw=230 jet kit

http://www.thumperta...ts/page__st__20