ntc3 rtr plus .15 overheating
 

i took the carb restrictor off and now the engine overheats after running powerfully. can anybody advise me with some good needle settings for the stocked .15 engine after the carb restrictor is removed. thanks.

mixture
 

You need to richen it up some .

Latemodel has the right answer. If the car ran great and then you removed the restrictor you have more air available to combust... if you don't richen it there is more air to the same fuel and you will be lean. Lean would make it hotter. Richen it up and you'll be fine (disclaimer... there are other things that would also make the engine run hot).

my .15 does that exact same thing. it ran fine for a while even after i took the restrictor out then all of the sudden it started over heating. i believe that my low end is set at 3 turns out, and my high end is set at 3 1/2 to 4 turns out and it still over heats. what else do you think could be wrong? thanks for the advice...

A broken clutch spring or the clutch is otherwise failing. An air leak. A bad bearing in the drive train,

There's a start for ya....

temp guage tuned (high speed) the damn thing keeping it under 285-the car screams now without overheating

i did the low speed tuning by ear

thank you for the advice. i am gonna look at those things tomorrow. where should i check for air leaks? ive only had this car for about a month and a half and the only thing i changed beofre it started over heating was the fuel line. im not sure if that could be the problem or not.

Air leaks are most commonly where the carb goes into the case and at the rear plate. Some RTV sealant helps.

I have occasionally had trouble with brand new fuel line. I have had an air leak in new line. Sometimes there is a different inside diameter to the tubing too.

when i first put the new ful line on, i thought that the inside diameter was a little smaller. i am gonna put some silicone under the carb like you said and put the old fuel line back on to see if that helps. thanks again for your help

alright bro--i tuned 3 ntc3's this weekend.

one of them would overheat alot-so bad you could not clog up the pipe hole to cut the engine off.

the air leak came from the high speed needle neck---all i did was tightened it (turn it clockwise so it sits snugged in the carb) and that stopped the leak - the BIG time air leak was gone!

another ntc3 had an air leak from where the pipe attaches to the side of the engine-basically the screws were loose and the gasket was trashed. we put a new gasket on and tightened the screws and no more air leak

after you fix the air leak-i reccommend you tune your car like this.

start the car--richen the high and low speed-----give it a couple full throttles

if it boggs right away as soon as you give full throttle then lean out the low speed-1/4 at a time--until it sounds right-then lean it another 1/8 turn

now for the highspeed-you need a temp guage (Duratrax $20 hobby store)-make sure its very rich--give it full throttle for 5 seconds then no throttle for 3 seconds-then full throttle for 5 seconds--now measure the temperature.

if its under 260 or 270--drive it hard for 20 seconds-then measure the temp again (right away-dont give it time to cool down)--if its over 285--richen it out 1/8--if its around 285 ish-then run it for about 30 seconds-if it stays around 285-you are tuned--if its too hot then richen it out 1/8-if the temp is around 260--lean it out 1/16 and keep testing

try it out and let me know--but this is what i did to get the tuning right on 3 ntc3's this past weekend-3 ntc's that kep overheating when we removed the carb restrictor