Mercury 800 worth fixing???

[Dennischaves]

A coworker had this motor in his shed for the last 20 years he finally decided to let go of it and offered it to me for free he said it was running and winterized?
I dont see a tag anywhere so
Anyone have any idea what year it could be?
The flywheel turns so is it worth trying to get it to run ?
What should i do befor trying to start it?
And anything to look out for?
Are parts still avalable ?

 

[jerryjerry05]

If it turns then it could run.
​Did he say why it was put away?
​Remove the plugs, a quick shot of WD in each hole and do a compression test.
​Somewhere on the motor should be a silver freeze plug with a # in the center.
Maybe OG12345678 something like that.

​The blue band cover, I think was made in the 80's Not positive??

Yup lots of parts out there.

 

[Dennischaves]

It came from a estate sale it was on a wooden boat

 

[Chris1956]

It has a distributor, so I think it is early 70s. Serial number should be on transom clamp. You can look up the year (and parts) with the serial number.

 

[spoilsofwar]

I had a 1970 merc 800. Ran well once I went thru it. The wiring on these motors tends to go bad; insulation is brittle and cracks off. I replaced pretty much every wire in the thing. Something for you to consider if you decide to freshen her up.

From the graphics, I'd say it's a '72 model. The graphics were red until that year, in 72 they became blue.
Www.discontinueddecals.com/mercury_decals_80_19721

 

[Dennischaves]

Theres no number on the transom clamp
Its gone
If i rebuild the carbs am i gong to have to adjust the timing?

 

[Donnyb83]

I have a 1978 mercury 800 80 hp. Looks close.

 

[Donnyb83]

Actually just looked. Mine is a bit more faded. Lol. So maybe a couple of years newer.

 

[racerone]

Fairly hard for the plate above the transom clamps to be gone.---Covered by dirt maybe ?

 

[jimmbo]

Spoilsofwar is correct, it is a 72, the only year the merc 800 had a cowl like that. A 71 would have red stripes, in 73 the engine was modified and became an 85hp
72 was also the last year the name Kiekhaefer appeared on the faceplate
Well at least the cowl wrap, lower cover, and faceplate are 72 vintage...

 

[GA_Boater]

Serial numbers are between the clamps, large circle, older Mercs also have the SN stamped above the distributor, smaller circle and a less definitive way is to flip it over to look at the starter for a manufacturing date stamp. The starter date stamp may not be correct because starters can be swapped out over the years.




I would do the compression test suggested by jerryjerry05 as a first step.

 

[gm280]

To answer your question about keeping it and making it run. My answer is YES! If it isn't locked up, I would do a compression test to give you an idea of the condition it is in. With part still obtainable and it being free, you could spend a little money on it and come out with a really nice running quality engine. But I like doing that type thing and therefore I am biased to repairing and keeping it myself. JMHO

 

[Dennischaves]

I currently have a motor on my boat my plan was get this running and keep it as a back up
So i should compression test then rebuild carbs and water impeller?
When i do the carbs will it mess with the timing

 

[GA_Boater]

Carb rebuilds won't affect timing.