Looking for manual for 1987 v20 steplift

[spareparts]

that is a 3.7L 165 hp engine. It has the 4" heat exchanger (the good one), and external alternator conversion(some one already did you a favor). The 2bbl Mercarb, and an aluminum manifold with a cast iron riser. first things first, check the gasket between the riser and manifold, it should have one edge of the gasket that goes straight between the mounting bosses, the other side will scallop between the bosses. If it doesn't have the straight edge on one side(indicates what gasket you have) I suggest replacing it with a factory mercruiser gasket. Second thing, do a search for pertronix ignitions, get the conversion kit, you'll thank me and every one else that recommended it later. Set the timing at 4 degrees BTDC. If you can find a large throttle body 2bbl Rochester marine carb off of an 898. 888, 200,230 mercuiser, you will be happy with the swap, if you can find a 4bbl carb/intake/oil cooler setup, you'll be ecstatic. Looks like the charging system has been taken care of. Look around the balancer for signs of anti freeze, there is a weep hle that lets antifreeze out of the cam shaft drive seal starts to leaking, . If it passes snuff, you will have good use out of the motor.

[twhrider2]

Welcome DD... good looking engine,can't add much to what spare and the guys have already said.
I have an earlier model of same engine, as already mentioned find the weep hole in the water pump housing..it's at about 7'oclock on outer edge facing eng. might want to poke a toothpick or soft wire in it to clear any crud that might have it blocked, run engine and check for leaks.
I used the Pertronix II ignition and Fiamethrower II coil. Up sized plug wires to I believe 8mm for hotter coil and gapped plugs at .040.
These engines had some weak points but with modern upgrades, which you already have most of, are strong running and economical especially if you do your own wrench turning. Any questions just ask and someone here will have an answer...great bunch of folks.

[Devildog69]

Hi again. YOu talk about a " if you can find a 4bbl carb/intake/oil cooler setup ". Can you be more specific...part numbers...where I can buy...ect...

Thanks for all your help.

[cfelton]

Hey Devildog, looks like you got a 3.7 Mercruiser. Check EBAY, I just saw two 4 barrel intakes if you're interested. Look up Mercruiser 3.7 or 170, should give you plenty to check out! Good luck!!

[cfelton]

Oh, I think Mercruiser stopped production of these motors in 1989. You can still find parts, just have to shop around so you dont get ripped off. If you need anything specific just ask. I'm sure we can help you find a good deal on it.

[Devildog69]

Good morning all.. First of all thanks for all the good advise. I took it all and went through the motor but not with its hurdles...First of all I shopped around to find part numbers and found BOATS.NET. From there I found all the Mercury part numbers then searched the web for that part. found some good deals... Next, power washed the whole inside of the engine compartment and motor so I could start relatively clean. I removed the riser and changed the gasket that was leaking with the new one (with straight edge and added mercury perfect seal as well. I then removed and took apart the heat exchanger and power washed it and cleaned the inside and installed new seals and clamps. while this was removed I rewired the starter relay and neutral safety switch and removed the starter and had it rebuilt and repainted. at the same time I rebuilt the alternator and had that repainted as well. Put two new belts on as well. I changed the thermostat and gasket, and replaced the temp sensor. This completed this side of the motor. Moving to the other side I switched the ignition to electronic and new coil with new 8mm wires and new plugs.....here is the first hurdle... One plug snapped in the head flush... ****.... in order to get to it I had to remove the riser and exhaust manifold no problem... took three days and a lot of patience to get it out. ended up with a dremel tool cause extractor would not touch it even though I stepped drilled it out to the OD of the threads...I retapped all four cylinders and coated the plugs with never-seize and filled the counter-bore around the plugs with never-seize so water can not collect and rust out the plugs again. Hurdle two...boat has no spark now... Couple of days later and a local marine mechanic on the phone found the problem...shorted tach in the dash. problem resolved and started the boat. IT RUNS.....ROUGH... Rebuilt the carb...RUNS much better.. Hurdle three the riser gasket is leaking???? and so is the Bellows between the riser and the exhaust 3"-4" one. Ordered new gasket and bellows. They came in about a week later and when I was putting the riser back on I noticed the bolts were spinning and not tightening...****.. Heli-coiled the four bolt holes in the exhaust manifold and done.. Boat is in the slip and running. more work to do but I can enjoy it now. Need to get a different carb for sure. The rebuild was a partial one seeing I could not get a couple of parts out. they were still working so I left them. I kept all the parts I removed and put them in ziplock bags and stored them under deck in case I need them.

I can say that I know this engine pretty well now and have a great deal of confidence taking it into the open ocean.

Again thanks for all your help

[bradford]

Good to hear!