It seems like you have what you need as far as fuel, spark, compression.
though i wonder two things or three. my first thought was its flooding. if its flooded starting fluid wont help. simple is shut off fuel, drain carbs and try and start only with starting fluid or just a bit of fuel mix directly in spark plug hole. do the cats have a engine base drain plug like the polaris fuji engines used to? it allows you to drain fuel that has collected in engine in the event of a severe flood.
2nd thought. your wet plug is water and not fuel. over the years there have been tons of people that have sworn their gas was clean and why wouldn't there sled start. well. maybe its mostly water. you can test in same way as above or run rubber hose from fuel pump into 1 gallon can.(of course you have to drain carbs as well as dry spark plugs first.)
third thought. on the engine locking up when pulling... is something hydro locking your engine.? like water in fuel or too much fuel or coolant fluid (which is also contaminating your fuel mixture) tons of water in the system also makes it look like you have great compression when you actually might not have much.
have you tested your fuel pump? can they leak thru the vacuum line into the base engine and flood everything?
89 indy 500,
96 indy trail touring
88 indy 650 sold
Last edited by jayR; 09-04-2019 at 08:28 PM.