If you have the ability, you might be a lot better off to return the engine for a refund. I'm not going to go into engine details about the GRPro, but there's still some room to improve with this one.

This may be of help. A couple of months ago I tried out a RCGF 100 twin. It had a few issues but they listened and have incorporated quite a few improvements. They added bearings to the wrist pins and made some other modifications to make the engine more user friendly. It started out with some very nice basics. It has an excellent crank, very nicely machined case that's well matched to the cylinders, uses a Huskvarna clone carb made by a company named "Emas" in China that exactly clones all the chainsaws, and generally is pretty well made.

The one I have was sent out for minor modifications to improve the performance. Information regarding those improvements was provided to RCGF for them to incorporate into their production process. Engines having those improvements should be just about on the market now, or very soon to be. Overall it should be a very nice bargain priced 100cc twin, weighing 5 lbs, 3 ozs, making it the lightest 100 available that I'm aware of. Pricing may be comparable to the GRPro that you now have, but I'm not certain of that.

My engine is currently turning a 3W, 26-10 prop at 6,400 rpm and it has a ways to go before break in will be complete. Some other modifications will be tried to see if even more can be done with the engine, but those are limited to simple carbueration mods that anyone could do.

Contact Andreas at: [email protected], ++-261-81-129-4050, for particulars and availability. You'll have to copy and paste that info to a folder since it was not "linked".

This should turn out to be quite an engine and well worth researching further.