I need some advice

I got the same dilemma! I got a worksman trike that's dying for a front mount. I have a chainsaw engine with a clutch but it looks like I may do better without that clutch and friction drive. But it's on the shelf for now.

I know from nothing about belt drives. If I were going to motorize a trike i would do it just like it did the mtb bike I just finished.

Motor friction drive on the front wheel with a gravity clutch. The gravity clutch I have lifts the engine off the wheel with a brake cable arrangement. You don't have to get it more than a half inch or even less to solve your problems. Thats really all any clutch does is disengage the drive mechanism.

Today I ran the mtb bike around the area where I usually ride the china girl bike. I am using a 31cc engine not a 70cc so there is a little drop in speed and hill climbing ability but it is very very doable as transportation as well as a fun ride.

I would not plan to race it though. Since I just finished the bike i am not sure what to expect long term. I am still learning how to best ride it.

I'm new to this DIY and not familiar with any of these motors...but it would seem to me to be possible to mount a centrifugal clutch like they use for go-karts...espacialy if you want a chain drive.

They have both chain and belt clutch's

Brakes, Clutches, + Hubs | Go-Kart + Mini-Bike Accessories | Go-Karts, Minibikes + Scooters | Northern Tool + Equipment

Are those clutches standard to weed eater, lawn mower or chainsaws.

What's up everyone, I'm jake, new today...

If you decide the weedeater motor is right for you, you may want to check something so simple as to see whether the little metal spring piece in the spark plug cable is in there or not. I had that issue with mine and stuffed alum. foil as a poorman's substitute. I got a complete tuneup on a weedeater for about 70-80 bucks and the guy replaced gaskets, plug, tuned the carb right, fuel line, filter... by that time you may consider a new, application specific engine...good luck.

deacon said:

Are those clutches standard to weed eater, lawn mower or chainsaws.

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No they are not standerd to weed/chainsaw...but I think with a little bit of mod to the shaft something can be worked out....keep an eye out on my DIY build thread....I just might try to get one to work for the friction drive weedeater.

JdubsLBC said:

What's up everyone, I'm jake, new today...

If you decide the weedeater motor is right for you, you may want to check something so simple as to see whether the little metal spring piece in the spark plug cable is in there or not. I had that issue with mine and stuffed alum. foil as a poorman's substitute. I got a complete tuneup on a weedeater for about 70-80 bucks and the guy replaced gaskets, plug, tuned the carb right, fuel line, filter... by that time you may consider a new, application specific engine...good luck.

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I bought a brand new 31cc bolens weed whacker for 75bucks and it make a great bike.

good buy. i admit i had a sick emotional attachment to my craftsman weedwhacker.... or it would have made sense to replace it. haha.

ah I used one of those for a weed eater bike but I let it run out of gas and managed to drag it till it seized. It is now part of several other motors. the joy of cheap engines. It was well used when it came to me.

If you ran out of gas, I guess those little engines would go until they seized that sucks. BTW I am now an elite member. LOL

your toro two-stroke should be a tecumseh 5 horse...it should have a 3/4 shaft, so dave31's right to suggest the centrifugal chain/belt clutches,3/4 is a common size, cheap stuff.the only thing is most centrifugals engage around 2000-2500....what would the toro-two-stroke spin at idle...would it eat up/burn out clutch shoes quick?. maybe set it up like it probably was on the snowblower, with a tensioner pulley and belt drive for the gear reduction and clutch, going to a jackshaft, then to the rear wheels. or go get a COMET 20 SERIES, with a 3/4 driver.your tecumseh/toro should have 4 bolt-holes around the shaft, that protrude about a half inch.these will fit directly to the torque-a-verter comet kit.you can find the kit for around 150.ebay, go-kart sites, theres alot of competition selling these, so a better deal is always there. then you won't need a clutch, or gear reduction, or a bunch of ugly bootlegged crap.comet cvt's are beautiful things, i dont know why i dont see more builds with the 20-series.its adaptable to MANY different brands. these are no bull, they've been around for 60+ years. honda civics even had a CVT trans at one point,1995-something. anyway i have a couple tecumsehs like your's, they sound like dirtbike engines. just take the carb off, take the four phillips screws out of the flat side,take that cover off and theres your diaphragm, snowblowers dont have air-filters, so its probably just dirty.dont tear the diaphragm though, get the cover loose, then use a razor blade to scrape it off, if it feels stuck.might avoid a rebuild kit that way.