delche

I just got a new T-maxx 2.5 and so far i haven't been impressed with the engine. I have a quart and a half though it but i cannot get the idle to go down, the adjustment screw is as far in as it can go. It will keep jerking forward after i bring the truck to a stop. The temps have been hovering around 240 to 260 so its not running too hot. It was real bad when i first broke it in but after replacing the fuel lines, zip tying them and the exhaust coupler its gotten better. I think the fast idle is also affecting my ability to switch from forward to reverse, sometimes it doesn't want to engage.

Just for reference:
Broke in with traxxas topfuel 20% now running o'donnel racing 20%. I'm running it real rich and there is a visible smoke trail at idle and when on the move plus raw fuel is expelled form the exhaust.

MY QUESTION?

Should i try to seal up the carb and backplate or should i try calling traxxas first?

Thanks you guys.

Danju

i would seal the carb first. When i got my revo 3.3 and tested for airleaks, i found one just below the rubber dust boot of the LSN. and after that, i sealed up the whole carb, backplate, coupler, header, ETC...

if sealing up doesnt help, then i would just call traxxas.

hawk 2

You have to screw the idle out, not in. If you screw it in you are pushing the carb open.

delche

Sorry, i meant out, i have turned it counterclockwise as far as it can go.

Nitr0-is-Deadly

since its new and traxxas are very good at CS id say call them up first..they might send u a new motor [:-]

legbuh

How big is the idle gap? Thicker than a credit card? If so, adjust it so it is about the same as a CC in the thickest spot of the "arc".

If it won't close any further, you need to adjust the linkage on the carb so it WILL close all the way using the idle screw. Then adjust the idle again from there and retune. Adusting can sometimes be done by rotating the carb, or also the black plastic piece that hooks to the carb can also be screwed in or out.

tommythecat

My Feedback: (2)

Have you checked your throttle linkages, throttle trim and the throws? If you servo is holding the carb open the idle stop screw adjustments will have no affect.

delche

i think its an airleak problem. i have the carb practically closed. Plus the engine is making a ton of power like its running lean. i richen the hsn to the point that the car dies at half throttle but a 1/8 turn lean causes it to gradually build up heat then the idle increases. i guess ill try traxxas support then probably move to an os .18tm