hello I have received a plane LESS an engine it HAD a US 41 but I wish to convert an weed wacker engine to power it what size weed wacker engine is powerfull enough to compare to a US 41 - THANKS!!!

Puddler

I do not think you will find a weedwacker engine that has any ware near the power the US41 had in it. Most weedwacker engines are 32cc or smaller. With Homelite and Ryobi being the most popular. These engines put out a lot of thrust for their size, but do not put out the power as compared to a US41. If you want something that comes close to the US41 you will need to use a chainsaw engine like the homilte 33cc or 45cc. The 45 will have almost the same power as the US41, but will be heavier. You can put on a CH ignition and the weight of the engine will than be about the same. This does cost more and after you buy the CH ignition and the conversion parts you might as well have just bought another US41.

What type and size of plane is it you have. Maybe one of the weekwacker engines will do. I believe the Ryobi 31cc is the easiest to convert, but the homelite 25cc has better power. I fly a Ryobi 31cc on a Balsa USA stingray 120 thay weigh's in just under 14 lbs and she flies great. The plane has an 83" wing span with 1276 sq. in wing aera. If your plane seems to be this size or close to it either the Ryobi or homelite should fly it just fine.

Good luck

Thanks for the info -the plane is a P -51 89" wing span not sure on the weight - I will opt for the US 41

I must disagree, I just converted a homelite 45 using wacker engine parts and the whole thing cost me about $175 bucks. Now if you want to throw away $225 go ahead. But with very little work you will have a great engine. As far as weight goes the us 41 is just a chainsaw engine anyways, you would need to get an rcs engine to save the weight. Also since you are doing a War Bird you will need to add the weight back in for balance so who cares.

Check out Wacker engines for parts and Harborfreight.com for the Homelite saw. They put it on sale for $109 buck, you just have to keep your eye open.

I am putting my engine in a 1/7 scale p47. When I ran the engine on a test stand bolted to my picnic table it almost pulled it over.

If you need help on your conversion myself and other would be happy to assist.

I think he was talking about a weedwacker engine. Of course there are plenty of chainsaw engines that are more powerful. Poulan 46cc is another popular conversion.

Correct -I have an old homelite weed wacker I think 22cc runs fine but it is not powerfull enough
As far as I can tell my options are to 1 buy a US 41 or 2 find a simular chain saw engine
THANKS for the help