1974 20 hp Merc 200- worth fixing or not?

[ozarkzander]

I have been lurking for a long time but now it is my time to post I guess. You guys all amaze me. Anyway, I have a 1974 20 hp Merc 200 serial number 3757666 (I didn't realize the last digits were 666 until after I bought it or I might not have). It has not worked according to the previous owner for a couple of years. I took it to a marina and they checked the usual things. turns out that the low speed stator coil is bad and a couple of other things, less major. the problem is they checked the compression and it was 120/110. The price they quoted me to do everything was a little too steep for me. I figure I could probably do it myself. but with compression like this would it be worthwhile to? or is it just a matter of time before it is going to be too bad to work? Do you think the lack of oil in the block for a couple of years while not running could cause these low numbers?

Thanks in advance.

 

[dkonrai]

Re: 1974 20 hp Merc 200- worth fixing or not?

it depends on if your plan is to hang on to the motor? the compression is low. i have a 7.5 that has 130/128. i am contemplating the same issues on two motors.
i would check the compression myself, then squirt some oil in the cylinders. see if the compression comes up. the problem with these motors is i think the compression chamber is all in one, as in no head gasket? ignitition items are expensive and time consuming. got picts? how is the lower unit? is there spark only on one cylinder?

 

[jbjennings]

Re: 1974 20 hp Merc 200- worth fixing or not?

There's lots of those motors with good powerheads and bad lower units. dkonrai gave you good advice on all counts, so ditto from me, too. I'd look at the lower unit and if it has clean oil in it (it will be a miracle if it does), then keep an eye out for a good parts motor with a bad lower unit. There's lots of 'em like that. The mercs had mild steel drive shafts until they went to stainless in 1976. They were prone to pitting when they get older and the seals go bad. I personally don't think it would be worth it to restore one unless it had excellent compression and a fixable lower unit at the very least.
Good luck,
JBJ