Topic: frozen piston pins

[egar]

Any suggestions on removing the piston pins without hurting the pistons or bending the rods? I removed the clips as per manual but cannot tap out the pins. I've been spraying them for a week with lubricants. Maybe find or fab a little press to pop them out? I'm the guy rebuilding the 70 750 on the shop site.

[bwaller]

A piston pin removal tool protects the piston. You could make something with some threaded rod.

[Caseygroh1]

slide the cylinders back onto the pistons to just above the pin. this will protect the pistons and prevent the rods from bending. they should tap out now that there is something holding them in place. always works for me.

[Toxic]

slide the cylinders back onto the pistons to just above the pin. this will protect the pistons and prevent the rods from bending. they should tap out now that there is something holding them in place. always works for me.

That's a pretty neat trick right there.

A little heat on the piston from a heat gun usually works for me.

It doesn't usually take very much heat at all.  The pistons being a completely different alloy than the steel pins, they expand quicker than the pin.  Or so it was explained to me.

[egar]

Casey,
Great idea. Thanks.

[egar]

My piston pin puller from cb750 supply came in today and I immediately ran out to the garage to try the tool on piston one. I used the appropriate sized end piece (it came with a larger and smaller one) and tightened it to the point that my hands hurt from straining -- and the piston pin did not budge! I feel like I may have wasted $28. Does anyone have any other suggestions? I did remove the clips beforehand so I know that isn't the problem. How could the pins be frozen so tightly onto the crank arms? The pistons themselves wobble to and fro freely.

Ed

[Hannibal Smith]

If the motor was in tip-top shape, and it is the same setup as my CB550, then technically you should be able to push them out with your pinky-

Was your motor abused before you got to it?

[egar]

Update: Strangely enough, the piston pin came out, albeit slowly when I tried pulling it out from the opposite side. The rods have a lot of surface rust from years of sitting, so I guess I'm not surprised.