RCU Forums - engine issues

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i have a nitro sport w/ pro.15. today i was driving it around and it startes to hesitate when accellerating mildly after about 1/3 of a tank. on the next tank it was hard to start and then wouldnt rev out for about 1/4 tank. then in just an instant it seemed fine again for about 1/2 tank. finally it started hesitating when accellerating till it ran out of fuel and i gave up for the day. any ideas what could be causing this? motor compression seems fine, carby well tuned, not running lean either. thanks for any help.

RE: engine issues

is there smoke coming out of the muffler? if so then it is too rich and that's what is causing the engine stalls and then you should retune everything

RE: engine issues

actually lemme rephrase is there lots of smoke coming out if so then too rich lean out about 1/3 of a turn

RE: engine issues

Quote:

ORIGINAL: simonr23

i have a nitro sport w/ pro.15. today i was driving it around and it startes to hesitate when accellerating mildly after about 1/3 of a tank. on the next tank it was hard to start and then wouldnt rev out for about 1/4 tank. then in just an instant it seemed fine again for about 1/2 tank. finally it started hesitating when accellerating till it ran out of fuel and i gave up for the day. any ideas what could be causing this? motor compression seems fine, carby well tuned, not running lean either. thanks for any help.

The inconsistencies you describe are a common symptom of an air-leak. Replace all lines first off. Blow through the new pressure line while keeping the line that feeds the carb sealed off, that way you can make sure that the tank isn't leaking. Also ckeck to make sure your cooling head and carb neck are tight. If this still does not fix it, you will have to pull the engine and seal the carb neck and back-plate with some type of gasket sealer like RTV (you can get it for 2-3 bucks at any auto parts store)...

RE: engine issues

thanks for the help guys. firstly, yes there is a little smoke, but only as much as there should be imo. the jetting has been very simple and luckily not too dependant on weather and all that, so its normally runs excellently. today i bought new fuel tubing, and a new tank seal too. the carby is VERY tight in its crankcase sleeve, havent yet checked the cooling head yet. tomorrow(raining today) ill put the new bits on and check the motor.

oh and another, hopefully unrelated thing. i still use traxxas' ez-start for cranking, not the glow plug tho, and every 4th or 5th start i have to take out the one way bearing and clean it of fuel. slips alot. is this common. it seems if the fuel is coming through from the bearing, not from outside the ez-start casing. again thanks for your help guys.