Can't get Crank or pistons out......suggestions?

[michaelart]

I have a 760 yamaha core.....that I have partially disassembled.....I have managed to get all the bolts out.....removed the head and removed the bottom half of the crankcase..... problem is I cannot get the crank and pistons loose......the cylinder walls do not appear to be that bad.....but the crank is rusted and corroded.......any suggestions? I have attempted several methods.....but I need suggestions.....:banghead:

 

[sflsurfrider]

send it to SBT

:haha:

 

[sflsurfrider]

j/k...

did you try penatrating oil around the pistons? sometimes you need to hit the pistons with a hammer and block of wood while someone else holds up the cylinders. sometimes you need to drill a series of holes across the pistons to let them collapse in on themselves. thats an extreme case though.

 

[michaelart]

The thought had crossed my mind.........seriously.........but after recent events I'll have to pass............for now.......ur2funny.......but not the first to say......lol

 

[michaelart]

tried the penetrating oil and hammer/wood on the pistons......I am thinking the issue is more with the crank......it is rusted/locked up mofo.....I was thinking that maybee if i bust the rods at the crank....I could at least get the cylinder and top crank half separated which should be easier to get the dayum parts loose.....

 

[keefer]

Do like SFL said and use a block of wood, oak if you have a piece, and drive the pistons down. You will at least get the pistons out and the cyl off of the crankcase. This will let you concentrate on getting the corroded crank out and not damage the case top. Good luck:banghead:

 

[vomitspot]

mike bring it to me
i will cut the rods w/torch
then put the cylinder into a press and pop the pistons out
jason

 

[waxhead]

Do the pistons move at all ??
if not then its the pistons stuck
If you can get some movement its the crank
if its the pistons i would heat the pistons and get them to expand when they cool down again they shoudl have broken the corrison agaisnt the cylinder wall

 

[SUPERTUNE]

I use my smoke wrench too in cases like that! Do what Jason said!

 

[michaelart]

Sure thing.....just waiting for verdict from the doc......

 

[vomitspot]

good news michael
got it all apart
with alot of cleaning i think you will be able to the cases and the cylinder
even honed the cylinder for ya i think 1st over will clear it up
jason