mercury 500 thunderbolt difficult to turnover

[berge472]

i just got a mercury 500 thunderbolt 50 hp. not sure where the SN is... but the motor is very difficult to turn. i reconnected the controls myself so not %100 on nuetral but the fly wheel doesnt turn the prop so i think i hjave it in nuetral. it was ran last weekend by previous owner so it isnt siezed up. i thought maybe it was a weak battery so i put in a new one with 625 cca and same results. the starter struggles to move the fly wheel. i tried pull starting but it is too difficult to pull.

any help would be great, thanks

 

[hotrod53]

Re: mercury 500 thunderbolt difficult to turnover

I have a '77 500 Thunderbolt 4 cylinder, it came with an emergency rope so I would assume that it could be pulled, but I'll bet that its tough. Any way to video it so I can compare to mine? Maybe your starter needs serviced, if you have a new battery, there isn't much else that would cause it not to turn over fast enough other then a starter or bad connections.

Don't let taking a starter apart scare you, its a pretty easy job. You will have to take 5 minutes and a pair of tin snips to make a brush holder tool to reassemble it. Not sure how old your motor is, but my '77 needed a little grease on the armature and bushings after sitting for 13 years.

Did you pull your plugs and turn it over?