1974 9.8 hp mercury heats up

[JC1933]

Hi I have this motor that heats up water impeler<br />seems good but no water at pee hole please help. J C

 

[emckelvy]

Re: 1974 9.8 hp mercury heats up

Either the powerhead is silted up or the rubber grommet which seals the upper end of the water tube to the exhaust plate has squeezed shut.<br /><br />You can pull the cover on the end of the block, where the spark plugs are, to see if there's silt buildup impeding flow. If you don't find a lot of deposits, apply air pressure or a water supply to the water tube (with the lower unit removed) and see if you get flow up into the powerhead. <br /><br />If not, the grommet is likely bad and you'll need to remove the powerhead in order to replace the grommet. Very common problem especially on motors operated in salt water.<br /><br />Coat the grommet with Permatex #3 aviation gasket dressing for a good seal and to prevent future salt buildup.<br /><br />HTH.........ed

 

[JC1933]

Re: 1974 9.8 hp mercury heats up

Thanks Ed for the reply,will check this out. J C.

 

[SBellew]

Re: 1974 9.8 hp mercury heats up

You can pull the cover on the end of the block, where the spark plugs are, to see if there's silt buildup impeding flow.

Sorry to bring such an old topic back to life, but if you pull this cover, does it have to have a gasket or something to reseal it when you put it back together? Sorry, I am new to marine engines and having about the same issue with my 110 9.8HP.

When I took the 'flush' screw out, there was some dried out red looking dirt in there, but I was not sure how much jabbing I could do to clear it out without screwing something up. Just found out my year so I do not have a manual yet to assist with such projects.

 

[emckelvy]

Re: 1974 9.8 hp mercury heats up

Zounds! I was looking at the "July 5" and didn't notice the date, thinking "can't remember posting this yesterday!" Talk about a flashback to 2004!

Anyway, yes there is a gasket between the block and the cover. Most Merc dlrs should have one in stock.

If you can get a chunk of fine wire up the "flush" passage, it's not going to hurt anything.

Note that when you're removing the cover, if the bolts don't come loose with normal force, you'll need to heat them up with a propane or MAPP gas torch (Lowe's or Home Depot amongst others). The bolts are easily broken so be careful. A little heat usually works wonders in breaking them free.

If you don't find a bunch of gunk in the block, the suggestions in the old post apply. It's very common to see a squeezed-shut grommet blocking flow.

HTH & keep us posted.............ed