Topic: A little JB weld and this should be OK, right?

[Patrick]

Since I started the glacial teardown of my F3 750 engine I've been wondering what it was that made the PO park the bike until it turned into a ferrite sculpture. The clutch was in excellent shape, and it was installed in the K2 750 engine I installed in the F3 frame (Frankenbike). It's the best clutch on any of my bikes. The shifter mechanism was in very nice shape, although I wish I knew a source for new springier shifter return springs. Every bolt I have removed from the case has been shiny like new. I haven't gotten around to splitting the cases yet, but I really expect to find everything down there in very good shape, based on the nice clean oil I drained from the bike.

Two piston sleeves were masses of rust. So rusty, in fact, that only after I let them soak for a couple weeks did I see this:



So whaddaya think? Maybe some JB weld, clean up the rings and start it up?

Patrick
 

[HavocTurbo]

I'm sorry man... If it's the hole you are referring to...

You need a new piston. Or a very good machinist/welder.

JB weld will not hold up. Period.

[Johnny5]

Is it a hole or a gouge in the carbon? Hard to tell from that picture.

[Sam Green Racing]

I'm sorry man... If it's the hole you are referring to...

You need a new piston. Or a very good machinist/welder.

JB weld will not hold up. Period.

Or a magician. 

[Frankencake]

Slap it back together and start it on ether.  Rev it up as high as it will go and take a garden hose to the intake.  That'll get you to rebuild it.  JBweld be damned.

[HavocTurbo]

Slap it back together and start it on ether.  Rev it up as high as it will go and take a garden hose to the intake.  That'll get you to rebuild it.  JBweld be damned.

haha I just got yelled at for laughing out loud at work.

[Hush]

I think (though I'm no expert) that you will find the air mixture will be greater than the gas so it may not start right up, however enough gas may pond in that clever aftermarket piston crown to allow initial idling.
Refitting the head may help also but I can't be sure.............

[Patrick]

At least I don't have to worry about saving the piston when I pound the top end apart. That piston is stuck to the cylinder wall more securely than Australia is attached to the planet...

And yes, Johnny 5, that is indeed a hole. I'm thinking there might have been a mixture condition during the apparently short time this motor worked.

[chrislib]

This...

is your friend 
if that don`t work try duct tape.