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Tc 250 setup

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I have a 14 tc 250 with scalvini exhaust kn airfilter and ported yamaha 38mm carb with quad wing.

The engine is completely stock, and i currently have the following carb setup

Pilot jet 42

Needle nedj 4th clip from the top

Main jet 170

Power jet blocked off

Slide #7

I was runnin with my friends and noticed a couple issues

1. When i brake hard the engine tends to die

2. When i go up and down hills i burn twice as much fuel vs wot level riding in the sand

3. In mid throttle position i feel the bike tryin to rev up but then stumble and do the same thing again.

4. When the power kicks in it goes like a rocket, but if i keep the revs towards the lower end of mid throttle she hesitates a little.

Do i adjust the power valve any?

Do i drop a needle size and activate the powerjet?

How to i modify the bowl so I have the same over fill tube as the ktm?

My next mod is the 9oz flywheel to ease the kick and give my like 4t bottom end power.

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Sounds like it needs a float adjustment.

Boy, when changing a carb, jetting can be a nightmare. Hopefully you can find someone who has the same set up.

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I would raise the clip position one notch. That should help smooth out the mid throttle stumble. Looks like you are running a Suzuki needle I know a lot of guys will recommend the NECJ. The NECJ was too lean for me and I had good luck with the NECW which is a step richer than the J. But I'd start with one clip leaner on the needle you have and it should help

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I swapped the overfill tube in the bowl. I am also goin to try a 40 powerjet and raise the clip one now and possibly one more if needed. If i cant get get it right i will swap the needle to a necw and turn off the powerjet.

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I did some yamaha searchin on jettin and what they did was

Pilot 48

Main jet 175

Powerjet 50

And nedj needle third clip down.

I am goin with the followin

Pilot 42

PJ 50

Main jet 170

Nedj 3rd groove down.

I at sea level and 45-75F

Will see how she performs tomorro on our trails

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Looks like i found the missin factor, the power jet really mellowed the hit and gave it a boost till the main jet kicked in.

May play with the needle and pj till i also get the range i want...

Did a nice full trip today and my tank did last 3hrs of ridin

Carried extra fuel just in case

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Yes i added a yamaha yz250 carb and bored out the back end to 39 mm then added a quad wing for more power.

The power jet helped me richen the mid section and mellow the punch when the exhaust valve opened up

Edited by Naf
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So in my mind i am thinking to drop the needle one more clip and reduce the powerjet to 45.

I ran around two hrs over the weekend and burned about a gallon of fuel. I was mainly in the lower side of the mid rpms with occasional wot to climb the sand ridges.

Later i will lower the main jet or install a rpm switch to turn on and off the power jet

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Just for information for others my current setup is as follows

pj 42

Needle Necw 3rd from the top

Mj 175

Powerjet 50

The bike has great wot pulls and is only limited to the rpm rev limiter.

Fuel consumption is good for a 2t

Fifth gear pulls from above idle are nice and smooth with no jerkin or sputterin

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