Toxik

I just bought an OS 18 TM for my Revo and was starting the breakin procedure that is used for the Traxxas 2.5R and am having some high temps. I'm was only half the way through the first tank when I decided to stop running and come inside. At one point the temps were 300 Deg. I never ran it more than 3 min, usually less and always let it cool to around 120 Deg. Once It got up to temp it would start to run eratically. I'm not sure if I was running too lean but there was lots of smoke and even some unburnt fuel coming out. Or is it normal to half higher temps during the breakin procedure?

I was tired of fighting high temps with the traxxas motor and from what I hear the OS motor was super dependable and ran at low 200's. Also the traxxas motor lasted 2 1/2 before it died. I don't want that to happen to this motor either.

Does anyone know what the needle settings are supposed to be cause I can't seem to find them?

I'm using the glow plug that came with the motor and a THS muffler.

flaminheli

You will usually notice higher temps during breakin that is because of high friction from a tight quench between the piston and cylinder, that is why you want to run rich during breakin. IMO

Toxik

I realize that it could be higher, but getting up to 300 deg in such a short time isn't normal is it? Has anyone else experienced this and if so do the temps stabilize?

nitro fanatic

the only thing i could recomend is to richen it up and how fast are you runing it during the break in

Toxik

I'm running 1/4 throttle for 2 secs for 2 min. It's not much at all.

With the Traxxas 2.5R, the hs needle was 4 1/4 to 4 1/2 turns but with the OS 18tm there is no info. From the factory it was 3 turns out so I went an extra 1/4 turn already but no difference.

Freezetron

Richen it even more, you do not want the temps to go over 220 while breaking in the TM or you will prematurely wear out the sleeve/piston and or damage it. Only run it slowly for short periods, then shut down the engine. Move the piston away from TDC, and allow it to cool down. Fire it up again and repeat, gradually building up your speed.

Oh, I almost fried my TM because I didn't check this. MAKE SURE YOUR COOLING HEAD SCREWS ARE DOWN TIGHT!!! I did not check this and while breaking in my TM, my temps shot to over 400f due to the leaning of the mixture, not to mention it leaked and burnt fuel all over. Luckily, I shut it down before it caused any major damage.

Toxik

Ok, Ill try to richen it up more and check the bolts. What are your needle settings?

NITRO FUMES RULE

You could have an air leak some where causing a lean condition that can't be tuned out
by richer needle settings. I would take some silicone sealer such as Permatex Ultra Blue
and seal the engine backplate, carb base and you can use teflon sealing tape on the main
needle threads. Be sure to use only a small amount of silicone sealer on the backplate
and carb base, just enough to get the job done as you don't want any to get into the engine.
I would also replace your fuel and pipe pressure lines because you can have pin holes in the line
that you can't see and this can cause problems with your tune and overheating. Lastly check your
fuel tank O ring seal in the cap. Mine was cracked when I went to break in the OS TZ 18 in my Revo.
This caused a problem with high temps till I changed the O ring and I have not had a problem since.
I always seal all my engines with silicone sealer when new and change fuel lines at least once a year
possibly more depending on how much you run. This is a cheap fix and will possibly eliminate your
problem. BTW make sure you only use oxygen safe silicone sealers availble at any auto parts store
because some silicone sealers give off corrosive gasses when they cure and can harm your engine's
internal parts.

If you are not smelling nitro fumes and listening to the sweet song your not LIVING!!

Toxik

I'll check for airleaks today or tomorrow. I didn't even think about the o-ring in the fuel tank. After sitting all winter I guess it could have dried out.

How about the needle setting on the carb guys. Someones got to know that.

REVO-Beat-U

OS .18 TM engine settings are as follows:

Needle Settings:
- High Speed Needle (Needle Valve) 2-1/2 turns out from closed
- Mid Range Needle (Mixture Control Valve) Screw head is exactly
1/2 turn in from flush with the carb body (pg 22 of manual)
- Low Speed Needle (Metering Needle) Screw head flush with
ball link body (pg 22 of manual)

You are running the exact same engine/pipe combo I currently run. I just broke mine in over the last couple weeks. I am running O'Donnells Racing fuel in mine with LC3 plugs. I did however use the heat cycle break in method instead of the one you are using. My engine temps were around 200 - 220. If you didnt change the engine settings that the engine came out of the box with, I would say you have a problem someplace causing your temps to get up that high. I would check everything out to find out what is going on. Check for air leaks, reset the factory settings on the engine, check bearings to make sure something isnt froze up. Do the tires, flywheel, tranny, and anything thing else that moves do so without a large amount of resistance? Just take a bit of time to go over the normal stuff to make sure everything seems to be alright before you hurt the engine.

Zikes

As IceWindius says make sure to check the head bolts mine were loose and my os .18 got up to 520. Stupid me I touched the motor before checking it with a temp. gauge and now I got what looks like a marble on the tip of my finger.. Once I removed the head the head, block, and top of the piston were completly brown I cleaned it up with some denatured alchohol check the head and block to make sure the was no warping put everthing back together again and it works perfectly now. oh and make sure not to loose the shim when you take the head off.

Freezetron

Damn, so Im not the only one. I tried to clean off the burnt fuel but I gave up, didn't have dentured alchohol with me.