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Rigging up an Electric Clutch for my Briggs 18hp (42 ci) motor

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clutch electric pto pto pto clutch
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DIYEngineer235

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John Deere 210 w/ Hydro, 317 WIP
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Discussion starter · #1 ·
I'm working on building a Franken317 for use on my property. I purchased it for $50 and a push mower I hadn't used in a few years. It was originally a John Deere 317, but it was repowered with an 18 hp Briggs & Stratton motor. Now, why whoever did the repower didn't just swap over the original clutch is beyond me. It was rigged up with a pulley clutch that seems to work, but won't work for my needs. So I'm stuck looking for an electric clutch for it.

Now, I know the original style electric clutches should work. The problem is, the used and usable, ones are hard to come by and the new ones cost $500+. So I'm seriously considering getting a non-eom (read cheaper) electric clutch and trying to adapt it for this motor. Has anybody done that succesfully before? I was thinking I could rig up an adaptor plate that would let me bolt the clutch directly to the engine.

If I go through with this, what are some pitfalls that I should be aware of? For instance, do I need to worry about the newer, non-OEM clutch being strong enough?
 
#2 ·
The original motor would have been either an Onan or KT Kohler and PTO clutches do not generally swap across differant motors, some bolt onto the motor but others do not..... you will need to find a clutch that, first, is designed to fit whatever size output shaft your B&S has and then possibly do some fabrication to mount it... also tricky because PTOs are tractor specific so any parts store wont be able to find a number corresponding to a 317 with a B&S engine.
 
Discussion starter · #3 ·
Lance Skene said:
The original motor would have been either an Onan or KT Kohler and PTO clutches do not generally swap across differant motors, some bolt onto the motor but others do not..... you will need to find a clutch that, first, is designed to fit whatever size output shaft your B&S has and then possibly do some fabrication to mount it... also tricky because PTOs are tractor specific so any parts store wont be able to find a number corresponding to a 317 with a B&S engine.
Click to expand...
Actually, I know the clutch would adapt across. It's from the same era as the original motor and I did get confirmation that the original clutches would match up. The problem is, the originals are priced around $500 new and used are hard to find. Making an adapter isn't that hard for me.
The shaft size is 1 inch. I figure I can look up engines with similar shaft sizes, including length, and see what works. There seems to be only 3 or 4 common clutches used these days so cross-referencing shouldn't be too hard.
In fact, one of my jobs in my professional life is finding alternative parts sources and I'm very good at it.
 
#4 ·
I would expect an electric clutch to work fine, assuming you can source one w the right i.d. and needed offset.

The main thing for the engine is that it has a charging system that can put out about 6A DC, so that it doesn't drain the battery when the pto is on.

After that, it's just figuring out where to put the anti-rotation pin, so it's out of the way, and, as a nice to have, relatively easy to remove/reinstall if you have a separate belt to say, connect to the transmission, behind the pto.

From the machines I have, if you have a choice, I would pick a pto that had a wider "spot" for the anti-rotation pin, to use a rubber pad to hold it in place, rather than a solid metal pin. I have a Gravely zero turn, bought new, that has a metal pin (which wasn't particularly thick) that I just happened to notice had worn through about 90%, and I removed and welded it up, but that happened after only 3 years of relatively light usage (under 100hrs/year). Alternately, I have 2 Snapper hydro walkbehinds, that use about 1.5" wide rubber pads in the anti-rotation slot of the pto, and they are 20+ years old, used commercially (and recently year round), with no wear on the rubber pads.
 
#5 ·
A huge consideration
Ogura clutch is bi-directional, where Warner style clutches are uni-directional
so make sure you get the correct component, either clockwise (pulley up close to the engine sump, reverse mounted) or counter clockwise (pulley down or away from engine sump, forward mounted), forward or reverse mounted design for mower belt alignment.
CW and CCW are "clutch rotation terms", NOT engine engine rotation terms.
The correct way to tell is where the pulley is mounted....
If the pulley mounts next to the sump (pulley on top), it's a CW clutch.
If the pulley mounts away from the sump (pulley on bottom), it's CCW clutch.
Link:
Clockwise vs Counterclockwise clutch design link:
From Extreme Outdoor Power
Doug Lee
*
 
Discussion starter · #6 ·
dave_r said:
I would expect an electric clutch to work fine, assuming you can source one w the right i.d. and needed offset.

The main thing for the engine is that it has a charging system that can put out about 6A DC, so that it doesn't drain the battery when the pto is on.

After that, it's just figuring out where to put the anti-rotation pin, so it's out of the way, and, as a nice to have, relatively easy to remove/reinstall if you have a separate belt to say, connect to the transmission, behind the pto.

From the machines I have, if you have a choice, I would pick a pto that had a wider "spot" for the anti-rotation pin, to use a rubber pad to hold it in place, rather than a solid metal pin. I have a Gravely zero turn, bought new, that has a metal pin (which wasn't particularly thick) that I just happened to notice had worn through about 90%, and I removed and welded it up, but that happened after only 3 years of relatively light usage (under 100hrs/year). Alternately, I have 2 Snapper hydro walkbehinds, that use about 1.5" wide rubber pads in the anti-rotation slot of the pto, and they are 20+ years old, used commercially (and recently year round), with no wear on the rubber pads.
Click to expand...
Those are some good tips. The B&S I have actually has a two wire alternator. One has a diode and puts out 2-3 Amps DC. The other is 3-4 Amps AC. I figure if I can cut out the diode and wire both to a rectifier, I can get 6-8 Amps DC to charge the battery.

That's a good tip on the rubber bumper. A rubber grommet would probably solve your problem.
 
Discussion starter · #7 ·
Douglas Lee said:
A huge consideration
Ogura clutch is bi-directional, where Warner style clutches are uni-directional
so make sure you get the correct component, either clockwise (pulley up close to the engine sump, reverse mounted) or counter clockwise (pulley down or away from engine sump, forward mounted), forward or reverse mounted design for mower belt alignment.
CW and CCW are "clutch rotation terms", NOT engine engine rotation terms.
The correct way to tell is where the pulley is mounted....
If the pulley mounts next to the sump (pulley on top), it's a CW clutch.
If the pulley mounts away from the sump (pulley on bottom), it's CCW clutch.
Link:
Clockwise vs Counterclockwise clutch design link:
From Extreme Outdoor Power
Doug Lee
*
Click to expand...
Thanks!
I hadn't realized that clutches could be direction dependent. I'll keep looking. My B&S is a horizontal opposed twin and spins CCW btw. The front pto is a 1 inch keyed shaft. It uses a driveshaft off the flywheel to run the hydrostatic transmission and hydraulic pump combo. Fewer pulleys and belts that way.
Image
 
#8 ·
B&S has a pdf on charging. Easiest way to get is is google "briggs and stratton charging system pdf", as the url includes a word that the forum bans, so you would have to manually edit the url to make it work if I posted it here.
 
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dave_r
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