Mark 30 Help

[squirrelboydeluxe]

cpizze1
The 1956-1958 Mercury Mark 30 has long been my favorite merc of all time. I've had dozens of them; incl several 30H's.
As far as your motor's provenence, if you bought it from Aeroliner I would give it my blessing. Their stuff is always top notch.
I set my mains (on the bench) at 1 1/8 turns out from lightly seated and the pilots at exactly one turn out from seated. Just make sure you snug up the packing nut on the mains...I can tell in about 1/2 second it one has loosened up on mine.

Test wheels are not too hard to find for a 30H; I would imagine Aeroliner has a few. They have tons on stuff...also check Outboard Paradise.
Joe Poole Jr (Ferguson/Poole Marine) is not far from you; Joe is a Mercury WIZARD and extremely helpful/knowledgeable
Another great resource for old merc's is the John's Old Mercury website- there are some very sharp guys on there and they will fall over backward to help getting an old merc singing
Feel free to call me at 717 919 4726
522-P

[cpizze1]

Found my test wheel. Next time I get it in the water it will really be helpful. Someone else mentioned timing as well...so I think I will try adjusting the timing too as the throttle opens.

[JohnsOldMercurySite]

these vintage 4cly mercury's are known to stall out when put into gear when the idle mixture is too lean, this being a race motor always in gear and if you had the prop on when starting in water would react the same if too lean, easiest test is enrichen the carbs as previously mentioned by others .... nice ride

[cpizze1]

Thanks for the info. I also found my test wheel so that will help next time I have it in the water.

[cpizze1]

Update!

So I had time to take it to the lake and try a couple of things. First, the was a small air leak in the tank fitting to the fuel pump I fixed. Second, I put a smaller prop on the motor and last adjusted the high speed (slightly) on the carbs. Pulled the first time and ran great! Not the fastest thing around (heavy boat), but ran pretty good!

Thanks "ALL" for the great advise!

Coady

[Guest]

With the 1:1 gears the prop shaft center should be about 3/4 inch below the bottom. A suitable prop would be about 6 1/2" dia and about 9" pitch. The engine needs to get in the 6,500 RPM range to make good power. Looks good on the water!

[Fastjeff]

Nice looking rig. Did you get the starting problem resolved?

Jeff

[DeanFHobart]

Maybe I should give up on the Mark 30 and put the Mark 58 on it.....Freaking thing is heavy with the fishing lower unit on it. I have the down housing but will need a lower unit. I am assembling a cornpopper from a padded 20H block that "Quincy" did back in the 70's. Could do that too.

Your Glen-L TNT is 11’ long so the Mark 58 should be just fine... Set it up so the bottom fo the cavitation plate is even with the bottom of the boat. The higher center of gravity will be different, so just be careful until you get used to it.

Your restorations look very nice.

[Team B&H]

The MK-30 likes a heavy oil ratio. Compared to the other 40 and 44 cubic inch Merc 4 cylinder motors which all use similar crankshafts, connecting rods and needle bearings, the MK-30 uses less fuel and oil per revolution to lubricate the same bearings. To get the equivalent amount of oil that the larger engines ingest, keep ration on the rich side 16 or 20-1 is good. Remember, oil is cheaper than parts- a special engine builder's favorite saying. And its a lot easier to add oil than replace parts. Extra oil will not harm your motor at all. How do I know all this? Experience is a great teacher!