No need to remove the crank.

[Oldsalt]

Some time ago I mentioned that The PTO side of the crankshaft can be turned and keywayed without removeing the crank from the engine. I had done it in the past but I got the idea that no one believed me. So here we go with pictures.

I was given a dirty but low hours 3 HP Briggs the has a 5/8" threaded shaft. Also the body of the shaft was .005 over 5/8". There of course was no keyway. Impossible to mount a Comet clutch. The shroud was removed so the starter side so the crank could be chucked up in a 3 jaw. See picture. A hunk of wood was screwed to the base of the engine block so that it would not spin with the crank. The spark plug was removed. The oil in the engine and the gas in the tank were not removed. First the end of the crank was drilled and tapped for a 5/16 bolt like normal shafts. Then the tailstock with a live center were used to support the shaft and then it was turned to .001 under 5/8". After that the engine was put in the mill and lined up correctly with a dial indicator and a 3/16 keyway milled. Note the pair of Vice-Grips that is used to keep the shaft from turning while cutting the keyway. The clutch fit just fine. It is too bad that so many good engines have funny shafts and to make them right it takes a lathe and a mill. But sometimes it is possible to at least avoid having to completely disassemble the engine.

 

[dave dickson]

That's A neat trick, SALT, but can you do that with a bigger hp briggs, got 2 or 3 of them tapered shaft motors on a shelf, waiting for someone that can do that, I have 4 heavy go-cart frames, that are waiting on these motors of might, I'll have to pick out the clutch size, and i wouldn't mind taking the thing apart and just sending the cranks, I'm asking as a fore thought of what's to come later this summer, as I've got my hands full with my 9 bike 1 tryke build, right now, and May I'm busy with the flowers, But I'd like to have them back sometime towards the end of June, I think I'll be building 2 to keep, and 2 to sell, anyway SALT, if you could do it let me know.
dave

 

[ogygopsis]

YOU AMAZE ME SALT!! Ogy.

 

[Oldsalt]

That's A neat trick, SALT, but can you do that with a bigger hp briggs, got 2 or 3 of them tapered shaft motors on a shelf, waiting for someone that can do that, I have 4 heavy go-cart frames, that are waiting on these motors of might, I'll have to pick out the clutch size, and i wouldn't mind taking the thing apart and just sending the cranks, I'm asking as a fore thought of what's to come later this summer, as I've got my hands full with my 9 bike 1 tryke build, right now, and May I'm busy with the flowers, But I'd like to have them back sometime towards the end of June, I think I'll be building 2 to keep, and 2 to sell, anyway SALT, if you could do it let me know.
dave

No problem with doing the cranks on even larger motors, without removeing the crank, but a bigger mill than mine will be necessary. The operation requires an extension piece in the collet of the milling machine so that the crank can be reached without the bigger diameter "quill" being in the way. In the case of the 3 HP briggs a "DR" set of collets and extension. A larger engine, bigger than a 3 HP Briggs, would require a larger mill than the one I currently have set up in my little shop. But if you wish to pull the cranks out of the engines and send them I will turn then to the propper size and put the keyways in them. And tap the ends if that is also required. No charge. But first make sure there is enough shaft length to get what is needed to hold the intended clutch. It is a very simple job to do them if they are out of the engine and there is enough metal to start with. I live in Walla Walla WA [yes, there is sucha place] so shipping is expensive if you live on the east coast.

 

[alfalfa]

Could you do this with just a drill press?

 

[dave dickson]

Now alfalfa, don't you know that a drill press is not made for that kind of operation, We here at OldMiniBikes would never even consider useing a tool to do something it wasn't intended to do! that's like useing a screw driver to do the work ment for a chisle, and that little green guy:thefinger: I think that guy should be used for someone in the group who beat you out of a sale on e-bay, not someone of SALT'S experience and knowlege, my son in law is from long island, too, he has no idea where the oil & anti-freeze goes in my daughters jeep, just how to put gas in it!
dave

 

[Oldsalt]

dave I'm pretty dumb about a whole lot of things. But not so dumb about things that interest me...such as mechanical things. Experience? That come with just being lucky enough to grow old. Anyone can operate a mill and a lathe if they really want too. The hard part, of course, is accquireing the tools. That can take a long time if ya ain't rich.

 

[dave dickson]

I see the little green guy is gone!
Back where I come from it is improper to raise the finger to anyone, let alone raise it to an elder, just proper manners, and myabe I'm getting old too!
dave