Seized Engine 1982 KZ750 CSR (M1)

My first thought was the return spring on the kickstarter too, but some of the symptoms didn't seem to agree.

The kick starter sprocket is permanet in gear with the sprocket of the 1st gear of the in- and output shaft.
As soon as he remove the clutch springs (pressure) from the clutch pressure plate the outer clutch basket has no power/torque flow to the inner clutch hub.
All parts now move free as normal.

Those photos of the broken 750 trans show everything perfectly. I wonder what happened to that bike (I see the broken gear, but why) ? Maybe something similar to Duckinfumb's bike?

I was thinking the kickstart locked up first gear, but then he said the bike can roll in first gear with the clutch lever pulled.so first gear is not locked up. If the bike can roll in first gear, and the engine can turn, then the clutch should be able to turn the crank.

That's why it makes me think there is something with the clutch or the transmission's input shaft (which is the inner clutch basket's shaft). Maybe a shift fork is out of place.? I'm stumped.

It would be nice to know if the clutch inner basket moves as it should and does not have excessive end play, but his photos show it to look pretty good.

Duckinfumb wrote: I went back out and put my clutch back together, threw it in first, and I can roll it backwards with my clutch engaged. ... I can go as far backward AND forward doing this as I want to.
My kickstart swings with an engaged clutch as well, idk if that matters

I wonder if he could see it by removing the oil pan? Maybe not. At that point it might be easier to drain the oil, pull the motor, mount it upside down, and remove the lower case. That's a huge pain in the ass but at least he doesn't have to disturb the cylinders or head. It would be a shame to do all that and find it's something simple with the clutch or shift fork.

I took the pressure plate completely off and nothing wiggles at all. Everything is secure, and rotates smooth.

As soon as I start tightening the pressure plate back on, everything gets real tight and locks up. I took the kickstart plate off and everything looks 100% in there also..
What would cause my clutch to lock up as I tighten the spring plate springs and screws?
Matt

Can you tell if it's the inner basket or outer basket that seems to be locking up?

Only the inner basket moves at all.
I didn't know the outer basket was supposed to move. It's completely locked up now knowing that it is.
Which means when I put my pressure plate on and the baskets switch pressure, it's my trans that's locking everything up?? Am I close?

The outer basket is chained to the crank and could not move.
The inner basket (hub) has to be move free if the clutch is disengaged by the clutch hand leveler or disassembled.
If you pull the clutch lever the the push rod lift the pressure plate and disengage the power/torque flow between the inner hub and outer basket.

So what could be stopping my input shaft from rotating?
As soon as I start screwing in the pressure plate the clutch hub starts locking up.

As soon as I start screwing in the pressure plate the clutch hub starts locking up.

This is normal, you put pressure on the friction plates (hooked to the outer basket) and steel plates (hooked to the inner hub)
The clutch push rod disengage the pressure of the clutch springs and let the outer basket turn around the inner hub (don´t turn if in gear with the transmission/wheel).

This Ducati dry clutch Video Show the release mechanism in Action.

So then it's my primary chain that's locked up? The bike is in neutral with the clutch release still taken apart, shouldn't my primary chain be turning as I rotate the kicker?

Duckinfumb wrote: So then it's my primary chain that's locked up? The bike is in neutral with the clutch release still taken apart, shouldn't my primary chain be turning as I rotate the kicker?

That's the puzzling thing. The primary chain and outer clutch basket move with the crankshaft and you said the pistons were moving so all of that should have been moving with the pistons and crank.

Are you 100% it's actually locked and not just stiff? I know the rear wheel locked up while you were riding, so there's definitely something that needs fixing, but at the moment are we sure everything is actually locked up?

I can crank it using the rotor bolt on the left. If I tighten my pressure plate down even halfway I'm not strong enough to turn it by hand anymore.. Something is causing my primary chain/input shaft to get harder and harder to rotate as I put my pressure plate on, untill I can't move my kicker anymore. At that point my screws and springs are barely finger tight.