My prop adapter has come loose twice I have red local tight to try it has the lock tab washer fitted.looked through the site and see other people have had similar problems just hope it works track day booked .

is there no room to get a bolt to the other side of the prop adaptor and fit a a ni lock nut?

I did this of ln my zx10r engine and never had the issue with this and red lock tight.

Thanks and best of luck

Is it shimmed so the prop adaptor is tight against the nut or bolt that holds it on?

When I replaced my engine Andy Bates recommend that it not be shimmed tight as this could cause the prop adaptor to work loose. As such, I have a small gap between my prop adaptor and the bolt that holds it on. This gives some float at the end of the prop adaptor but so far has remained tight. AB recommended that some float is normal in the original application of a sprocket on the bike and with a correctly specced prop adaptor material will not cause any wear issues.