Are there any known motorcycle/moped/minibike engines worth converting? It all comes down to price and weight in the end, but I wondered if there are some motors that are right for big slow scale flying planes . I personally have my 1/3 pup, and it will be begging for some extra weight up front. It seems someone might have seen them done... I know I have heard of BIG saw and Husqvarna cycle engines being used on enormous planes...

I wouldn't even mind a four cycle motor that has to be mounted up right and flown that way most of the time.. Just bored and curious, thought I'd ask..

By the way working on my first gas weedie crackerbox boat, its coming along, and I found a small weedeater in someones curbside garbage today while making a parts run... GUESS what was wrong with it? ha ha ha ha the plastic trigger was broken !! poured in gas, primed..BBBBRRRAAAAAHHHHHHHHH purred like a kitten....

I got my 30cc Homelite line trimmer engine the same way. I haven't tried to start it yet and won't until I diassemble it, check stuff out and then I'm going to convert it to a boat outboard motor. There are tons of good motorcycle engines out there. Problem #1 you can't use the carb if your plane will fly up, down, left, right or inverted. You'll have to investigate a diaphram type carb. In most cases you'll have to remove the transmission from the engine crankcase. Now, if you can locate an old Norton 750, Triumph 650, Harley 1200 the job is done for you. Why don't you just gravitate to ultra light aircraft? You'd save a ton of money on radio systems.
Bill

ULTRALIGHTS? you haven't seen me fly ! ha ha ha

I have seen Rc airplanes with ultralight engines however....

These two stroke engines are used on some scooters. They have two rings and are very strong running engines.
[link]http://www.duropower.com/index.asp?FID=3&level=1[/link]

Here's something to think about, I have a "LAWN BOY" two cycle engine under the bench that I have been saving in case the one I use for mowing the lawn dies. I have only had the one I use 12 years, and I was the second owner. So, I have looked at a conversion. I know it will need a pumper carb, but it has a double reed valve, two rings, and good compression. Haven"t figured the displacement yet, and temp has been below "0" the past couple nights. Will send more info when I get it. Flathead 4

Flathead,
I have a Lawnboy engine too. I believe you are looking at somewhere around 140-145CCs (cant remember exactly). Ive cut one down and chopped off the shaft for the mower blade. Havent done any more than that, I was worried it would vibrate a plane apart but would still love to try it. If you ever run it start a thread, Ive seen others talk about it in the past but have never seen anyone post any numbers.........mark

This was on the link posted above http://www.duropower.com/item.asp?PID=439&FID=3&level=1

I wonder what the trimmed down weight would be? It says it starts around 28 ponds, then of course a new carb would need to be found....this thing might be fun on a big floater if you could get it all squared away...

I know this is not a motor cycle engine-as being politically correct for you "this does not pertain to the post" people-But it is a 63cc engine for $140-plus you have a generator!!!
http://cgi.ebay.com/NEW-1200-1250-Wa...1%7C240%3A1309

OOPS!! this same duropower website has a 1000 watt one for $130 shipped-same 63cc and 2 hp engine-

even better a 4 stroke 2.5 hp one 80cc for $20 more!!!
http://www.duropower.com/item.asp?PID=40&FID=2&level=1