Clutch Question

#1
What am i missing here? Thought i better ask before "Gettin Western" with it.
3.5hp Tecumseh. Set screws are loose, i can't see any marks on the "carriage bolt or?" like it had been put on with a pair of channel locks or vise grips?

Not sure exactly what I'm seeing here. The washer is lop-sided, makes me wonder even more. So i thought i would ask the gracious gurus that bail so many of us out or save us from doing stupid...
Thank you old mini-bike forum!
 

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#4
Oh, I didn't realize that was a bolt. Lol. The bolt should have a head so you can get a wrench on it. I guess vise grips or channel locks to get a grip. People did weird things 50 years ago on these bikes.
 
#5
They still do wierd things today! o_O

That's why i was asking, no bolt head, no plier marks on the edges, nothing.
Set screws come right out no issue. Looking at it i thought i would ask before gettin western with it! Lol
I do have a Metabo with a 1/16" cut off wheel, not afraid to use it! ;)
 
#7
I'm guessing it was tightened with Channellock or Vise-Grip pliers, the pliers likely slipped, cutting away/smoothing any "teeth marks". I think I would grind two opposing flats into the bolt head (don't worry about grinding into the $0.03 washer) and use my big (Special Occasion) Channellocks on it!
 
#8
That i can not answer definitively. I'll have to have to look and see to be able to answer that intelligently. It'll be a couple days before i get back to the shop.
 
#11
I think i see what you're looking at. Might explain why the washer is lop-sided just a bit.
I'll get a better look at it tomorrow evening. I would think there would be a keyway on the crank. Would there not be by chance? Were there ones made that did not have a keyway?
 
#12
I think i see what you're looking at. Might explain why the washer is lop-sided just a bit.
I'll get a better look at it tomorrow evening. I would think there would be a keyway on the crank. Would there not be by chance? Were there ones made that did not have a keyway?
Yeah, it looks to me like the key may be a little too long and it bent the washer when the bolt was tightened.
 
#13
My bad posted this was as a 3.5 Tecumseh, in fact it's a Briggs.
With that said, it raises a cpl more questions.
Got the clutch off, cpl pair of Channel Locks and i got the Carriage Bolt out. Still don't know how the PO got it on there w/o jaw marks, or better yet why use a carriage bolt?
A 3jaw puller made quick work to get the clutch off.
From the face of the clutch to the pto shaft (.625 x 1.625) was 3/4" of an inch. Is this normal? Seems like a lot if dead space to me?
The carriage bolt is 5/16" x 18 is this normal or would it be metric? I screwed a 5/16 bolt in. Seemed loose?
The key looks like it was sheared off. Yet didn't find and remnants in the cavity.
Next at i looked the clutch (max torque) over i notice the wear on the sprocket, replace or run with it? I'm thinking replace it.
Sorry to ask all the dumb questions, yet i was told a hunert yrs ago the only dumb question you ask is the one you don't... 20210130_143345.jpg 20210130_143311.jpg 20210130_143908.jpg 20210130_151532.jpg 20210130_154344.jpg
Thank you OldMiniBikes I'm proud to say i belong and support this forum!

Mark
 

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Biffmini

Well-Known Member
#14
My bad posted this was as a 3.5 Tecumseh, in fact it's a Briggs.
With that said, it raises a cpl more questions.
Got the clutch off, cpl pair of Channel Locks and i got the Carriage Bolt out. Still don't know how the PO got it on there w/o jaw marks, or better yet why use a carriage bolt?
A 3jaw puller made quick work to get the clutch off.
From the face of the clutch to the pto shaft (.625 x 1.625) was 3/4" of an inch. Is this normal? Seems like a lot if dead space to me?
The carriage bolt is 5/16" x 18 is this normal or would it be metric? I screwed a 5/16 bolt in. Seemed loose?
The key looks like it was sheared off. Yet didn't find and remnants in the cavity.
Next at i looked the clutch (max torque) over i notice the wear on the sprocket, replace or run with it? I'm thinking replace it.
Sorry to ask all the dumb questions, yet i was told a hunert yrs ago the only dumb question you ask is the one you don't... View attachment 274569 View attachment 274570 View attachment 274571 View attachment 274572 View attachment 274574
Thank you OldMiniBikes I'm proud to say i belong and support this forum!

Mark
you have a few issues there. replace the clutch, it's not worth repair.
your shaft is shorter than needed for correct clutch installation, about 7/8"short
Id get you clutch with a built in key & install shaft the bolt with a 7/8" spacer of some sort.
 
#15
Biffmini: Thank you 4t he reply Sir, that confirms the original thot when i got it apart. Except for the clutch with a built in key?
It's a Max Torque clutch I believe the sprocket is replaceable?
Now the dead space of the shaft would have to be hollow to allow one to bolt the clutch on, should that be keyed as well?
Thank you,
Mark


Or throw $99bucks @ it and prol'um solved! Lol :D
 
#16
Yes, the replacement sprocket is $23. I'd replace the bushing as well for $8. I have fiber washers if that is bad. I use a little jig for the job- wood, a drilled hole, and some screws per Max Torque video on rebuilding them. So we're up a tad over $31 to repair that clutch to be as good as new. I've done some experimenting on spring tension as well:

These mini bikes/clutches were designed for 12 year-olds running 3 HP lawn mower engines. Now that 60 year old fat asses are riding them, the clutches are inadequate. Slap in a green spring, raise the RPM for engagement, and get that same 3HP rush that you used to get in 1972! :)

As far as the engine PTO being too short, get yourself a 3/4" keyed jack shaft, and cut it to fill the space, and run a longer key. You can bore it and thread it to mesh with the existing PTO as well. Not an issue for the clutch, and cheaper than replacing the crankshaft.
 
#17
These mini bikes/clutches were designed for 12 year-olds running 3 HP lawn mower engines. Now that 60 year old fat asses are riding them, the clutches are inadequate. Slap in a green spring, raise the RPM for engagement, and get that same 3HP rush that you used to get in 1972! :)
Hey now HD i totally resemble that remark! Lol :D

Ok i got what your sayin. Easy Peezy. The gut was leaning that way, thot I'd ask B4 doin sumffin I'd regret! Like trash the little guy toting my Fat Arse around!
I'm just trying to make the little guy stand tall again...

Now I'll hit Hent up on Flea Bay and see if he can work his magic on it!
Thank you all for helping me, i understand more and more of that which i do not know tkx to all the help from y'all (OldMiniBikes) i read everything posted. Learn alot, now if'n i can recall it when needed is the question! :confused:
 
#18
Hey now HD i totally resemble that remark! Lol :D
Me too. I've lost 30 pounds, and I'm still a fat bastard, and wish I were still sixty, if nothing else, because it's a nice, round number, easy to remember, short term memory being what it is. :)

I'm just trying to make the little guy stand tall again...
Ha! Aren't we all!

About the green spring. I was very impressed with how much more rider friendly stock, lower horsepower machines were. Check out Jim Donovan's video on rebuilding the clutches. I've made some special tools over the years to drive bushings and such, but it's a very rewarding operation rebuilding your clutch. especially when you see how much better it performs. I'm more than happy to help in any way I can.
 
#19
Yo Dave STOP looking search is over, found the 30# ya lost!
Yes sir just blew by the 60 mark w/o even slowin down.
In my world everthing is short, including memory!
Yeah bout that little guy standing tall! :scooter: lol

I will watch his (JD's) videos and pick-up parts from Hent on Flea Bay for the clutch upgrade plus whatever else i gotta have. Thank you 4the insight. Greatly appreciated Sir !

I'm always up for tools, huge plus if i can make'm!
 
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