I would say that your motor is too hot (lean). Perhaps when it was broken in, it was broken in wrong, or ran too lean-Not enough fuel. No engine will last if it was broken in or ran too lean.
My gas engines-I've had (5) .15s in (5) different gas trucks and my engines never ran over 190 degrees unless the piston and sleeve was worn or wearing out.
If you wanted to stick with the mach then try replacing the piston,connecting rod & sleeve. If the piston, sleeve and connecting rod is going to be more than 60 dollars you may wish to consider buying another engine .15 for your truck.
Another recommendation in addition to the motor rebuild would be to purchase a cooling head designed for your engine depending on the engine you use.
Odonell, crazy nut, are companies that make them. These devices can help your engine run cooler (by as much as 20 degrees cooler or more) and your engine will last longer
I cant comment on the other .15 engines but I can comment on OS motors-They are reliable, you can buy parts for them almost anywhere (except for some hobby people stores) and the replacement parts wont cost you an arm and a leg. A piston and sleeve would cost around 35-43 bucks. Connecting rod should be around 10-14 dollars. Ebay (RcBoyz) is a good cheaper source for parts!
When you go to rebuild your engine (if you decide to) just take your time, read the instructions for your motor and follow it to the letter-and be patient. If you do it right your motor should run a few gallons (3-4) of nitro with no problems.
Dont forget..It doesn't hurt you to run your truck more on the rich side instead of the lean side!
regards
Last edited by threeEwes; 07-03-2004 at 10:10 PM.