CSC TT250 overheating?

[SirStogy]

Hello all,

I'm new here. I've used the site to find some good info in the past but now have a question I cant seem to find an answer to. I have a pretty new TT250 that rides nice and smooth but after about 5 miles, regardless of the weather, the clutch gets chunky and it lags when I take off from a dead start. Sort of jumpy. It's very noticeable and the only thing I can think of is that it is over heating quickly. But whether it's the hot sun or 3am rain, it will always do it towards the end of my ride. I use the proper gasoline, have changed and tested thicker oils, I cant figure it out and the mechanic didnt seem to want to investigate too much (he was a bigger fella and didnt want to ride too far). Any help y'all can give would be really appreciated.

[J4Fun]

My thoughts, valve adjustments first, and are you using the proper oil for the clutch?

[SirStogy]

I have adjusted the valves several time and all seems well with them. I have also used the recommended oil but have since switched to 10w40 I believe it is. I could be recalling incorrectly tho.

[Thumper]

What you are describing could be lean jetting. "jumpy" and lags off the start, and running hot are all reasonable explained by lean jetting.

Have you drilled out the airscrew? What jets are in there. It is pretty common for OEM jetting to be lean for emissions reasons.

[SirStogy]

I bought a jet with a bigger hole and installed it but that caused it to jerk pretty violently and shut off at times. I changed it back to stock, though I'm not sure what size the stock one is.
I would take it to another shop for unfortunately the mechanics don't want to touch it.

[Thumper]

There are numbers on jets. Get a pair of reading glasses or a magnefying glass. You need to know the actual numbers.

[SirStogy]

So it looks like the stock is #108 and I tried the #112 and it didnt run right. Would raising that ring on the needle in the carb maybe help?

[ughmas]

I experienced a bit of this when my TT was new, especially when it got hot on tough trails at low speed.- After breaking it in a bit more and switching to synthetic oil the clutch grabbing/chatter went away.also did the aftermarket exhaust and the CSC jet kit at the time, as they are jetted lean to start with which will increase engine heat.



I know thats not super helpful but try to put some more higher speed/open road miles on it, and then change to full synthetic

[Thumper]

If the air screw has a cap covering it, you need to drill that out. Try adjusting the air screw. If it is between the head and slide barrel, it is a fuel screw, And opening ( counterclockwise) makes it richer. If it is between the slide tower and the air box, it's an airscrew, and opening it leans it out.

Do you have 4 or 5 options on the needle height, or is it a single position needle? You can shim the needle to lift it (more fuel) in the midrange (richer).

[Thumper]

Look at post #5 in the Templar resource guide for instructions on needle shim. It's in this dual sport/Enduro forum as a sticky.

[SirStogy]

What altitude are you at and what jet did you go with? Did you just replace the main jet or did you also change the idle scew and adjust the needle depth? I'm in CA at sea level.

[SirStogy]

I believe it's an air mixture screw at the side. For the butterfly valve. The needle has several positions so I'll give moving it one down a try.

[SirStogy]

In theory, would opening the choke a tiny bit help get some more fuel, if that's the issue? Not that it should be a permanent thing.