I bought an engine a few months ago advertised as needs rebuild, got time today to have a look at it,the flywheel will turn about half a turn, I popped the valve covers and the valves all move freely what are peoples thoughts may be the problem its a type 4 1800
Wd 40 down the plug holes , gently turn back n forth noting if it goes further each time , I would expect it is slightly rusty bores I’ve got plenty running like that without a strip down
Whip the plugs out and make sure their are no obstructions. Wd40 is actually surprisingly good for this as other typed. Meths is also not bad as it evaporates faster but has less and I mean a lot less lube in it. Clunk means something is stuck Scraping noise means it rings on the barrel
If it is pistons sticking we used to use boiled hot diesel down the bores left to soak a few minutes and then have another go at rocking them gently on the crank! I know I’m old and haven’t done any serious engine work for donkeys years, but the principal is still the same.
while you have the engine out its easy to work on take the heads and Barrels off and inspect the bores for wear and check the rings and little ends for play drop the sump off and check the crank and big ends for wear!! couple of hours work if its been advertised as needing a rebuild you will soon see what needs sorting IMHO if you bodge it up and run it you will end up stripping it down anyway.
Ha Ha yes mostly rebuild classic motorcycle engines but used to own a Beetle a while back and refurbed the engine on that among others
Sorry my Bad you would have to split the crankcases to inspect the big end and crank DOH !! The point I was trying to make was it's not a good idea to try and run an engine without finding out what is wrong with it