JIMARRINGTON

Just had a local repair shop give me a Troy Bilt weedeater. I have not had a chance to look at it closely but seems to be a pretty good size motor. Does anyone know what kind of engine comes on this.

He also gave me a dissasembled Featherlite that is probably an 18cc Poulan. Told him from now on to drop all his old ones with me.

Thanks
Jim

JIMARRINGTON

After I got home with it I had a chance to look a little closer. It has a rear mounted carb and muffler. The power head looks a lot like a Ryobi 31cc. Could that be what this engine is?

Jim

JIMARRINGTON

I am convinced now that it is a Ryobi 31cc. Just what I have been looking for. I have started to dissasemble it. It has a Zama carb. Right now though I am stuck. I cant figure out how to remove the clutch on the end of the shaft. The clutch has to be removed before the front housing will come off. Does anyone know how to remove it?


Jim

tim220225

My Feedback: (4)

I have used an impact wrench. The threads should be left hand.

JIMARRINGTON

Thanks but there arn't any threads. What I am calling a clutch is a big round device in front of the front housing. It has about a 1-2 inch snout on it that has a sqare hole for the trimmer cable to key into. It freewheels on the engine until the engine is turning. I would think that it would have a snap ring or something on it behind the bell but I cant see in there to tell. It also has some front to back play as well.


Jim

JIMARRINGTON

here are some pics

JIm

JIMARRINGTON

here are some pics of it

tim220225

My Feedback: (4)

Can you see a screw down inside the metal shaft? You may need to use a screwdriver to hold the flywheel from moving while unscrewing the shaft.

camcclellan

I bet tim is right. If not than The shaft should screw off.

aero nut

I usually cut the square part from the clutch holder wit a cutting disk then you'll see the screw that is holding the housing, the screw is a torx type screw that is why you can't take it of wit a regular philips or flat screw driver, cut it right wher it starts to widenn.

JIMARRINGTON

I stuck a long flat screwdriver down the hole in the clutch and could feel a screw in there. When I turned it, it turned the motor. So I guess I need to lock the flywheel to turn. Will try tonight.

Jim

P40 Maniac

My Feedback: (15)

Take out the spark plug and put some rope in the cylinder. This will hold it for you.

JIMARRINGTON

Ok. got the clutch off and the flywheel. This appears to be the long shaft version of the Ryobi.

Couple of questions.

I have been looking at the conversion parts at wacker engines. How does the prop hub attach to the crank and what do I need to do to the crank before installing it?

The Zama carb throat looks really small. What would be a good Walbro carb for this engine and where would I get one cheap?

This engine has a remote primer bulb. Could this be mounted on the exterior of an airplane and used to prime the engine if the engine is fully cowled?

Are there any advantages to changing the stock muffler to a wacker muffler?

With the parts available from wacker engines, this looks like a pretty easy conversion.

That is if the engine runs. It was a freebie and I have not had it running.


Jim

tim220225

My Feedback: (4)

Try this link and look for the Ryobi kit:


http://carrprecision.com/Pages/prod02.htm

Should you use electronic ignition you may need a different prop hub. Also try this link:

www.ch-ignitions.com

JIMARRINGTON

What size prop will work best on this engine? Looking to put in the Dynaflite SE5a. From what I have seen so far on the forum most people are using a 18x8 or 18x10. What about a 16 to 17 inch prop?

I think I see now how the prop hub works on the long shaft. The hub is basically a spacer. then the prop goes on and a nut holds the whole thing on using the threads already on the shaft. Tell me if I have this right.


Thanks
Jim

rangerfredbob

My Feedback: (13)

yep, that's basically the idea with the long shafts, if you want it a bit more secure, you could drill a hole for a roll pin in the flywheel and a corresponding hole in the hub to make it a bit more secure

most people going with stock ignition and everything go for 18 6 as far as props go from what I've seen...

JIMARRINGTON

Thanks for the info on the prop. Hope I have enough ground clearance for the 18" prop.

The throat of the Zama carb looks really small. Do you guys recommend replacing it for another carb? If so what size and brand.
And where can I buy one.

Jim

rangerfredbob

My Feedback: (13)

if I remember right, the optimal is a 11mm venturi. I don't know part numbers for walbro's, but what I've done is get random lots of carbs off of ebay for like $15 for about 8 carbs, there's website's out there that list the venturi size for any certain walbro part number (I had a good one, but don't have internet on my home computer at the moment). walbro carbs list a number in 64ths of an inch on the intake side, what you're looking for is a "28".

I think I have homes for all of my carbs in that size range at this point otherwise I'd offer one up... I do have a few smaller ones around all the way down to 11/64" venturi, but that's not helpful to you

JIMARRINGTON

Just got the jug off my engine and alas the piston and jug are scored pretty bad. Looks like it will need a new piston and jug before it will run again. Do yall know if it is worth the trouble to try and replace them considering I have absolutely no money in it at this time? If so, where would I get parts for it. Or maybe a head that has already been ported? Otherwise its back to the drawing board on this one.


Thanks
Jim

tim220225

My Feedback: (4)

Start scrounging the repair shops. Actually Harbor Freight and even Lowes, etc usually have these as trimmers for under $60.00 many times and I have seen them at Lowes for about $100.00.

mikenlapaz

fIND ANOTHER ENGINE AND START A JUNK /SPARE PILE.

av8tor1977

My Feedback: (6)

If you can find an older Ryobi engine, they are easier to convert. The engine crankcase assembly needs no cutting/grinding to be used in an airplane.

AV8TOR

JIMARRINGTON

Back in business again. On my way home from work today, I stopped off at our local West Street Auto, used to be Western Auto, and asked if they had any old trimmers. They said how many do I want. So I came home with 3 more Ryobis and two Featherlite 25cc engines. So time to start taking apart and see if I can make one or two usable engines.

Jim

JIMARRINGTON

Got the first one tore down. This one must be an older model. The metal piece that circles the flywheel bolts on. My excitement grew when I saw that. That means no grinding and filing. When it came off, it immediately looked like an airplane engine.

However, When I got the jug off, I found that the piston only has one ring. It also has some scoring on the piston skirt. Not around the ring or at the top of the piston. The jug had a little scoring but not a lot. There was a lot of carbon build up on top of the piston and the piston ring was stuck with built up carbon. I pulled the ring out and will try to clean it if you guys think that it will still be usable. Does the scoreing or scratching render this jug and piston unusable? If so, if I can find another good one in one of the other engines, can I use this crankcase. It is too perfect.

Should I start another thread or just rename this one now to "The search for a good Ryobi"

Jim

JIMARRINGTON

If you can find an older Ryobi engine, they are easier to convert. The engine crankcase assembly needs no cutting/grinding to be used in an airplane.
I just saw AV8TOR's post. I sure hope I can make this one work. I sure wasn't looking forward to all the grinding.

Jim