Craftsman 25cc Conversion
 

Hello:
I'm doing my first weedwacker conversion and I've read through many posts.
The attached pictures show the motor I got from an old Craftsman (probably 20 years old)
25cc weedwacker.

Could anyone tell me the actual manufacturer of this motor? (Poulan, MTD, Ryobi, etc.).
Is this motor suitable for an airplane? I'd like to keep the flywheel as-is, fins and all.

My other question is regarding the carb. It is a Walbro WA-226. Will this carb work or should I
buy a different carb? I see it only has one needle adjustment, not sure if it's the high or low end
adjustment.

I want to order the mounting plate, velocity stack and prob hub from wackerengines.com.
Not sure if the muffler can be changed out.

Thanks for any advice or info on this motor and carb!!

RE: Craftsman 25cc Conversion
 

looks like a weed eater. check the rotation to make sure it runs the right way. the ones I've run across ran clockwise.:eek:

RE: Craftsman 25cc Conversion
 

Good point! Sorry for my ignorance here, but how do I check the rotation direction? Is this a physical rotation issue or a timing issue?

RE: Craftsman 25cc Conversion
 

Does it still have the recoil starter? That will tell you which way the crank rotates.

RE: Craftsman 25cc Conversion
 

Ah, unfortunately I already threw it out! I should have checked this prior to dismantling. Live and learn I guess...bleh!

RE: Craftsman 25cc Conversion
 

If you look at the fins on the flywheel, it looks like it rotates counterclockwise.

RE: Craftsman 25cc Conversion
 

Yes...I was wondering if the fins are shaped to "scoop" the air in the direction of travel, which would seem to make sense. In that case the motor would seem to rotate counterclockwise. I attached a better picture of the fins. Just not sure....

RE: Craftsman 25cc Conversion
 

I can't swear to it, but I think these are made by Poulan for Sears, and are quite similar to the "Weedeater" brand.

Sorry, don't really know much about the engine. The carb has to go. Needs an 11.1mm venturi DUAL mixture needle adjustment carb. Also needs the muffler gutted and supplied with much larger outlet area.

Magneto/flywheel rotation appears to be counter clockwise when looking at it from that side, which is good. Make sure the magneto nut is standard right hand thread; that will tell you for sure and is important.

AV8TOR

RE: Craftsman 25cc Conversion
 

Thanks for the input!

I just bought a Walbro WT-263 carb for $16.00 off ebay. It has high and low needle adjustment and 11.1 mm venturi that you mention. Seems like the right carb.

Wackerengines.com stated that they don't make a muffler for this specific engine. I'll have to find another muffler source.
Any ideas welcome!

Attached a picture of the exhaust port.

RE: Craftsman 25cc Conversion
 

It's a Poulan, basically the same as all the 18/21/24cc variants just a little bigger. I don't think I have any spare old style two piece mufflers left that aren't slated to engines or I'd offer one of my mufflers. Skip the backplate mount it just adds extra weight, instead get some long 10-24 screws that are threaded all the way or some 10-24 allthread and thread it into the back plate holes, thread on some nuts to hold the back plate on, will probably take two or three to take up the space needed for the curved back plate then put fender washers on both sides of the firewall of the plane and nyloc nuts on the inside of the plane, works great, I used this method on a 40 size stick so you can't say it's impossible... For the prop hub it should be 5/16-24 threads, only the long shaft engines are odd and I think they're just 3/8-24

http://i960.photobucket.com/albums/a...ril2010106.jpg
There's a pic of some 21cc engines I put together, take note of how far I trimmed the coil mount, that is far as I would go, no further, you can see the mufflers I use as bases, that style is MUCH easier to deal with. You'll also notice I used the stud method for the carburetors too.

RE: Craftsman 25cc Conversion
 

Wow, those are nice motors! Thanks for the input.

Did you fabricate the mufflers yourself? I'm having a problem finding a source for aftermarket mufflers similar
to the ones you have.

RE: Craftsman 25cc Conversion
 

yeah, that's the older style stock mufflers that aren't crimped together, baffles removed, stock outlet welded shut then a camp chair tube welded as shown from the inside. I'd offer to look through my stash and make you one but I don't think I have a spare or the springs to go with it, let alone the time to make one up... I've been home 4 days since last sunday (the 8th), I'm now in Saskatoon through saturday...

RE: Craftsman 25cc Conversion
 

Neat! I wish I had the same knack for fabrication. I guess I'll be stuck with the stock muffler until I can find a replacement.

RE: Craftsman 25cc Conversion
 

It appears very close to a Weedeater GT15T I just took apart today except for the flywheel design. And I'll have to cut the reed valve assembly out of the plastic enclosure. The Weedeater flywheel is so out of balance I was shocked. No wonder that thing gave me the shakes. As a matter of fact, doctors have given that a syndrome name but I can't recall it.
 This motor is already feeling much lighter than my Homelite conversion. Scrap the flywheel because of balance and magneto for weight and it may be close to two pounds. Give it a good spin and see if it wobbles in your hand.

Oh, and I'll need new crankshaft bearings. I hear 'em crunching. Maybe tomorrow I'll show a photo but I packed it up until I decide to go on or not. Compression is good but this motor has been frequently switched off by the Phantom Kill Switch Operator.

RE: Craftsman 25cc Conversion
 

Thanks for the input Chophop. Just waiting on some parts from wackerengines.com and I'll be ready to at least see if she fires up and will turn a prop. I bought a carb with a larger Venturi opening (11 mm) than the stock, so I'm not sure if I have to modify the plastic carb adapter throat to enlarge it's opening.

My engine seems very close to this one, although there are other slightly different model numbers.

[link]http://www.superxpower.com/pages/OemParts?aribrand=AYP#/Poulan_%2f%2f_Weed_Eater/TE450CXL_Gas_Trimmer_Type_1%2c_450CXL_Gas_Trimmer_ Type_1/Engine_Assembly_Type_1/03|~249|~912/032490003[/link]

I'll need new carb gaskets for sure me thinks.

RE: Craftsman 25cc Conversion
 

I've had one of the 18cc engines set up for gas/glow at one point before I found out there just wasn't enough compression to run (scored), but with prop, prop adapter and everything needed to run it was right at 2lb. The 18cc engines are a little lighter than the others though, the cylinder on the 18cc is a different casting than the rest of the sizes, I think there are only two different outer castings but I have never looked at the rest of the sizes that close, the crankcase on all of them is fairly similar (there are a few that are slightly different, mostly back plate seal wise)

The GTI 15T are reed intake rear exhaust, I've got a few of those too.

RE: Craftsman 25cc Conversion
 

Woohoo! Quick test run of my Poulan 25CC weedwacker motor after putting it aside for a year. Couldn't believe it worked. Now to find an old plane to
mount it on and give it a try (Yes, the velocity stack on the carb. is backwards !! Doh!)

[youtube]http://www.youtube.com/watch?v=Cp3tCs5mjlY[/youtube]