Crankshaft Extension for a 3HP??

[oldbugger]

Does anyone make a crankshaft extension with a keyway that would screw into a 3hp that has a 1 1/4 long by 3/4 inch shaft. I do notice that Briggs makes a crankshaft extension but no info of what engine it is for (Briggs & Stratton P/N 691779).
I have been looking for a 3hp with a 2 1/4 inch PTO for about 4 monthes in N. Calif and no luck.
Been running an ad for 4 monthes on Craigslist and called nearly 30 small engine repair shops looking. Can only find 3 hp with 1 1/4 PTO as they are very common here
My application on a bike needs for the clutch to mount outboard and the sprocket inboard hence the long shaft for the clutch keyway that is only on the actual clutch end of the clutch assy.

 

[metal man]

yellow hand was making some . no idea if he has any left or not maybe pm him ?

 

[Txpowdercoater]

just taper the shaft and weld on a piece to the snout, thats what I did to run an extra gear for the blower drive on my mini.

 

[Bill Ellerby]

Briggs p/n 691779 is made for the 283702-286702 series motors. Maybe someone has an old crankshaft thats no good and can cut off the end you need!

 

[125ccCrazy]

not sure if the cranks are the same but I can get a complete 3.5hp locally for $25

 

[Yellowhand]

There are Comet-brand extensions available on ebay...they're actually made to hold a 3" deep driver onto a 2-1/4" shaft, but the principle is the same as what you're looking for...

However; these Comet extensions may be drilled for 3/8" retaining screws, which wouldn't be good for a Briggs crank if it's factory-tapped...

I have a Briggs 3hp I'm running with an extension...make sure you choose a clutch that has a long key and engages as much of the factory crank as possible...a screwed-on extension can't drive a clutch reliably.

 

[oldbugger]

Your right that extension will not work for me. Oh well it was a thought.
After looking at the shaft and how the extension I was thinking about adding would attach it was clear to me that it would not work as planed. I haven't found any clutch mfg that makes a reasonably priced clutch with a full length keyway or any that even makes a keyway that is on the sprocket end (centrifugal clutch). Max torque nor Comet makes such an animal and when I checked with my local machine shop about making a one of a kind extension that I could screw on and then braze.. "We have to charge for our machinist to fabricate that and if you do not have blueprints it will run you $150 an hour, 2 hour minimum as we only build auto racing engines and not toys". Same place that tried to charge me $400 for pressing new bushings for old Porsche (8 bushings), bought some threaded rod and washers etc and pulled them in, took about 15 min to make the tool and about 1.5 hour to pull the bushings.
Anyways probably better off just buying a new crank somehow when I can find what part number to use.

 

[goforthclan]

Did you solve this problem? If so, how? does anyone know where I could get the shaft extension pictured in the above post I saw on here it was available on ebay and couldn't find it. I have also tried to contact Comet industries and have had no luck there either. Any help would be greatly appreciated.