Stuck Piston

Hi all, I posted a while back about a piston that is stuck on the con rod (Cannot get pin out). Tried puller, heat, and everything we could think of.
Finally, we decided to split the case and dissasemble, and either press the pin out w/ big arbor press, or just get a new con rod.
Now the problem, the case is split in half, and all of the pistons are still on. But something is catching on the pistons, and we cannot get the pistons to go through the top half of the case!!!
Is there something obvious that I am missing?? It seems that this should work, but something is catching and we cannot see what.
I know that the manual sais to remove the pistons first, but the stuck one is the prob that we need to fix.
Any Ideas??

Sorry, all
77 650B

look at where the bottem of sleeves sit above crank the case is in the way pistons need to come out first.:S

make a pin puller with a bolt and washers use the threads to pull the pin through.

Is the pin bent? number one?

If not, once the retainers are out, the puller should work. I mean the pin went in there. The only interference would be something that will wash off or a burr on the retainer channel that can be cut off.

I take it the big end doesn't fit through the case either...

-Duck

Post edited by: Duck, at: 2006/06/26 16:01

The big end should fit through the case, but the pistons won't because the main bearing webs are in the way.

steell wrote:

The big end should fit through the case, but the pistons won't because the main bearing webs are in the way.

oops i forgot which bike are you working on?650s have 2 piece rods dont they?ive never owned or wor worked on a 650 before ,but thats what ive heard.just unbolt the cap from big end of rod put rubber hose over rod bolts so you dont knick rod journals.and pull the whole rod/pison out the top of cases.thats why steell makes the big bucks around here!

Already tried the puller and all it did was strip and bend the hardened stainless rod! (and yes the retaining clips are out) The bugger is really in there!
I thought from the begining of taking the rod off from the botom, but cant get to it!?
Seems quite a mess?
Thanks for the help, any more ideas, a bigger hammer!, perhaps a jack hammer, or a stick of dynomite!!

Actually I might just have to make a better puller, hardened rod and nut, and fine pitch threads.
thanks

Is the pin binding in the rod or piston?

Is the pin bent?

Will the big end fit through the top of the case if tilted to bring out one side at a time?

Will Dudley untie Nell before the train turns her into wolf chow?

Why can't you get to the crank to unbolt the big end? If you flip the motor upside down the bottom case half should come off leaving the crank in the top half, and the big end bolts right in front of you.
Sounds like the wrist pin is seized to the piston.
Strange

steell wrote:

Why can't you get to the crank to unbolt the big end? If you flip the motor upside down the bottom case half should come off leaving the crank in the top half, and the big end bolts right in front of you.
Strange

To remove the bottom case half on a 650 you need to remove the secondary shaft/starter clutch first, no way around it - the secondary shaft sits in the lower case only and is tied to the crank through the primary chain.

In order to remove the secondary shaft you need to remove the clutch, clutch basket and hub and the oil pump, then remove the secondary shaft bearing retainer bracket on the right (ignition) side of the engine, then remove the bearing cap from the left (alternator) side and tap the shaft out from the left side.

Post edited by: OnkelB, at: 2006/06/27 13:04

I forgot about that :blush:
IIRC, the only way to remove the oil pump is to remove the top case half.
Sheesh, sounds like a "You can't get there from here" situation

Heat the piston and try and push the pin out?

I'm out of ideas