welded cranks

[rock]

I am looking at an attempt to change bearings on a welded crank motor. Tohotsu I think. If it is built the way the owner tells me you have to cut the crank to remove bearings. Is this correct info and/or has anyone done this. Thanks

Rock

[Dave Strong]

The ones I have seen press apart, then use jigs to press back together to get the timing just right.

Dave

[rock]

Are they indexed somehow or are the jigs for that.

Rock

[Chaz]

If they are like a motorcycle crank , use a square and scribe alignment / witness marks in the cheeks of the sections .
Back in the day all we had was a piece of 6" pipe with a slot cut thru it for the little end of the rod to stick out . drop the crank in the pipe and use two pieces of 3/8ths flat bar like it was a bearing puller and push it apart in a press .
When going back together use two feeler blades as stops to get your side clearance.
Then spin the crank in a lathe or V-blocks . Use a brass hammer and wedges to indicate it back to the last .001 - .0015
Or send it to Tom Falicon on the west coast of Florida .

[Dave Strong]

We have done what Chaz says on a 6hp. Not sure if it's still running or blew up, never heard back.

Dave

[1BadAction]

We have done what Chaz says on a 6hp. Not sure if it's still running or blew up, never heard back.

Dave

So it's running then...

[Dave Strong]

So it's running then...

OR his is so mad he won't come back. lol

Dave

[johnboy 88 vegas]

Sound like a pita to me....unless you have the proper tools for the job or just time to kill....lots of time

[Capt.Insane-o]

I was pretty good at the small triple yammies. You need a squeaker tip and a big brass hammer and a chunk of lead to tweak them in.

[JPEROG]

Charlie's advise is the best advise. Falicon did all of our 3 cylinder snowmobile project cranks. If the pins have already been welded then he will grind the welds, press it apart, replace the bearings and reassemble, press it together, set the timing phase, balance and re-weld it. For what they charge, you can't beat it-and it will be right. They were always great guys to deal with (I am guessing that he did 200 cranks for our group over the years).

Joe

[H2OPERF]

You don't have to but i was told and did on my cr was to cut right thru the rod and crank pin (if the rod is bad) to get the thing apart, this makes it easier to properly grind off the welds and press the pin pieces out. Worked for me may not be the norm. dave

[Chaz]

You don't have to but i was told and did on my cr was to cut right thru the rod and crank pin (if the rod is bad) to get the thing apart, this makes it easier to properly grind off the welds and press the pin pieces out. Worked for me may not be the norm. dave

Flat rate mechanic's sho~do know how to make money .....

[Dave Strong]

Flat rate mechanic's sho~do know how to make money .....

It's all good till ya f%$k it up and have to fix it on your own time. Good flat rate guys know the difference between fast and accurate.

Dave

[H2OPERF]

No sure how to take that but it sure seemed better to press the pin halves out using the rod face boss rather than trying to support the crank around the rod, made pressing the pin pieces out nice and square supporting the crank cheek full circle. . Dave

[Chaz]

No one here is pointing fingers , just sharing what they have learned ...




I usually don't **** up .... but when I do , its throwin itself out of the machine ..