ST1100 No compression

schlep1967 said:

Before anything else you need to check if the valves are bent. It may be more cost effective to replace the motor.

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+1. I'll be surprised if the valves aren't bent and/or the piston crowns aren't damaged. Hope I'm wrong though.

Do I need to do a valve clearance check to know if they're bent?

Outside of pulling the cams to seat all the valves and then doing a leak test on each cylinder, you could buy a cheap borescope and look for damage to the piston crown through the spark plug hole.

If the valves are bent then the valve clearances will be all over the place but always greater than spec, as the valves won't be seating properly and so sitting further into the combustion chamber than normal.

So I spoke with a buddy who organizes a local bike club and was a mechanic for 15 years or so.

Mentioned:
leaking coolant
shredded belt
zero compression

he said it was a water pump failure that subsequently stripped the timing belt causing engine failure and likely bent multiple valves

:-(((( I'm looking at used engines on eBay. I just don't want to get rid of this awesome bike