Possible Fuel Contamination
Thanks Mr. Turk. I've been running alcohol this year. But this is my first year. I put the APD carb on it and I haven't touched it , not even the idle speed screws. I'll try that. It's really hard to get any temp in it.
That’s a sign it’s fat everywhere. One thing I learned the hard way (as in BTDT) is keeping track of what heat range of plug you are running.
If you are fat like that you can keep screwing in hotter plugs and it will love it. Love it to death.
And that death is called “back siding” the piston. The plug is so hot that the one side of the piston sticks in the bore.
I had seen it before but not on my junk. And I heard lots of myths about why it happened.
The truth is too hot a plug does it. And it will do it in one run.
After that I picked a plug heat range that fit my compression ratio and left it alone.
If it looked cold I took fuel out of it until it had heat in it.
Also, I learned (the hard way) that you can do the same with timing.
When they are fat you can keep jacking timing at it and it will love it. Right to death.
So whatever timing it needed for gas is where I set it and I had a plus 2 degree limit. If it needed more than 2 more degrees of timing I take fuel out of it.
That’s just a couple of reasons why I went back to gasoline. I upgraded the cooling system and made more power and went quicker and faster.