revo7617

Hi, I want to know how to tune my engine, i have a revo and a OS .18TM with only 15 tanks. At break in the engine looks powerful, but after that, an stock TRX 2.5 can beat it.

I need help with tunnig, (Im intermediate in nitro RC), i been tunning my TRX, but with this, i cant find the way to make it go fast. A lot of forums said that this engine make wheelies, but in my case wont.

Plese, help me to find the stock settings, and then start all over again, (how many turns in every needle) because the instruction manual dont have all the settings im looking for

Im using Dynamite 20%

PS. What is the average temperature in this engine??

ThermalRD

Our engine settings wont help you at all. Engine settings vary to a HUGE degree based on the weather where you run the engine. Dynamite 20%? Is that the blue thunder fuel? Have you been tuning the engine for performance? or tuning according to how much smoke you see? Your running temps should be consistant around 230-250 with that engine. At 230 it screams... At 250 is big block fast... And yes, wheelies are no problem. Also, make sure your carb is opening all the way. I thought i was chasing a tune on my 18Tm forever. Realized it was the carb not opening all the way. Which was caused by the throttle arm on the revo not being positioned correctly, in the OUTER hole.

binaryterror

I found my stock TM had way too rich settings during break in and was powerless really. Then I tried leaning everything (not the mid) and it got cooler and ran way better. You might be overly rich...

revo7617

Thanks guys, Yes Dynamite is BLUE THUNDER 20%. I know maybe your tunning wont be the best fo me, but i tried all and i want to have some inputs of other guys.
Im gonna check the carb. and the throtle arm!
My problem is that my engine is getting the 300F, but if i run it richer, is powerless and sluglish.

Im tunning for performance, what is the average number of turns in the HSN for the .18TM?

ThermalRD

At 300 degrees, something is wrong. Over rich will NOT get you 300 degrees. You are tuned way off, or have an air leak. Check the backplate screws, the head screws, and make sure your carb nut is still in place. At 300 you would actually start to lose power. How hot is it outside when you are running?

revo7617

I know!!! 300 is way off!!! obviously im loosing power, but if i set it richer is slugglish or powerless.
Im runnig a Pullstart, im gonna check the srews, how about a problem in the manifold, (maybe the spring doesnt pull to much the manifold to the back of the engine)

What else could be?

The temp is not to hot or cold outside (23 Celcius - dont know in Farenhait.)

revo7617

Since day one, at break-in, the temp went to 280F

ThermalRD

No, the manifold would not cause that much heat. You would be looking for an air leak at an area that would be entering the engine, not at the exiting exhaust port. You would be looking for loose backplate screws. Not pullstart screws. Backplate screws that need to be checked when the pullstart is removed. Cooling head screws. And loose glo plugs, as well as the carb bolt. And just as i've mentioned, make sure your carb is opening all the way. If you are trying to tune your engine for performance, with a carb that wont open. You'll be leaning it out looking for more RPM's. You will NEVER find it if the carb doesnt open all the way, and yes it will cause overheating. I did the same thing on my 18Tm, and came real close to buying a new motor. Found out the carb was not opening up all the way, on a consistant basis. This is a very common error on a Revo when someone drops a new motor in it. That throttle arm really needs to be tweaked to work properly. Lets us know what you find when you go over all that.

ITZBOB

I just had the exact same problem with my motor. Ended up being a significant air leak in the motor. My leak ended up being the front bearing. It must have been that way from the factory because I only have 15 tanmks through it. Is your truck idling real high after a high speed run only to settle down after 2 seconds?

Try this site, it helped me find my air leak in 10 seconds.

http://www.*********.org/engine-tuning.htm

revo7617

Thanks, im gonna check for air leak. But im guessing maybe the problem is in the throtle link, as ThermalRD wrote. Maybe Im trying to get all the RPMS with a half throtle. As soon as I check it, ill let you know!! thanks both!

I also have 15 tanks through it, but doesnt idle high after High Speed passes. but Ill check that too.

nicholsm04

My Feedback: (-1)

My OS.18 runs about 250-270 in my revo. I have it tuned slightly rich though, I dont want to risk doing damage by leaning it too much. But it is running excellent, wheelies are easy, and this little .18 HAULS! I have it out right now, dont want to run it in the winter.

revo7617

Hi guys, can someone place some pics of the correct position of the Throttle arm??