Jetting question please help!!!

[dilligas racing]

You can not cut out the stock
plastic piece it has nothing to do with the jetting im running a 9rpm motor with the stock plastic piece

 

[rookieracer75]

Be sure you haven't reamed out the plastic insulator to the point it is pulling air from the vent channel. If you go to far, you won't be able to get a good seal between the vent channel in the spacer and the venturi. I have seen this happen before and it will cause the exact problems you described.

we had this same problem. reamed out a new insulator not so fix and fixed problem.

 

[flattop1]

that's a decrease of 30.5%. Wouldn't that be a little excessive? Can there be that much difference between e-tubes? Just trying to learn. LOL

Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.(Al Nunley)

Doubt the e tube has that much difference, the biggest thing would be the stock air box: vs a racing type air filter and adapter.
Much like running with the choke on.

 

[sledge]

I put a "Holy Moses" blueprinted (.615" bore .022" lo/.039" hi) jetted clone carb on a stock predator once without the foam in the airbox and it was totally too much top end fuel, it would idle ok, but bogs when you opened the throttle full, if you opened it slowly it would run till valves floated, same carb runs prefect on one of my blueprinted clones with the CL-3 cam and 10.8 springs (turns 6970 with ease, on a near flat 1/5 mi. clay track pulling #360 clone 15/66 gearing with 34" T3 maxxis rr). As old as this thread is, I'm sure you've found and resolved your jetting problem.

 

[FOMOGO]

Kinda what I thought to, because I think the venturi in a predator carb is smaller than a clone....but not for sure on the 140 e-tube.

I just measured the carb venture on my Predator Hemi last night. It was .615. Isnt that what the clones measure? I think the throttle bore was .750. I was more interested in the venture size...