1978 gs 750e cafe racer rebuild

[drivera84]

Turning it the wrong way?
Use the 19mm ignition side bolt. On the end of the crank, on the right side of the engine if you were sitting on it. Small round cover. Remove it. Don't force anything if it really feels like it doesn't want to go.

Pulling a spark plug or four out will help too, as you won't be turning the engine against the compression that way. Motor spins clockwise (forward) from that side.

The whole head is removed...so compression is not an issue, I have a seized piston. Ive tried everything to loosen it up but nothing.

I have time...so Ill just keep spraying on liquid wrench (penetrating oil) and diesel in the crankcase and in the cylinder.

You told me to no force anything...did you mean to remove the engine cover or to turn the crankshaft bolt?

Ill post new pics when I can..

thanks!

[240punk]

I don't suggest doing this but I would hammer down on the piston.

[drivera84]

I don't suggest doing this but I would hammer down on the piston.

LOL ive been tempted to do so....

Ive tried banging it lightly with a wooden block so as not to ruin it...I still hope that maybe I can save it....both outer pistons are on the up position, so I dont really know which one or if both are seized. When dissasembling it I managed to pull the cam up a little bit, enough to relese the two inner pistons. So now I cant pull the cam out nor push it back in...

[pete]

Under that timing cover on the right of the engine where you say there's a double bolt, that 19mm is the one to use to turn the crankshaft like The Cafe Kid says.

The safest thing is just to turn it clockwise, and use a good socket or wrench that won't slip off.

If the pistons move a little then stop, I'd probably stop trying to force it, flip the engine, and split the cases to see what else is siezing it up.

And just be warned that I'm no guru, just trying a common sense approach... there may be better methods...

[drivera84]

hi guys,

Ive been trying to get these pistons to move....nothing!

I have a bearing puller that I think might work...what do you think?

[pete]

Just had a thought... is it in gear? That will make it harder as you'll be trying to move the gearbox as well...

Not sure how the bearing puller will help?

[drivera84]

Just had a thought... is it in gear? That will make it harder as you'll be trying to move the gearbox as well...

Not sure how the bearing puller will help?

Im not sure if it is in gear Pete, the rear wheel is stuck so I cant really move it to tell. I push the shift lever varios times down until it doesnt click anymore and just slightly up....I think it is in neutral but I am not sure.

I havnt tried the bearing puller, but I figure I can get the claws to attach to the jugs. Then put a piece of wood ontop of the piston and skrew the center of the puller see if the piston moves.

[pete]

I think if it was me at this point I'd be pulling that sucker out, flipping her over, and splitting the crank cases...

If you can't move the wheel or the pistons then I reckon it probably is in gear and worst case scenario is the gearbox is in the same state as the pistons.

I think I'd want to know sooner rather than later what I'm dealing with...

[drivera84]

I think if it was me at this point I'd be pulling that sucker out, flipping her over, and splitting the crank cases...

how do I do this? :S

I dont want to just start taking it appart without really knowing what I an unskrewing....Im sorry to sound so ignorant

[pete]

Have you got a service manual? It will go through the process.

It'll be quite different between your 750 and my 450 so I'm not sure what to look out for, but getting the bottom crank case cover off should be reasonably straight forward I would think.

[drivera84]

Have you got a service manual? It will go through the process.

I belive I do...I just have to look for it. Is it also on Cliffs page?

[cowboyup3371]

I belive I do...I just have to look for it. Is it also on Cliffs page?

'

Yep. Right there at the top of his site.

[Hoosier Daddy]

I would think if you used a gear/bearing puller the way you described, you would only break the fins on the jugs. Fins do not take leverage side ways at all.

[drivera84]

Thanks for the heads up HD...i was thinking the same thing....

I think its time to flip er over and take her appart from the bottom!

At this point i feel like I am getting in over my head and abilities...hopefully with the manual and you guys I will be able to put it back together...

[pete]

Mate I'd never done more than change oil and spark plugs when I rebuilt my 450's engine and the only difference between that and yours is that there's twice as many cylinders.

Take your time, measure things properly, and you'll be done before you know it