28cc Mcculloch

I have had this motor for years. I actually started converting it for a boat 10 years ago or so. I didn't know any thing about it then and i just found out what it was today.

Any suggestions on this motor, good or bad. I have the stock carb off of it on a different motor right now. Any suggestions on a carb maybe?

I am not looking for a race motor, just some thing fun that i can replace the wimpy little 21cc echo in my prowler.

Thanks, Dan

It's probably not that much different than a Homelite,so a Walbro WA 167 with an 11.11mm venturi or any carb with around an 11mm Venturi would work.You can run it air cooled if you're not using a hatch cover or get it water cooled.You can gut the cannister muffler and put two 1/2" stacks out the top of it.Getting the engine modded by someone would give you a little more speed,but it wouldn't be a race engine by any means.Just a fun sport engine.If you want to do the mod route and can't do it yourself contact chipbreakr on Jim's Boat Dock or RC Universe.He has modded McCullochs before.A place for parts to watercool it,manifolds,tuned pipes or mounts is www.majorsmackdown.com You can check the venturi size of any carbs you find at www.walbro.com

Spent the other day working on my 28cc. I machined a billet aluminum water jacket. Turned the fins off the flywheel. Made a new coil mount. Im not real happy with the mounts. Need to make some sort of exhaust adapter. Ridgerunner sugested a wa 167 carb, what about a wt 257. Im going to get it running first then do some port work.
Thanks


My phone will not let me post a picture. Bad phone go to your room

Gave my phone a good beating.

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I have a modded 30cc Homelite with a carb that has the same venturi as the WT 257 and it runs great.I don't know if it would on a stock engie ,but you could try it.
Does your Mac have the kind of muffler that attaches with springs ? If it does you could buy or make a manifold simular to the one on Major Smackdown's site that's shown as a Mac CNC Exhaust under McCulloch items.I had an old McCulloch 28cc trimmer that had the kind with the springs,but a newer 32cc has a bolt on muffler.You could make you manifold water cooled like the one on the Homelite engine above.There's supposed to be water fittings and water line on the right side of the manifold,but I didn't have any in it when the pic was taken.

It has the spring mounted muffler. There is some space on both sides of the port where the casting is real thick. I may drill and tap holes there. The bolt spacing would be 1.5 inches. I might buy a water cooled flange for a zenoah and see if i can mod it to work.

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