Cranking problem

I need your help.....
I have a 1956 registered Trike made from the frame, engine and front end of a XJ900f. Been trying to get it on the road for some time now.... Have had the engine running, gears shifting etc just trying to solve a minor brake issue on the rear axle (non XJ related)..... Then this week rode the trike up the road to check the brakes..... Engine stopped, no skid or noise or smoke, just stopped then wouldn't start..... Well actually wouldn't crank over!

I have tried the following;

a. Jump starting from larger battery - didn't crank
b. Bump starting but wheels just skid
c. Removed starter to see that it spins - yes.
d. Isolated solenoid and fitted it direct to starter and excited it- worked as expected, starter span.

So what actually happens.... When I try to start the engine, the power goes to the starter but then just doesn't spin, you can feel the torque present but it just doesn't turn the engine, almost as if it is in gear - which it isn't.

I'm lost, confused my head is telling me seized engine!!!! How can I tell? Gearbox problem maybe? Don't know.

Is there something simple I've overlooked and how can I turn the engine over by hand I've taken the two small covers of and one has the electrickery stuff and the other (RH Side) just a black rubber seal or plug (not sure which)

Is there any additional check I can do to check the starter motor? It doesn't spin 'really' fast so quite surprised at that! Also doesn't throw out, no longitudinal movement at all.

I can see a cog in the starter motor mounting aperture which only turns one direction freewheeling but solid in other

I have raised my rear axle off the ground put bike in gear and turned the rear wheels...... Wheels turn but drive shaft doesn't. Hmmm actually this is starting to sound more gearbox related..... I think.

I am now at my wits end, grrrrrrrr.

Anyone any ideas.

 

No, but some information that might help with diagnosis:

The engine can be turned over by hand via the large, (19mm) square protrusion on the timing rotor on the LH side of the motor (where the electrickery stuff is.) You can use a 19mm open-end wrench or an adjustable, just be careful not to crash into the ignition pickups.

Turn the motor counterclockwise when viewed from the left (the same direction as the wheels when moving forward.)

The starter DOESN'T "throw out" its gear; it stays engaged to that gear inside the motor that has the one-way clutch. That's the infamous "starter clutch."

If the rear wheels turn but the drive shaft doesn't, pull back the rubber boot where the shaft meets the motor and see if the shaft is TRYING to turn.

It's possible that you have a really big hunk of disintegrating primary chain guide lodged in the gearbox preventing it from actually going into neutral.

 

Right...... so next thing to try will be to turn the engine over with the 19mm protrusion on left side.

Does the clutch need to be pulled in during any of this?

Incidentally, 'I think' I've read it somewhere that there is a starter cut off for the side stand and the clutch but as mine is a trike no side stand and up til now I've not needed to engage the clutch to start it.

Regarding the hunk of alien material in gearbox, not sure if this is the problem as I can place trike in neutral and it will free wheel, then when a gear selected trike won't roll and or should I say but doesn't turn over the engine, even took the spark plugs out to make it easier.....this is the bit that worries me!

Will update the thread when more is known but still think it might be something simple..... Or something really bad!!!