Lawn Boy 31cc weed trimmer conversion
 

Was given an old Lawn Boy 31cc weed trimmer and this is going to be my first conversion.

First off, anyone know who made the engine? Ryobi? The carberator is on the rear (opposite side to the pull start) of the engine.

I have managed to get most of this one apart. but am stumped with getting the centrifugal clutch off. I managed to get the output bell off (Torx screw down inside square drive) but the remaining clutch portion has me guessing. I did find some posts on removing clutches and most suggest a left hand thread onto the crank. I haven't tried that yet but thought I would take a break before I break something and ask if anyone knows.

Cheers, Graham in Embrun near Ottawa Canada.

RE: Lawn Boy 31cc weed trimmer conversion
 

The Lawn Boy 31 is a Ryobi. Mine was a short shaft and the clutch was at the cutting head. Other than that it was just a Ryobi 31.

RE: Lawn Boy 31cc weed trimmer conversion
 

Thank you kindly, I now know more about it that I did before and every little bit helps.

I am going to assume (dangerous that) that the remainder of the centrifugal clutch is left hand threaded onto the crankshaft. I will give it a try tomorrow.

Thanks again,

Cheers, Graham in Embrun near Ottawa Canada

RE: Lawn Boy 31cc weed trimmer conversion
 

I wish I could remember but it's been about 10 years.

RE: Lawn Boy 31cc weed trimmer conversion
 

Since I starte this thread I should update it with a bit of information that hopefully anyone doing a search will find.

I asked what make this engine was, the Lawn Boy 31CC trimmer is indeed a Ryobi.

I then asked about getting the centrifugal clutch off. After removing the bell of the clutch by removing the philips head screw down the front tube of the bell, the remainder is threaded on the crankshaft and is a regular right hand thread - righty tighty, lefty loosie. To keep the engine from turning over while you are trying to remove the clutch someone in anothe thread suggested using a short piece of nylon rope stuffed through the spark plug hole. I did and it works very well.

Now, how do I remove the flywheel?

cheers, Graham in Embrun near Ottawa Canada

RE: Lawn Boy 31cc weed trimmer conversion
 

Unscrew the nut, (most are standard left hand thread). Then wedge two large screwdrivers under the flywheel; one on each side and pry upward. Then give the crank a smack with a hammer and it should pop right off. It's a good idea to leave the nut screwed on, flush with the end of the threads to protect the crank while you hit it with the hammer.

AV8TOR

RE: Lawn Boy 31cc weed trimmer conversion
 

av8tor1977: It looks like a beach where you fly? Do you fly in other places near also? How about the sand....do you need air filters to keep grit out of engine? Take care....your friend Capt,n;)

RE: Lawn Boy 31cc weed trimmer conversion
 

Yep, flying off the beach is a kick! We also have a 1000' by 500' strip we have the use of, but the beach is more fun. We use a large piece of carpet laid out to start and tune the engines. Then we are just careful to get them rolling a bit at low throttle before nailing it. No air filters and no problems. We've been doing it for quite a while... I have had a few engines apart after crashes and no evidence of dirt ingestion. We're pretty careful.

AV8TOR