i pulled the motor out tonight took off the mounts, took off the exhaust and carb, glowplug, i put some fuel in any entry point and flushed it out throughly with clean fresh fuel.... When it dried i used some after run oil in it i made sure the carb was clean and properly set.... Packed it up in original packing and wrote the letter and sent it off.... I couldnt find the instruction manual, and i didnt put the glowplug back in it, i hope i dont hear about it.... Heres the letter I have so far i will send it out monday, let me know if i should change anything in the letter....



Letter reads:

O.S. MAX .15 CV-X


To O.S. ENGINES MFG. CO
Brand new motor only 4 days old. Since first startup, when engine temp reaches approximately 220-240 Degrees (EXERGEN TEMP GUN), motor loses compression (Little Resistance On Pull Starter) and fails to idle and to restart. When motor cools to room tempreture full compression is restored and starts on the first pull. Followed break-in instructions per your manual. I have used OS motors before and never had a problem. And was disappointed with this straight from the box. This motor was in my touring car, and hardly saw road time. Paid almost 150 dollars and wasn’t expecting disappointment. Local Hobby Shop confirmed that something was not right. Also tried a new OS Glow plug with new gasket, with same results.
I was assuming it could be overheating, but followed break in procedure settings, temp gun read 220-240 degrees, and water hardly boils off the head. (6-8 Seconds For Water To Evaporate)

Used With Motor;
OS glow plug that came with my motor.
Stock exhaust.
“Clean Flow” New In-Line Fuel Filter
New Bottle Trinity Break-in Blend 20% Nitro
Hobbico After-Run Oil
And the 2-element air cleaner that came with the motor.

I had contacted OS Tech Support, and was told to check back plate and head bolts for tightness. I was also told that it could be a case flaw, or leaking bearing etc. I chose your motor over HPI due to good history. Due to the warranty I did not want to tear this motor down to take a look, I will leave that too you.




Appreciate Your Time
Anthony Rubano