CB750K7 kickstart locked but engine still turns over...any ideas ?

[spotty]

okay, first some background - PO was riding his CB750K7 daily until it made an unhappy noise from the (he thinks) clutch area, turned it off, pushed it home. it would start again but still made some 'odd noises' so he parked it and several years later gave me the bike (so at least it was the right price)

when i got it home it seemed to be seized solid but upon further inspection the engine would turn over whilst being pushed in gear but wouldn't kick over. delving further into things, it turns over with the plugs out and a socket on the end of the crank so at least the crank/primary isn't the problem

next was attack the clutch whilst checking at each stage to see if it would turn over, or at least get the kickstart moving and eventually after removing the whole clutch (finding on the way that there were two metal plates together in the middle of the clutch basket) and finding nothing else amiss, including the kickstart and its gear which moved quite freely once the outer clutch basket was out.

so i put it all back together, checking at each point that the kickstart worked, and finally bolted up the case, connected up the cable and everything seemed fine....then i left it for a while to do stuff to the Vmax

and for no good reason, the kickstart had locked up again

so start again, crank turns over, took chain and front sprocket off and final drive turns, took clutch out again and the shaft that takes power away from the clutch into gearbox (beer has blanked out its proper name for the moment) turns no problem, once the clutch is out the kickstart turns fine and its attendant gear moves the oil pump gear ok. it goes in and out of 1st gear no problem too.
as soon as the outer clutch basket goes back in however the kickstart locks up solid

opinions please....i have since been given another K7 so if worst comes to worst the first one will be relegated to spares and looked into one day (the second one has electrical problems which is why i haven't jumped straight into it and i want to know why this one is such a bastard)
i'm guessing the elec start will be okay as that turns the primary drive directly but for the moment i'm more interested in .......

a) why won't it turn over with the kickstart
b) why did it appear to be sorted then pooped itself again with absolutely no input from me
c) what caused it in the first place
d) what the 'odd noise' was and how is it related to its current state

any ideas? anyone heard of it before? i put in various related phrase things into the search part of the forum and there didn't seem to be anything similar gone into before. if there is and the beer has caused me to miss it then a link would be most appreciated

cheers, spotty

 

[spotty]

posting again to get it back to the top of the list and see if anyone's got any ideas? i've had a few people round who had a quick look but no concrete ideas yet?

 

[Redliner]

Sound really stupid, but statistically it isn't; are you sure it's in neutral when you try to kick it?

I have two CB750 motors on the bench I'll be taking down soon. I can give better ideas once I'm in them.

Could be a snap-ring popped out somewhere and one of the gears is misaligned along the kicker shaft.

 

[spotty]

ta for that, it's definetely in neutral as when i put it in gear (with the clutch out of the motor) it locks up the front drive chain sprocket but in neutral everything turns (again as long as the clutch is out of the motor)

its looking like its something to do (maybe) with the thing that allows the kickstart to engage the gear that turns the clutch (that in turn turns the primiary drive and crank to start the bike) but when the kickstart is released the gear is itself turned by the clutch and then turns the oilpump

if it is indeed that bit, then its a full engine stripdown.......or in my case an engine swap with a topend transplant as the engines go between the two diff bikes (the dodgy one has a good 836 kit and the good engine is only a 750 and we all know theres no replacement for displacement)