car-wris

I have run into a bit of a problem starting the car. I have to play with the needle to get it started. Once started the wheels spin as if the trigger is at full throttle. Again I play with the needle to get it to idle. When I get it to idle the car stalls. I have to go through this entire process again. When I get the car to keep running it moves slow. I try to adjust the needle again and the car moves on its own but I get the top speed back. After a couple of passes the car will stall if I hit the brakes too long. Could anyone help me in my time of need. Thanx

new92

Sounds like you need to adjust your idle screw. It has been a long time since I have tuned my RS4 though...bought a XXX-NT and havent looked back yet lol.

mtx3racer

you need to adjust all your needles. Move your idle 1/4 in, high speed 1/8 in and low end 1/8 in. Eventually i would save up for a temp gun if you don't have one.

alucard13

I don't think the rs4 rtr 3 has a low end.

car-wris

there is a screw on the carb that looks like it has a spring on it. Could that be the low end needle. It is on the other side of the air cleaner. Also, the needle that I have to adjust is the one that the fuel line is connected to. Thanx for the help.

alucard13

The screw with the spring is the idle stop screw. If your wheels spin without touching the trigger that means one of two things. The carb is open to much during idle OR the idle is set to high. Usually its the first one. If you screw the screw counter clockwise (i beleive) and if you have the radio on push the brakes. the more you turn counter clockwise the more the screw will let the carb go back, eventually so much that when you push the brakes it will close the hole. what you want to do is adjust your idle stop screw so that there is only a 1mm opening in the barrel of the carb when the brakes are fully applied and during idle. turning the screw counter clockwise makes the screw hold the barrel while also raising the idle higher.

The needle that attaches to the fuel line is your high end needle. Clockwise will lean it out and counter-clockwise will richen it out. Just remember, leaner is faster, but makes the engine hotter which is not good. you want to keep it around 250 degrees with that engine. I once had an rs4 rtr3 and i called hpi and they told me that engine can go to 280-290, but i wouldnt do it.

EdwardN

iTrader: (1)

If it is .15 FE stock engine-it doesn't have low end needle. there is only top end needle. I recomend you get rid of that original carb and put something different with two needles and all your problem will go away right on the spot. As long as you have original carb you will be never able to run that car dependbly-carb there is totaly sucks (sorry to say it).
Yes, 15 FE can run at 280-290 deg-we did it for purpose it was handeling 5 tanks with no damage at all. I still have that engine in good condition, as sample how to don't do the engines. LOL

DraKhen99

Top Gun, do you have any experience with the HPI 12R SC bump-start engine?

I have one in my RS4, and the sucker loves, and I mean LOVES, running at an average of 250 - 275 degrees [temps taken from around the head, and roughly averaged]. I have the Raytek MT4 temp gun, and the center of the head where the glow plug is, reads about 220. Different parts of the head read anywhere from 190 to 290, all while the center reads 220.

What is your technique in using the temp gun to gather temperature data?