Guys, I just picked up a new to me 1989 75hp Mariner. The motor is going on an 18ft aluminum CC. I cannot read the tag, but I can read the serial on the Welsh plug.
Serial # C204183
From the serial, pulled up the model # 70754129D
Compression was at 120 per cylinder, and Iit started up on the first turn of the key. Its going to get hung in the next few weeks.
I'm open to any particular advice on this motor. Is there anything I should look out for or check?
I appreciate your help.
Last edited by leckbass; 11-26-2019 at 04:14 AM.
Regular maintenance- plugs, gear lube, water pump, fuel filter, lubricate pivot points, inspect fuel lines/bulb, etc.
If you don't have any history on the carbs or engine, you may want to consider going through the carbs and fuel system, then perform a complete sync-n-link procedure. Remember- any FUEL DELIVERY problem is also an OIL DELIVERY problem.
Feed it top-tier 87 octane fuel (89 is acceptable) and if possible, NO ethanol.
Mercury or Quicksilver Premium PLUS oil... Quickare and Quickleen in the fuel.
They were very solid engines for their day!
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Thanks, so far I'm good with the water pump, lower gear oil, and spark plugs. I have not gone through the carbs at all myself, but the mechanic who sold it said he rebuilt the carburetors. I have only run it on a stand, I did not hang it on the boat yet. If I do have any operation issues on the boat then I will go after the carburetors.
Thanks for the heads-up about the fuel filter I will order one of those ASAP.
I was thinking about ordering two fuel filters, I want to put one on the line before the primer bulb. Do you think that will be okay?Originally Posted by EuropeanAM
not recommended before bulb needs only to be after fuel pump where original is or should be
.................................................. ...the scariest thing in life is the unknown ...................................
Seems interesting to me, all of my big boats have or have had a racor style filter.
Additional filters can introduce a fuel supply restriction, which is detrimental to performance and engine longevity.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Thanks for the info, I will just change the filter underneath the cowling, but I'll keep an extra in the boat just in case.
Anything wrong with a fuel / water separated? Had one in my boat , never had any trouble .
Depends on the engine and configuration. In general, Mercury does not recommend "additional" filters or separators for the above reasons.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
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