Please help, may buy a sleeping Mariner 150 V6

aztecrich

Cadet
Joined
Aug 1, 2009
Messages
20
I am taking the DT140 Suzuki off my bass boat, tired of working on it all the time and having a parts nightmare, Looking at an older Mariner 150 V6 carberated 2 stoke. It has been resting about 4 or 5 years they say, Went out to it today, removed the plugs and sprayed some deep creep in the cylinders, Turned the engine over by hand a few times and let it sit a bit. Hooked up a battery and spun it with the starter, Blew all the excess out of it and ran a compression check on all cylinders, came out as follows, #1-100, #3-102, #5-100, #2-100, #4-101, #6-100, Id like to think this is good. Reinstalled the plugs, pumped some premix deep into the carbs and spun it over with the starter, It actually fired for an instant and got blue smoke out the exhaust around the prop shaft.
Now here is what's bothering me, I think I hear a slight knock in this when spinning it with the starter, Hard to tell with everything going on and the engine not starting. I may be a litte too jumpy about this but don't want to pay the price if I have to rebuld the powerhead.
I couldnt "feel" anything with my hand on the block with it turning over, doesnt get any louder or anything, Im not used to a V type motor and wonder if they all sound like that when cranking.
Any thoughts, ideas, suggestions would be greatly appreciated.
I looked on the one Mariner serial number chart i could find and didnt find this number range under the 150hp's The covers clearly say 150 on them even though the paint is rather faded.
Serial number is 5316614
The only 531's i found showed a 175hp, Please help

Old men just want to go fishing

Retired widower seeks retired widow with boat and motor, Please send pictures of boat and motor
 

Jeff_G

Petty Officer 2nd Class
Joined
May 1, 2005
Messages
179
Re: Please help, may buy a sleeping Mariner 150 V6

So far so good.
With all the plugs out, turn the engine over slowly with a wrench on the flywheel nut 15/16". Check for any roughness.
Unfortunately there is no way to know without disassembly whether any bearings are rusty, seals are any good etc.
The bottom end cap comes off pretty easily for seal replacement and you can check the bearings as well. The top end cap needs disassembly.
You will need to rebuild the carbs, replace the impeller for the water pump, and I would recommend replacing all the hoses and go through the fuel pump as well.

You may want to take it to a good shop and have it checked out.
If the pistons and cylinders are OK you could have the engine gone totally through for under $2K. So keep that in mind.
Good luck
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Please help, may buy a sleeping Mariner 150 V6

After 4 or 5 years it's almost a sure bet that the carbs are going to require a good disassembly and cleaning, then you can run the motor on the boat at the lake/river, then you can determine what it's worth, if anything. You probably wouldn't buy a car without driving it. Good Luck!
 

aztecrich

Cadet
Joined
Aug 1, 2009
Messages
20
Re: Please help, may buy a sleeping Mariner 150 V6

After 4 or 5 years it's almost a sure bet that the carbs are going to require a good disassembly and cleaning, then you can run the motor on the boat at the lake/river, then you can determine what it's worth, if anything. You probably wouldn't buy a car without driving it. Good Luck!

Thanks for your help, Now here's the real killer, I contacted Mercury Marine by phone and gave them the serial number, I was told that this motor does not exist in thier records, Hows that for customer service. They say they have no record on file for serial number 5316614, Guess i best pass on this one, How would I ever get the right parts for it.
Thanks

Old men just want to go fishing
Retired widower seeks retired widow with boat and motor, Please send pictures of boat and motor
 
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