Originally Posted by
Cougar429
I might be on the wrong track, but what fuel are you running? If over 5% you may be detonating and destroying the plugs. That would also account for the overheating.
I've had to open up the combustion chamber, a trick described in the notes now at Fayeteville:
http://www.fayettevillercclub.com/id59.html
If not had a boo at these they cover some good points on the 40.
From the start I have used fuel with 5% nitro and 20% castor. I have a filter on the fuel line. I did notice however that dirt had gotten between the prop driver and the crankcase. I am wondering if it got inside the front bearing, which is unsealed. But the bearings feel smooth. However, when I was starting the engine, I could hear a scratchy/high pitch sound like metal on metal scraping. I have not opened up the engine except to look and the cylinder liner, which doesn't have any scrapes or scratches. I thing I will completely disassemble the engine tomorrow to look at the lower end. This engine had been running quite well with the fuel and giving good performance when it suddenly began quitting.
Destroyed in Detroit
