33Saw Broken drive shaft...

rgvkid

New Member
Sep 21, 2008
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Los Angeles,CA
Damn! I lifted the engine off the tire to tune the carb and didn't think it was a big deal not to take the roller off. PLUNK! while adjusting the High adjustment the roller flew right off the shaft. When i looked at the shaft it ripped the threaded end right off the shaft.

I have a piece of 1"x 3/4 DOM steel bung with a ID of .400 which i drilled out halfway to 13/32. Its slides onto the remaining drive shaft which im planning on welding it onto halfway into the bung. There is very minimal play once sleeved on so i hope i get as straigh as possible so the roller doesn't wobble. On the other side of the bung im going to weld a piece of threaded rod, possibly 10M because it fits super tight in the bung. Once i tap in the 10M rod it will be straight out of the shaft so i can slide the roller onto and tighten down with a nut. The original threaded drive shaft was 5/16 OD, the new rod will be a bit more then 3/8 which will make it considerably stronger.

Question: I found a Grade 8 Left Hand threaded bolt but the bolt stor wants $15 just for 1"x 3/8 bolt, not sure how much the nut was i didn't bother to ask. A Right hand threaded bolt is probably a $1. If i use a regular threaded rod with a torque Nut and lock washer will it unscrew itself when WOT? Or should i just spend the $20 and get the Left Hand threaded bolt? I know its only $20, but hey times are hard.
 

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deacon

minor bike philosopher
Jan 15, 2008
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north carolina
I could never justify that for a nut and bolt. I would use the right handed and red locktite. Actually I used jb weld on the threads of one that I am building. The homelite has a left hand thead on the clutch assembly but a right hand thread on the nut that held the clutch bell to the assembly. I am suing the clutch assembly as a stop and have drilled and bolted a pipe end cap to it. I used the jb weld on the end nut. I'm not sure what it will do but I did ride it one time for a few minutes and it seemed okay. Without the jbweld it flew off the drive.

If I ever try to take it off I will probably screw up the engine but thats the chance I decided to take. I need to know what it will do for future builds.

I had the same thing happen to my 42 engine.. Tell me what kind of tire were you running and is the bike a suspension model. I have a feeling that the road bumps are shocking the roller and that is bumping the drive shaft. Why it doesn't screw up the bearings first is beyond me. But mine broke right at the end of the threads for the clutch. I just junked my engine. I figured anything I did would make it out of balance and it would shake apart.
 
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rgvkid

New Member
Sep 21, 2008
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Los Angeles,CA
Initially when i was building the mount to the bike, i dropped the engine on the concrete and it landed right on the edge of the roller and slightly bent it out of true. So i tapped the other side of the roller and it straightend out fine. Im sure when that happened it fracture the shaft so it was probably going to happen eventually. The tire i has a street tread on the center so its not rough on the roller. I might just wait till i get the Left hand thread and do it right the first time because once i weld it on then its stuck. I don't want to use JBweld because i still want the option to be able to drop the roller size if i want to.

Thanks Deac
 

deacon

minor bike philosopher
Jan 15, 2008
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Thanks for the information Im still trying to figure out what happened to my drive shaft as well. I have a lot of theories and no facts.
 

rgvkid

New Member
Sep 21, 2008
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Los Angeles,CA
Well, the new welded bolt will definitly be Grade 8 or Automotive grade 10. If the next project i do has a 5/16 rod i will probably sleeve and upgrade to 3/8 or 10M just for the peace of mind.
 

deacon

minor bike philosopher
Jan 15, 2008
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north carolina
so how did the 33 bike do power wise... I have to look into a larger engine I have trashed all mine. I am about to finish a 26.9 homelite chainsaw front wheel drive.

I do want one larger engine on a bike to run errands with. So how did you like your 33. I liked mine till it stopped working. I rode it pretty much all over town just had to avoid the largest hills. It might have done okay on them but it quit running before I got a chance to try it on them.
 
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rgvkid

New Member
Sep 21, 2008
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Los Angeles,CA
Well, its been sitting since i broke the shaft and i haven't had a chance to work on it. But the one good 15mile test run that i took it on it seemed to do well in power aside from it shutting down every 10min. or so. Im hoping it was because it was to lean, but until i can get it on the road again i won't know for sure.

There was one big hill i took it one and it actually did alot better then i expected. I did have to pedal assist but it wasn't like i had to stand up and start huffing and puffing at all.

But to be honest with you, I think im just going to save up and go for a Honda GX50 on the rear and mount the 33Saw on the front. I'll let you know how things work out once i can get it back on the road again.

Thanks for all your help Deac.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
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north carolina
Well im not much help but if I can do anything just let me know. What I really liked was my 42 but to be honest it was too easy. Riding a bike should have some elements of the bicycle involved. I mean heck with the forty two it was just a better looking scooter. I hardly had to do anything.

One thing I have been thinking recently is wondering why my drive shaft broke and I think it might have to do with just dropping the ending instead of easing it down to the tire. I'm gonna try to remember to take it easy next time.
 

5-7HEAVEN

Well-Known Member
Aug 2, 2008
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Charles, is your 33 chainsaw engine 2-stroke or 4-stroke?

When planning a dual engined machine, it's easier if both engines use the same gas, be it oil/mix or straight gas, especially if you carry extra gas on the bike.