I have been using an new O.S. 15CV-X for about four months, but it has already lost its compression, and won't run after a few minutes when hot now.

I am new to nitros, but I didn't run the motor too lean, it never seemed to get very hot (other cars in the same races were hotter after racing), and glow plugs looked great after running. I have had problems with fuel delivery at times due to leaks in various places, which has made it run lean for a few short periods.

O.S. specifies to run with at least 18% lubricant, but the local hobby shop told me that their 16% lubricant mix was all right, and I have been using that. Could that be the problem?

Can anyone shed some light on this?

I'm getting another O.S. 15CV-X as the speed of my car was awesome, and no-one in my club could beat it in the straight.

Kindest regards,
Chickentrader

Engines can wear out really fast even if they are run lean only for short periods of time. 4 months is not so bad after all...

Thanks R1RCR, my own lack of experience has probably contributed to the problem, not realising the problems with the leaks, and preparing the car properly.

Running too rich is just as bad if not worse than running too rich as it increases wear do to a piston/sleeve not being up to temp and allowing excessive wear. The next big killer is not cleaning the air filter properly or often enough.

How many gallons did you run in 4 months? 6 gallons in 4 months is a lot but would be considered a pretty good life span for an engine run by a noob.

First engine I suppose!! Ya if your getting the knowledge in on your first one.. I have a sneaky feeling that mines going to go soon to!!! Thats ok though cause you learn how to tune with your first and how they run!!!

Its not a great loss those types of motor are under $100 normally. What you can do is get the sleeve pinched if your wallet isnt doing so well. Im sure you can even find someone who can do it at your races probably. Ask around.

Also 16% is considered high oil content. 18% is rediculously high. Most racers use 12% and under with no problems. Even more so some of the top racers can run a range of percentages , even as low as 9% and lower.

I run 10% oil a good mixture of power and oil. The less oil the easier the engine clears out and goes. With more oil it keeps a load on the motor and sometimes you might not tune it right. Stick with more of a race blend if your racing.