I have an older .25 cc Homelite weed whacker engine I am interested in converting to RC. I have always used nitro engines, and I am new to converting whacker engines to rc, if it is practical.
My engine has a (screw on) shaft that holds the flywheel in place, and there is a square (hole) in the end of the shaft to insert the shaft cable. Does anyone know if the screw on shaft already on the engine can be threaded for a nut to hold a prop, would this work as a prop adaptor? I dont know exactly how weed whacker prop adaptors are supposed to be mounted, as I am new to fuel whacker engine conversion. I have searched to shaft conversion kits, but unable to find any and I dont know exactly where to look. I have also read that the flywheel key is aluminum and will shear extremely easy. I know I would have to cut off the fins and all unnecessary metal to bring down weight. Would the stock carb work that is on it, or is there a special one I need to get for good performance. The plane I am working on is a Sig Four Star 1.20. I flew one once before with an Evolution 1.00 engine and it had plenty of power for sport flying.
Would the conversion be worth the effort, or would you advise not to try it??????????

http://www.rcuniverse.com/forum/engine-conversions-92/

While we made a lot of the Homelite into
model engines years ago and they ran very well.but I think now you would be way better off to find a good used DLE 20 or 30 and probably less cost also.Or new Valley View 20.If you have never done a engine conversion there is more to it then looks. 20 CC does very well in the four star 1.20.A friend flies one with Evolution 15.This engine is way more money and just as heavy as DLE or VV 20.
Good Luck BCCHI

I had pretty much decided against Homelite conversion. I like the fuel economy of gas, but was thinking of trying to save some money on the engine; which is why I was looking at the Homelite. The Four Star 1.20 is going to be a winter time kit build, and I still have time to be looking at engines. I will be looking for a DLe 20 or 30 used in the meantime. I had an Evolution 100 in an older Four Star I had a few years ago and it flew the plane great, but I dont see the 100's anywhere now. Did they stop production on them? Also, I am curious about the Evo 15, I have not heard of it, and is it a gasser or glo fuel?

The Evo 15 gas engine is not as desirable as a DLE 20 or VV 20

I would put at least a 20cc in the Sig 120.

I have the Sig 4 Star 60 with a 15cc gas engine and it is about perfect. 15cc in the Sig 120 would not be enough power in my opinion.

Probably would go bigger than 20cc if it fits and the weight is not too much compared to the 20cc.

There's a Four Star 120 at the flying field with a DLE 20 and it flies as perfect as any RC plane.

I have a VVRC 20 cc on my Ultra Stick, several friends have DLE 20's and really we can't tell any great differences, mine has been flawless except for a RCXL ignition problem, replaced by Valley View on warranty. Great service...
Love the engine and would buy another. I have a DLE 35 RA and it also a great engine so not set in my ways, both are good......