Box Stock

Jetting question please help!!!

J

jake45

New member
what jet should i be running on my predator 212 with no restrictor plate. i have a 140 e tube in it with a 36 main jet but after reaming out the plastic spacer between the carb and head there is too much air getting in and the motor bogs out when i give it gas. Should i be running a 40 main jet or bigger? At this point i am about to just by the spacer for 3 bucks and leave it the way it was but i really want to see how much this helps if i can get it jetted properly without buying 4 different jetts to test.
 
Not sure never messed with a predator carb but the way he explaines it to me sounds like the pilot jet is to small now that he opened up the size of the intake and it's getting more air
 
Sorry if I sound stupid but what is the pilot jet and where is it located. Also what size do u think I should get because I probably have the stock one in unless it's the same thing as the etube
 
That ? Would be better asked in the predator section i cant answer that cause i have never seen a carb off a predator
 
the low speed or pilot jet is in the bottom of the black plastic plug below the big plastic idle screw. ream it out to .022-.025 that's your problem you are starving it out on the low end so it can't get to the top side
 
With a stock air cleaner Idle jet .024 Main jet .032 stock e-tube with the stock air cleane,r sounds like you are too rich. Let the sparkplug tell you!
 
speedwaydesign said:
With a stock air cleaner Idle jet .024 Main jet .032 stock e-tube with the stock air cleane,r sounds like you are too rich. Let the sparkplug tell you!
Click to expand...

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.
 
jake17j said:
the low speed or pilot jet is in the bottom of the black plastic plug below the big plastic idle screw. ream it out to .022-.025 that's your problem you are starving it out on the low end so it can't get to the top side
Click to expand...

Agreed X-2..on this being the lowside jet, but not for sure if its not enough fuel or maybe to much. jmo
 
if your using a 36 main jet and 140 etube with the stock airbox, thats your problem. You dont need as big of a main jet with the 140 etube as you would with the stock etube. try a 30 main jet and see if it fixes your problem. I would also reccomend going with a bigger low speed jet since you bored out the carb spacer. your getting more air into the engine with the spacer bored out, so you need to compensate with more fuel, but 36 main is too much fuel.
 
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.
 
Weddle Racing said:
if your using a 36 main jet and 140 etube with the stock airbox, thats your problem. You dont need as big of a main jet with the 140 etube as you would with the stock etube. try a 30 main jet and see if it fixes your problem.
Click to expand...
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)
 
You must log in or register to reply here.
Back
Top