BOOST

The motor is supposed to be tight, especiaaly since you haven't had it long and have only run a few tanks. The piston shouldn't reach the top of the sleeve, there needs to be room for detination. and DON'T SAND ANYTHING, very bad idea!!!!!. Just clean everything and put it back together. Then try it again and see how it goes. Don't leave fuel in the tank or the line for extended periods.
What plug are you using???

z28mccrory

iTrader: (12)

I wasn't actually planning on sanding anything, was just using the concept as a way to convey the point of how tight the stuff was

I will try to find some lower content nitro fuel, and use a lot of after-run oil and see how things work.

If i end up not having any luck with this, and want to buy a nice motor to start racing it with, what do you guys suggest. I know if i buy it from the tuners that i can purchase it ready to go, and i wont have to go through the break in process... as i seem to not be very good at it Reliability is more important that having the most powerfull motor around. I only planned on racing electric, and while i would like to race my nitro truck from time to time, i would rather just have a middle of the road motor that is easy to start and tune.

ezveedub

iTrader: (17)

Maybe an O.S. 12 or even a Jammin .12 with slide carb! I think is would enough power!

sport10

I would recommend a OS motor like the .12 cv-r. The only thing is you will find the same thing with the new motor as the one you have now. It will have a very tight fit at the top of the cylinder. Best to learn on this motor and save the better motor for later. Also, make sure you are getting the motor up to temp (200 degrees) for your runs. You may have to wrap aluminum foil around the head to decrease the cool effect some to achieve this.

z28mccrory

iTrader: (12)

So am i understanding this right... that the motor is fine... but it locked up because i didn't use after-run oil? And that its still fine i just need to use the oil?

ezveedub

iTrader: (17)

Just run a more oil content fuel. Race fuel with 12% is usually not enough oil for break-in and your motor may not see that much benefits to justify the low oil fuel. O'Donnells RTR is good, but like I said the Omega 10 or 15% will provide enough oil to break the engine in. The glowplug should be a hot type, since most small engines don't have enough mass to hold heat well to keep the glowplug lit good. Remember, lots of smoke and rich enough to limit you full speed. As it breaks in, it will be too rich. Just lean the needles enough to keep it running OK. It will get to a point where it will not need anymore leaning and keep the same performance. At that point, you can lean it a bit more to get so speed, but not too much where you run hot.

DirtRacer

yea like said just clean it and then heat the head up so it expands and then run it in for another 2 tanks and watch the temp with a temp gauge and have it just rich enough to lube the engine and it ll be alright, it will hang up when you leave it idleing due to the pinch from the sleeve, and make sure to mark the flywheel when the piston is BDC so it wont get stuck and you ll know that its BDC without taking the exhaust of, as you would know if your experienced enough.

GHETTOTEACHER

After run oil substitues are many. I use Slick 50, Miltec, 3&1 one oil, Mystery oil. Any oil that keeps moisture out of the motor.

I think that the grass overheated the motor. The motor is ok. I would take that carb apart. (just me)

A really good replacement motor that is dependable, strong and reliable is the O.S. 12. Check it out!

sport10

It has nothing to do with afterrun oil. The motor is new and still tight. It will return to this way every time it cools off till it is broken in. This is because the sleeve tapers down at the top. It is actually slightly smaller in diameter at the top than the piston by design. This way the piston laps itself to the correct size when the motor is breaking in. Make sure to put the motor at bottom dead center right after every run till it breaks in. You do not want the piston stuck at the top when the cylinder cools as it can damage the piston to sleeve fit. Use a flat head screwdriver to gently pry against the flywheel if the motor gets stuck in the pinch when trying to start. Make sure to heat the head to 200 degrees with a heat gun before trying to start it. After you finish running the motor run it completely dry of fuel and add afterrun oil. I just keep trying to start the motor till it will not run and the oil helps to keep the bearings from rusting. It is a real pain to break in a new motor but something all of us have to go through.

micrors4guy

iTrader: (50)

when you run a motor too fat it will accually hurt the motor. you should be keeping the motor up to atleast 200*. also it looks like your motor may have sucke a plug element into the motor and just beat that arround in the chamber.

z28mccrory

iTrader: (12)

Thanks for all the great info guys.

It looks like a heat gun and a temp gun are the first things on my list that i need to buy.

So store the motor at BDC... heat it to 200 before i try to do anything...

So why could the motor reach TDC when i first got it with no problems? Just so much oil in it from the factory?

Also guys, i dont think i overheated it when ran it in the grass... the reason i say this is because other then the time starting it and a lap or so around the parking lot... it MAYBE got 2 min of time in the grass... and it wasnt really tall or to the point it sounded like it was bogging the motor. It was probably 35 degrees out that day and the head barely even felt warm when i killed it.

Thanks again for all the great info guys. If it wasn't for you all i probably would have already got mad, threw this one in the trash, and got a new one on the way only to find out it did the same thing

rabidsquirrel

iTrader: (2)

Go to the paint department at your local Wal-Mart or equivilent and buy a heat gun (I.e. the kind you use to remove wall paper). Use this on the motor before attempting to start it. Get the motor up to or near 200*F, then start it. You'll find that breaking in a motor suddenly becomes much easier if you do it this way! The motor will thank you by living longer and performing better as well!

BOOST

These motor if broken right and treated properly can and will last a long time with plenty of power to propell these trucks.
I know I have two of them, had them for almost two years. And they have good compression still and I haven't had to rebuild one yet. Had more than a few gallons in them so far. I always store them at BDC before they cool with after run. Always check temps while running, I use good plugs (os#8 was my pick). I only used 16% nitro, you can use 20% obviously but I found 16% was plenty. Make sure it is up to temp before trying to tune it also.

cota348

I guess you got the main idea on what to do.

What everyone else kept on saying but I don't think made enough strong point was that you should not try to fire a new or old engine close to freezing point. It is better to warm it up before hand.

DOMIT

iTrader: (1)

The residue you are referring to is probably just a buildup of oil and sludge, from running rich. I wouldn't worrry about it.

Put a new glow plug in, heat the motor up with a heat gun, and see if it will start up. I don't think there is anything wrong with that motor whatsoever.