[reclinedrelic]

There is no oil pump adjuster bolt. Are you thinking of the cam chain tension adjuster bolt?

Welcome to the forum. Tell us about your bike;year, model etc. Pictures even better.

By the way, visit the wiki, link in my signature, and download a copy of the factory manual for your bike. The answers to most questions are there.

 

[reclinedrelic]

I have a cx500 e trike from 1982 im in tamworth staffordshire

Do you mean that the trike has an engine with serial number beginning CX500E- ? That is a different beast than a CX500E. See here for a list of frame and engine numbers. Honda CX400 and CX500 Engine and Frame Serial Numbers

 

[reclinedrelic]

So, camchain adjustment becomes an engine-out procedure. Brilliant!

I think that it looks like the hole may have been widened? If so a rear cover would be needed to work with the proper bolt.