I have used the Carr parts on three engines. One of them being a Ryobi. Everything was made well and they were always very helpful when you called them on the phone. I know that Carr is a good place.

B & B also has a good reputation but I personnally don't have any experience with them.

The Ryobi does tend to be longer than typical glow engines.

By theory, it is possible to make a shorter engine from the long shaft engine than from the short shaft. After you look at them and the parts, you will know what I mean.

To buy the bigger carb from Carr will make a nicer engine for model airplanes.

Run the engine as a leaf blower some before you convert it. A couple tanks maybe.

It is very unlikely that you will be able to start it by hand. A regular electric starter works OK on mine.

The motor will get a lot nicer after 2-4 hours running. But try to do most of it in the air.

After you get going with it, you will find that it will not be or sound that much different from a glow engine.

You will find that gasolene stinks inside your car compared with glow fuel. You might want to try something like Coleman fuel or something like it down there if you are going to haul it inside the car.

The engine should run right around + or - 7,000 rpm. With the stock weed whacker carb you will want to use a 16-10. With the big carb you will want to use an 18-8. Remember that the engine is a torquer not an rpm engine. So if you start running it at 9,000 or so, you will find that you will have overall less power.

The engine has a stamped steel connecting rod in it and some of the counterbalancing is in the flywheel.

Use like a 12 oz tank. It will run forever on a 16 oz.

Good luck

Jim