No shaft threads for Clutch

[Jrturbo]

What do you do in the case an engine has no threads for the clutch bolt? I was looking at an older 3hp tecumseh but it has no threads to hold clutch. Any advice would be greatly appreciated. Thanks

 

[Moedog07]

You could find a clutch with set screws? I have used those in the past.

 

[Havasu Dave]

Check this out. Small Engine Crankshaft Drill Tap Guides 5 8" 3 4" Tecumseh Briggs Clutch | eBay

 

[CarPlayLB]

drill and tap the crank. Easier said than done, but doable! OldMiniBikes used to sell a fixture for that. I dunno if they still sell it. PM minibikin (Chad). I have one and it works great!

 

[Havasu Dave]

You could find a clutch with set screws? I have used those in the past.

New Max Torques wont be supplied with them, according to Jim.

 

[Jrturbo]

If i go the set screws way, will those hold? I'm sure drill and tap is the best way to go. Thanks

 

[Havasu Dave]

If i go the set screws way, will those hold? I'm sure drill and tap is the best way to go. Thanks

Yes, plenty of hold for a 3HP. It still sits on a keyway, so the set screws just hold it in place on the shaft.

 

[Jrturbo]

Thank you everyone for all your helpful input. Thanks :smile:

 

[Moedog07]

I think the key holds it from turning on the shaft and the set screws keep it from walking around on the shaft.

 

[Beal]

Ive had a clutch slide down the shaft that was just held by set screws, Id almost hate to do it, but what about slathering the shaft with some loctite?
I have a nice running 5hp briggs that isn't tapped I was thinking I might be better off selling.. but if I cant still mount a clutch to it and it would stay that would be cool.

 

[CarPlayLB]

Ive had a clutch slide down the shaft that was just held by set screws, Id almost hate to do it, but what about slathering the shaft with some loctite?
I have a nice running 5hp briggs that isn't tapped I was thinking I might be better off selling.. but if I cant still mount a clutch to it and it would stay that would be cool.

Those untapped Briggs 5HP are junk...want to sell it to me?

 

[george3]

Does it have the pilot hole on the end of the crank? #10 Tek and fender washer will work just fine. It has no pressure on it. Not as clean as drilling, but easy. I make my own jigs for them kind of jobs, but the tek screw will work just fine.

 

[Moedog07]

Drill a hole in the shaft and run a cotter pin or a bent nail to keep the clutch on... :doah: :doah: :doah:

 

[bigrob]

Does it have the pilot hole on the end of the crank? #10 Tek and fender washer will work just fine. It has no pressure on it. Not as clean as drilling, but easy. I make my own jigs for them kind of jobs, but the tek screw will work just fine.

As per George's post , the screw/bolt whatever need not be very heavy or even that well centred on the end of the pto
It just has to be a limiting stop to keep the clutch from floating to far

In theory if the engine pto shaft and j/s or rear axle are in exact alignment plumb and parallel , then the clutch should find its own sweet spot and not need any locking

 

[Havasu Dave]

In theory if the engine pto shaft and j/s or rear axle are in exact alignment plumb and parallel , then the clutch should find its own sweet spot and not need any locking

:thumbsup: Rob, that is what Jim at Max Torque is talking about. The kart racers keep them loose enough on the shaft so they can self align. Easier on the chain, keeps alignment better, and great for those old ass bikes with rare and expensive warped wheels and hubs.

The same idea goes to jack shaft sprockets where snap rings grooves are machined in to retain the sprocket and allow some travel.

 

[markus]

I'm surprised they are doing away with the set screws entirely, at least all the pre-'70 smaller tecs that came stock OG on bikes were 5/8 and NOT drilled and tapped shafts. I realize that market is slim and letting the assy float more is a good idea an all though, They are probably sick of the calls and complaints blaming the clutch when it was a simple setup alignment issue.

 

[Havasu Dave]

I'm surprised they are doing away with the set screws entirely, at least all the pre-'70 smaller tecs that came stock OG on bikes were 5/8 and NOT drilled and tapped shafts.

They are doing away with them. :thumbsup: I've quoted this here before:

Right from the Max Torque Website.

The standard clutch is no longer drilled and tapped for set screws because they are not needed. You never fix both sprockets in a locked position. Only the axle sprocket needs to be in a fixed position. A clutch must be able to float on the crankshaft so it can self align.

 

[Sixpac440]

Cranks are cast steel and as such they drill and tap pretty easy.

We did this a bit ago in this thread .... http://www.oldminibikes.com/forum/tecumseh-engines/108396-crankshaft-tap.html

 

[jeep2003]

cranks drill and tap pretty easy they arnt hardened or anything the ones iv done. Have a second guy look at it from the side while you look down on it drilling and you can get it pretty straight.

 

[Beal]

Those untapped Briggs 5HP are junk...want to sell it to me?

I couldn't possibly knowingly send someone junk. That's just mean! :laugh:

Come to think of it, I also have an 8hp briggs that isn't tapped...