av8tor1977

My Feedback: (6)

Hi,

Does anyone know what type and size engine this is, and if they are any good for our conversions??

Thanks,

AV8TOR

flipflop

It looks like an old 30cc Poulan out of a XR30 or XR 90 weedeater.
I've got one out of a XR30, it would make a good candidate for conversion except for one problem, it runs the wrong way! You can buy reverse rotation props and I've found the left hand thread taps for making the prop hub, might be around to converting it one of these days.

av8tor1977

My Feedback: (6)

Hey, thanks for the info.

Not a problem on reverse rotation, as I will not be using the mag, but will instead go with electronic ignition. The only problem will be if the prop will stay on I guess! What do you think?

AV8TOR

Kraut

My Feedback: (1)

From the looks of the cooling fins - it appears to me that it runs in the right direction (clockwise from the rear). The fins on that engine are curved very similar to the fins on my Ryobi - and I know it runs in the "correct" direction. Am I missing something obvious?

bdtsr

My Feedback: (5)

Doesn't matter which way it runs originally. If you add electronic ignition to it, you can make it run any way you want. My Tecumseh engines all run clockwise when viewed from the prop side (front of plane). Two strokes by design will run both directions, just a matter of ignition timing. Yamaha does this with their 2 stroke golf cart engines. This eliminates a transmission.

Volture

My Feedback: (1)

It's indeed from an old weedeater brand trimmer with the all enclosing aluminum case. My mag has the notation "reverse rotation" on it. Keeping the prop on should not be a problem. look closely -- if your's is like mine, it has right-hand threads on the shaft! The flywheel has the same Phelon P/N as one of my other normally-rotating Ryobi engines. As Kraut pointed out the fins are curved/angled the same way as for normal rotation, and given the P/N is the same, I'm pretty sure if you put a Phelon coil from a Ryobi on it (yes it fits fine) it'll turn CCW. The back shaft side casting is also a pretty good attachment point.

I haven't checked the lateral balance of mine, but it might mount nicely with the jug sticking out one side and the carb out the other. Now for that muffler mod....

R. C. Day

My Feedback: (7)

Av8tor1977

I have two of the motors that you have shown. It is a 22.3 cc Craftsman string trimmer motor. I have started the conversion on them, but have not put them on a diet yet.

av8tor1977

My Feedback: (6)

Thanks for all the info guys. I just love all engines and converting them for R/C is a lot of fun. I knew I could run it either way with electronic ignition. That is the only determining factor in which way a two stroke runs; the ignition timing. I once worked at an airport as a manager for a maintenance facility. We had one of those two stroke, run both ways, golf carts to run around the ramp. I always thought of rigging something up so that I could advance the timing by hand once it started in forward "gear", to get more power out of it, but I never got around to it. (They are timed at around zero so they will start and run both ways.)

Anyone have any idea what kind of prop/rpm this little engine in my post might turn? Did we decide it's a Poulan?

Thanks again,
AV8TOR

Volture

My Feedback: (1)

Unless a two-stroke has a rotary valve, that is.....

bdtsr

My Feedback: (5)

True....forgot about that type! So used to dealing with piston port and reed valve engines.

flipflop

One more little problem, mine has excellent compression when turned clockwise, hardly any at all when turned counterclockwise. I don't know if it's wear pattern, ring end gap position or what that causes this.