Hi all! I just came across two more weedwackers for conversion during this winter. One is a Stihl FS80AV and the other one is a Crapsman 32cc. I need to know the cc of the Sthil as Google says it's 25cc but the cylinder looks a bit small for that. The Crapsman I need to know the engine manufacturer because as usual Crapsman is absolutely no help on this one, maybe a Poulan?

The first picture of the naked engine is the Stihl

I would be grateful for any help

Thanks Rich

that craftsman is a McCulloch 32, I haven't seen any of them like that, they're usually the Poulan thats like the Ryobi being rear carb and exhaust

if you're interested I have a prop hub made up for the mac for using the flywheel, I swapped it over to gas/glow and just made a one piece hub for that purpose... I also have the trimmed mag mount plate if you're interested...

I believe that Stihl is a 25cc, there's been a couple of them on here lately, I have one, I never did get the Mikuni carb on that thing to work even after a rebuild... but I just put it together the way it came apart which could have been my problem...

Thank you!

That Crapsman has got to be the loudest most obnoxiuos weedwhacker I have ever seen!!!!! I had it running for a few mins and my ears were ringing for ages and my hands went numb!!!! As usual the previous owner messed with the mixture settings and wrecked it and that's why I ended up with it. A couple of mins on the mixture screws and it runs really well if not loud as hell! As for the Stihl, that was dropped on the floor or ran over by the previous owner and it broke off the front cover. I need to get it to my work and have the cover spot welded so I can see if it works ok before spending time and money on it to convert into an airplane engine. It also needs the exhaust port welded and re machined as the previous owner ran it with a missing exhaust bolt and the muffler wore away the exhaust port! Thanks for the offer on the prop hub but I am going to run both these engines on CDI and will machine up my own prop hub to suit. The Mac is probably going to end up in a boat so I will have to machine up a hub / flywheel and a water jacket. I'm going to machine the cooling fins off the head and weld a water jacket around it.

Rich

on the mac, the spring attached muffler had a gasket, they don't do much after a few years of service, mine was gone completely, once it's to that point it's easy to get out of it's cradle or whatever you want to call it, with the stock unmodified muffler they're a little louder than say a weedeater brand, but not much noise comes out of the 1/4" hole in the thing...

with the two 1/2" tubes coming out of my muffler, it's pretty loud in front of my garage, but pretty quiet at the field...

http://www.rcuniverse.com/forum/m_7837600/tm.htm

The FS 80 is 25.4 (26CC) I fount the FS74 to be 22cc. Nice running engine, Don't like the end play with these but is a strong runner. Check out the Stihl site above.

Thank you, thank you, thank you!!!

That was alot of help and some great ideas! As for the endplay, there is a shim at the end of the crank to take up the endplay, was yours still there? Without it the crank will resonate sideways and hammer the crap out of the bearings!

For those of you using this engine, according to the Stihl dealer, parts for these engines are getting very hard to get hold of as Stihl has stopped making them. I managed to get new crank bearings and seals but the gaskets are no longer available! I didn't dare ask about pistons, rings, etc.

Rich

Question?

Would the 25cc Stihl be a suitable engine for the 68" Gee Bee racer for sale at Tower Hobbies?

Rich

Help!

I need advice, please. Today I cut off the front flange on the Stihl crankcase but I am debating wether to cut off the rear recoil flange and use stand offs or just mount the engine on that flange. Any advice? I don't think there will be any weight savings using stand offs just the added bonus of adjustability.

Rich