info on a 1979 20hp mercury

[carl0099]

im thinking of buying a 16foot alum smokercraft jon boat with a 1979 20hp mercury. boat and motor are in great visual shape.neighbor is original owner that has gotten sick and cant use no longer. i did a compression check and it was 130 on the bottom and 125 on the top . its only been it saltwater a few times . do you think the motor will last ? dont know much about boats give me your thoughts. thanks

 

[latin monkey]

Re: info on a 1979 20hp mercury

if you use it in saltwater be sure to flush it out with fresh water when you're done. change the impeller every year and keep up regular maintenance and that motor will last a long time

 

[carl0099]

Re: info on a 1979 20hp mercury

thanks latin monkey. so it sounds like this is a pretty decent motor then? even though it's a '79 u think it still has some life left in it? also do you know anything about the compression? are those numbers okay (130 on the bottom and 125 on the top)?

 

[latin monkey]

Re: info on a 1979 20hp mercury

yes the compression looks good. as long as the carbs are adjusted right and it has good water flow it should be a good runner

 

[carl0099]

Re: info on a 1979 20hp mercury

also what kind of oil should i use to mix with the gas ? any brands better then others??

 

[strato08]

Re: info on a 1979 20hp mercury

I have just taken my father-in-laws jon boat with a 79 20 h.p.. New to do some maintenance on it. What are the spark plug #s for champion and the size socket I will need to remove. Any tips for changing the plugs? What is the cap setting? It' been a while since I have worked on a merc. Will change the lower unit oil and grease everything. Only about 120 hrs on engine, just been sitting out covered for a year. Will pull plugs and pull hand crank by hand to make sure good lube. Any suggestions?