why do people shave the pto shaft?

The.MiniTard

The.MiniTard

Member
#1
#1
So i'm getting around to firing up my 4 hp and I noticed that the pto shaft is shaved and has no keyway....it has a threaded hole in the shaft, which is something i havent seen with my smaller briggs engines.
Why on earth would someone do this to the shaft and ruin it for a clutch? Can I still run a clutch on this engine or am i wasting my money buying parts for it?
 
The.MiniTard

The.MiniTard

Member
#3
#3
shaved into a taper.....it has no keyway. im confused as to if this was from factory like this(no keyway). the taper is DEFINITELY not factory done.....tool marks all over it
1514309840081.jpg
 
CLH

CLH

Active Member
#6
#6
Some engines came with a female threaded hole in the end - some didn't. Just depends on how the manufacturer of whatever XYZ product needed the shaft to be to work for their application. The cast iron Tecumseh 7hp I have didn't have a threaded hole in the end and I had to take it to the machine shop to have it drilled larger and tapped out. The hole was there on the end - but inside of it were no threads which was incredibly odd/inconvenient.
 
The.MiniTard

The.MiniTard

Member
#7
#7
CLH said:
Some engines came with a female threaded hole in the end - some didn't. Just depends on how the manufacturer of whatever XYZ product needed the shaft to be to work for their application. The cast iron Tecumseh 7hp I have didn't have a threaded hole in the end and I had to take it to the machine shop to have it drilled larger and tapped out. The hole was there on the end - but inside of it were no threads which was incredibly odd/inconvenient.
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what are my options to get this shaft in order to be used on a mini bike
 
CLH

CLH

Active Member
#8
#8
The.MiniTard said:
what are my options to get this shaft in order to be used on a mini bike
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If your shaft is tapered with no keyway I wouldn't bother trying to fit it to a minibike. There are adapters that fit onto tapered shaft to make them non-tapered, but those atleast require a keyway. You can try swapping out crankshafts from a parts motor, but thats a good amount of work and you have to worry about the interchangeability of seals/bearings and if the flywheel will fit when you start swapping out crankshafts. It will be cheaper/easier to find a different engine that has the correct shaft.
 
Fantic Freddy

Fantic Freddy

Member
#12
#12
If you're really in love with that engine, a machine shop could eliminate the taper and cut in a keyway. I think most would agree, the cost would outweigh the value of the end result.
 
S

SAT

#13
#13
I would have to check the total indicated run-out at the future clutch location on the crankshaft before anything. If its bent or otherwise worn, it might be a parts engine. That crankshaft has had a tough life so far. If its good, I would cut and weld, or take it out, cut a keyway and tap the end for a clutch.
SAT
 
TWM1963

TWM1963

#14
#14
That's a brilliant answer! I love it. That's what i shall do! Weld it on. BINGO! [MENTION=13654]gumpit[/MENTION]
 
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TWM1963

TWM1963

#16
#16
massacre said:
Just make sure you weld it on straight with a taper it will be easy to get it crooked
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the shaft on this one is straight no taper. It is threaded and has no key way. I'm almost positive at this point it is idiot proof. But I've been wrong before. I will double check everything before i weld it. Thanks for the heads up. Trent
 
65ShelbyClone

65ShelbyClone

Well-Known Member
#17
#17
The.MiniTard said:
Why on earth would someone do this to the shaft and ruin it for a clutch?
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Because they're hacks without the means to do things right. That's all I can think of.

Can I still run a clutch on this engine or am i wasting my money buying parts for it?
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Depends on whether the shaft is close to a standard size. I'm leaning more toward "waste of money" than anything else.
 
TWM1963

TWM1963

#18
#18
Wow! Wondering why he didn't give his opinions when those post were made in December 2017. Numb from the neck up??? Lmao!!!! I have a low tolerance for stupidity!!!! smh!
 
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massacre

massacre

#19
#19
TWM1963 said:
the shaft on this one is straight no taper. It is threaded and has no key way. I'm almost positive at this point it is idiot proof. But I've been wrong before. I will double check everything before i weld it. Thanks for the heads up. Trent
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I’m sure you will be fine, I was referring to the OP
 
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