Mercury Black Max 150 info

[SuperNova]

Hi guys, I just need to put my mind at ease or open my eyes. I'm looking at a 1987 Wellcraft V-20 steplift cuddy cabin boat with a 1987 Mercury BlackMax 150 hp outboard on it. It is one of the "clamshell cowl" models. It been sitting for 4 or 5 years now, suposedly winterized properly. I tried to start it (after I cleaned the scum off the top of the starter shaft so the gear would engage the flywheel) and the thing turned slow at first, then after getting fuel into the engine, it cranked a lot freer but showed no inclination to start. I hit it with just a little bit of starting fluid and it fired and ran for a second or two with tons of heavy white/light blue smoke. I think the smoke is just from the fogging oil, and I didn't try any harder to get it to start...at the time I just wanted to make sure it cranked and attempted to start. They want 2500 for the boat, a 2005 loadrite roller trailer and the motor. Seems like a decent deal, but I can't afford to have to hang a motor on it.......any thoughts?

 

[CharlieB]

Re: Mercury Black Max 150 info

When considering any used outboard purchase, you want to test spark on each cyl using a 7/16 gap spark tester to ensure each cyl ignition is functioning correctly. A motor will fire and run with one or two dead cyls, and still sound good.

While testing the ignition you can also test compression on each cyl. Numbers should be well within 10% of each other and near 120 psi.

Pull the gearcase drain screw and get a couple drops of oil to see if it is clean or contanimated, to get an idea if the gearcase has been maintained. If you have a mini-vac/pressure tester you can pressure and vac test the gearcase thru the upper oil vent plug.

Plan on replacing the water pump, rebuilding the fuel pump and carbs.

These few tests should help with your decision to buy or not.

 

[j_martin]

Re: Mercury Black Max 150 info

Yer getting a pretty good deal if the boat is sound. The engine in good shape is probably worth 3 grand or so.

Never spray starting fluid or carb cleaner into a big 2 cycle engine. It doesn't have any oil in it. The fogging oil probably saved yer bacon this time. Also never even pop it off without water for cooling.

If it sounded even when it was cranking, (a low compression cylinder is heard as a skip) and it fired when you sprayed some fuel at it, I would assume the fuel system is all gummed up and the rest is good.

New hoses, fuel pump kit, carb kits, and fuel filter, and of course a water pump impeller, and yer good to go for a coupla hundred in parts and labor, which you can do yourself if you have a shade tree.

Another thing to do is to start it up on 50:1 fuel for the first time, just in case the oil pump froze up in storage. Sometimes they do.

hope it helps
John

 

[SuperNova]

Re: Mercury Black Max 150 info

Thanks to both of you.

John you were a lot of help to me on my Mariner 150 so I just want to say a special thanks again.

I didn't try to run it without water.....we had it hooked up the whole time. But it didn't run long enough to see if it was pumping or not.

I also didn't fire it off the ether right off the bat, I cranked it with the throttle wide open and the choke button held until it started turning over faster and freer. The cranking did sound even, but I know a compression test would be the proof, unfortunately I may have screwed myself out of the deal even by fixing and verifying as much as I have already. They were talking stupid about not selling it if it was in that good of a shape. I told them they could keep it if they wanted and I could bill them for my time......all in a jokng manner.

This motor seems pretty similiar to my 89 Mariner 150 2.0, just the cowling is different. The mariner's cowling was one piece and this engine it's two halves. Why?

 

[j_martin]

Re: Mercury Black Max 150 info

Thanks to both of you.

John you were a lot of help to me on my Mariner 150 so I just want to say a special thanks again.

I didn't try to run it without water.....we had it hooked up the whole time. But it didn't run long enough to see if it was pumping or not.

I also didn't fire it off the ether right off the bat, I cranked it with the throttle wide open and the choke button held until it started turning over faster and freer. The cranking did sound even, but I know a compression test would be the proof, unfortunately I may have screwed myself out of the deal even by fixing and verifying as much as I have already. They were talking stupid about not selling it if it was in that good of a shape. I told them they could keep it if they wanted and I could bill them for my time......all in a jokng manner.

This motor seems pretty similiar to my 89 Mariner 150 2.0, just the cowling is different. The mariner's cowling was one piece and this engine it's two halves. Why?

Let me give you a clue. If I coveted that rig, I would have let them try to start it, noted the symptoms, especially if it seemed to crank evenly. If it cranks evenly, and thumps like it has some compression, everything else if fairly easy to fix. Even if they fogot the kill switch, I would not help them except to recommend water supply to prevent damage.

Then I would bargain for a good price for a non running possibly junk motor, waving a relatively small amount of cash in their face.

Then I would tow it home, do a compression test to verify basic soundness, then systematically service it to top health, probably 250 in parts and a coupla afternoons of wrenching.

This motor is the same except it has a 16 amp alternator on it. (40 flywheel guard won't fit under a clamshell)

 

[SuperNova]

Re: Mercury Black Max 150 info

Let me give you a clue. If I coveted that rig, I would have let them try to start it, noted the symptoms, especially if it seemed to crank evenly. If it cranks evenly, and thumps like it has some compression, everything else if fairly easy to fix. Even if they fogot the kill switch, I would not help them except to recommend water supply to prevent damage.

Then I would bargain for a good price for a non running possibly junk motor, waving a relatively small amount of cash in their face.

Then I would tow it home, do a compression test to verify basic soundness, then systematically service it to top health, probably 250 in parts and a coupla afternoons of wrenching.

This motor is the same except it has a 16 amp alternator on it. (40 flywheel guard won't fit under a clamshell)

Thanks and duly noted. The problem is not sneaking away with a good motor....I truly don't mind paying what they are asking, as much as I couldn't afford to get burned. And there was no way they were budging on the price....they priced it as if the motor was questionable.....that's why I think I may have lost it. I would have just bought it and towed it home, but Pa. has Blue laws that don't allow vehicle purchases on Sunday. So we couldn't have gone to a notary. They seemed like nice people, I'm hoping they are. And when I got to it, the starter wouldn't even engage the flywheel to see if it cranked evenly. If it had actually fired and run, I would have paid for it with a check and towed it home then gone back and done the paperwork.

 

[SuperNova]

Re: Mercury Black Max 150 info

Well, they finally called around 5:30. She swung by the notary and all her paperwork is good for the transfer. All systems go for tomorrow afternoon or wednesday....looks like I got me a new boat (project).

 

[BLU LUNCH]

Re: Mercury Black Max 150 info

You might want to take a look here the home of the V-20 guru's..............
http://www.wellcraftv20.com/

 

[SuperNova]

Re: Mercury Black Max 150 info

You might want to take a look here the home of the V-20 guru's..............
http://www.wellcraftv20.com/

Was there already...didn't register or post, but a lot of good info. Nothing that really helped other than to confirm that a lot of people really respect and love these V-20's....which is good.