2024 TT250 need stock pilot jet.

[Sdmfjon]

Hello,

I bought a new tt250 and the jet kit from CSC. However my carb came with a 35 / 102 instead of the 38 / 108.

Long story short. Bike is completely stock with emissions delete and capped off. The 40 pilot is to rich ( runs with fuel screw shut, idles poorly. the 35 jet is too lean (I have to have the fuel screw about 4 1/2 - 5 turns out to idle smoothly but am having lean problems.) Also my idle screw is physically loose with this many turns out.

Bike has 200 miles, valves adjusted twice, oil changed twice, using D8EA spark plug., emissions deleted and verified no vacuum leaks.

I believe the 38 pilot jet would solve most of not all the issues I'm having.

I have contacted CSC and they do not have 38 jets nor can I find the one online.

I think I am left with two choices.

Find a 38 from a member on this forum who will sell and ship me the pilot jet.
Or
Swap the nibbi pe28fl and deal with the fitment issues.

Id rather find a 38 jet.

Need help from the community, thank you all in advance.

[krat]

There is a third choice.

Measure the exact diameter of your pilot jet and order a set of micro-drill bits from Ebay.

https://www.ebay.com/itm/28582842490...Bk9SR7Dd8P6hZA

There will be a stepped set of bits in the kit and they are cheaper than worrying over the problem you are having now on any carb, ever again.

Start with the bit that passes through the jet and progressively ream out the hole until you achieve the performance you desire.

This works for main jets as well as pilot jets.

Just don't over do it, there is no putting back a bit of metal. Better to stop a bit short.

[dirtbkr188]

...and a fourth option


you could post up a picture of the #35 pilot jet that you have, along with the dimensions of it, as shown in the pic below. That gives us an idea of what you're working with, and make it easier to see if someone has a #38 that matches.

[Sdmfjon]

The Keima TT250 pilot jet measures about 35.10mm long, 5.86mm thread width, width of head about 5.05mm.

In a different thread I read something about these pilot jets being proprietary to Keima.

[dirtbkr188]

Thank you for posting the pics and specs, that is a unique pilot jet, I've never seen one like that at all.

[red2003]

Just buy an Amazon PZ30 and Keihin Jet kit. Direct replacement, and for under $30 you'll be all set. These are the Keihin style jets that fit: https://www.amazon.com/YAMAKATO-Afte...s%2C120&sr=8-4

[ProDigit]

Search Amazon or AliExpress for oko Mikuni pilot jet kit

[ProDigit]

Originally Posted by krat

There is a third choice.

Measure the exact diameter of your pilot jet and order a set of micro-drill bits from Ebay.

https://www.ebay.com/itm/28582842490...Bk9SR7Dd8P6hZA

There will be a stepped set of bits in the kit and they are cheaper than worrying over the problem you are having now on any carb, ever again.

Start with the bit that passes through the jet and progressively ream out the hole until you achieve the performance you desire.

This works for main jets as well as pilot jets.

Just don't over do it, there is no putting back a bit of metal. Better to stop a bit short.

Drilling jets out is mostly for main jets, the pilot jets have a two small opening, you'd have to find a drill the size of a hair.

[Sdmfjon]

I decided to buy a Nibbi pe28fl.

[red2003]

Originally Posted by Sdmfjon

I decided to buy a Nibbi pe28fl.

Be prepared for a very fussy tuning experience. The air screw on Nibbi's are fiddly, especially with a low compression engine. Small adjustments make BIG changes.

[Megadan]

I would have contacted CSC and gotten a new carb under warranty, assuming you are still under warranty. If it can idle with the mixture screw turned all the way in, something is wrong with the carb.