250R Carb Tweaking

[Flyingw]

Guys, I have given R Force One a makeover and refresh so it can be sold. I already have a buyer for it and it will be leaving in the next couple of days. Before I tore it apart, it ran beautifully but now it has a very slight blubber at full throttle and I mean very slight. Its a TRX carb running a CT pipe with a 145 slow and 160 main. I have messed with the air screw but its still blubbering. Its been a while since I messed with 2 stroke jetting but isn't the blubbering a sign of being too fat on the main? It runs very good through the throttle range except for the blubbering. It start on the second kick.

How would you deal with a slight blubbering? Lean it down perhaps to a 158 main?

Here she is in 08 when I originally built it and after. Now everything is powder coated. Everything was refreshed or rebuilt front to back, top to bottom. Kinda hate to sell it now!!!!!!!!

[atc007]

156 or 158 Main. Also keeping in mind it will be colder out here when it gets here..Might be spot on ...

[Flyingw]

One other thing. I have oil coming out of the overflow. Just a few drips but this is telling me the float height is too high. After sitting all night, the oil is partially separating from the fuel and it sits on top of the fuel right at the end of the overflow tube. I thought it was tranny fluid at first but now I know otherwise. My confusion is..... the book says the float height is 16mm. I don't have a float height gage but I have digital calipers. The book is vague on where to take this measurement from. Can you guys shed light on where to take the measurement from point to point.

[Dirtcrasher]

Blubbering is usually rich. Should be nice and crisp.

If anyone can do it, it's you my friend!

[Bren_downe]

http://www.3wheelerworld.com/showthr...Jetting-Theory
It's a read, but well worth it. Blubbering is usually rich. Check your plug and do your plug chops.

[fire1]

From the trx board

[Bren_downe]

"With the float bowl off of your carb, hold the carb upside down. The measurement is taken from the gasket surface of the carb body, to the bottom of the center of the float."- copied from AF.com
Damnit fire1 you beat me to it

[RIDE-RED 250r]

Flyingw: Have a gander at this link. http://www.pjmotorsports.com/jetting-tuning.html

Step #1 in carb tuning is proper float height adjustment procedure along with float height specs for the different Keihin carbs.

Just remember, measure when the tab on the float just touches the spring loaded plunger on the needle, not depressing it.

[fire1]

Is that the same plug you had in there when it would start and you said it was wet. If so try a fresh plug

[Flyingw]

Beautiful guys. This is what I've been looking for. I dropped the main to a 158 and got the float adjusted. No more blubbering!!!! Thanks guys.

[RIDE-RED 250r]

Braap on brother!