WE HAVE PARTS, SERVICE MANUALS AND TECHNICAL HELP AVAILABLE TIMING, ADJUSTING, AND TESTING OLD MERCURY. Mark 35A-55A-58-58A. This service manual has been written and published by the Service. Includes the use of mechanics' common hand tools and the special Mercury Marine.
Values on the classic outboards are very subjective. I've been given old 4 cylinder Mercs more times than I remember.
I'm also willing to pay a good price for one that I need. Off hand, I'd say they're available for free to $2,000 or more and they're worth whatever you think they're worth.
Lousy answer, I know. However my old restored outboards are not for sale at any price. In my business, I've restored 100s of old Mercs. When the arrive here, they are badly in need of some help. You can take the risk of buying a bad one by running a compression check on whatever outboard motor you buy.
Even if the motor you're considering is in running shape, know the compression of all cylinders so you'll be better aware of the need for upcoming repairs. For instance, if the motor pulls 90 psi on all cylinders, it will run normally, but it is on the wrong side of the longetivity slope. If the motor is running, you can listen for the typical and not unusual (for Mercury) bearing rattles. These motors can run normally while sounding like a threshing machine.
Parts availability for the Mark 30 is surprisingly good. They've gone classic and are desirable. There are several companies that specialize in old Mercs. New restoration stuff like the correct paint, decals, and emblems are available. Their lower units are very tough and not uncommon since they also can be found on Mark 15,20,and 25s.
The driveshaft can be a problem as it is really too small for the motor however it takes a really hard prop strike to snap one. The motor likes to run fast and develops its maximum horsepower in the mid to high 5,000 rpm range. They are not especially torquey and are at their best on a very light runabout like Glen-L's flying Saucer. Be prepared to be your own mechanic or find an old school mechanic who can tune by the seat of his pants. Unless the motor is currently running and there are records of when it was last serviced, budget about $400.00 for a thourough once over including new impeller, fuel lines (from the tank to the carbs) fuel pump and carb kits as well as magneto service. A mechanic who can handle this motor and set it up correctly will probably have alot of grey in his hair although there are lots of young guys who are fascinated by the oldies and have the know how.
Make sure you interview well or you might be wasting your time and money. Most guys interested enough to run a classic Merc become their own mechanics.
There's plenty of literature out there that will lead you through a tune up. Along the way, you'll figure out what makes that old motor tick. Finally, that old Mark 30 is a great outboard motor. I'm having a real learning experience with my '69 Merc 500. So far I have replaced the impellor in the water pump, learned how to time it and set up the carbs and linkage to get it to operate correctly, replaced the flywheel and added a stator and regulator so I had a charging system (motor was not built with one originally), rebuilt the MerControl and repaired the wiring harness, ran compression checks, and learned how to R&R the lower unit and still have it shift properly. Last week I noticed foamy oil coming from a vent in the lower unit that should not have oil coming out of it. I drained the oil out and discovered it had a lot of water in it.
1959 Mercury Mark 35a
I pulled the lower unit and this time I pulled the water pump base out. Ididn't go that deep when I replaced the impellor. I had not run the motor before back then and did not suspect issues.
When I removed the pump base, I could see the drive shaft was pitted very badly and the seal was torn and blown out. I have the Merc Manual so I decided to tear the unit apart and replace all the seals, the drive shaft, and the reverse locking cam.
All the parts were available. I use Crowley Marine as a source. The drive shaft was found on Ebay and is, surprisingly, new old stock. All the gears and bearings looked good and will be reused.
The repair manual and the internet are great sources for information on how to do many things on these old outboards. I also recently joined AOMCI and will use that ORG. As a source for info and parts.
If you are at all handy with working on motors and mechanical things, don't be afraid to try and tackle a repair or restoration project on an old OB. You will learn a lot and meet some new friends. 100-130 for a good used one. 90-110 for a re ringed one (it'll come up after it breaks in) New oversized pistons, rings and appropriate bore job: 110-120. It'll come up to 130-135 with complete break in.
I always look for an original (unopened) block. A lead slug will be wired on one of the intake-block bolts. These are typically missing if the block has been opened up. Quiz the owner about the history of the motor One nice thing about Mercs is the small bore system they used on all their motors.
They didn't use bigger pistons/cylinders as the other outboard companies did when they wanted more horsepower. They used more pistons/cylinders. This kept the bore/stroke on the small/short side and the end result is that a higher percentage of old Mercs have survived to this day. The big pistons of the other guys used will begin to rock in their cylinders when compression begins to take its toll. It's hard to wear out on old Merc 4 banger-most of them die because someone forgot the oil or didn't service his cooling system and blew the impeller. Great news, Charlie!
Can't wait to see it. (Pics please) The good news about manual start Mk 30s is that they're easy to start manually. The bad news is that many Flying Saucers have substantial rear decks that makes reaching the motor difficult. One guy's pictures showed a nice solution-he built a piano hinged hatch in the center of the rear deck that he stepped into for starting. If you're interested in putting electric start on your Mk 30, let me know. I sell used Mark parts on e-Bay. I may have the flywheel (one with teeth) right now.
Mercury Mark 35a Outboard Motor
Unfortunately, I don't have a good starter motor. However, I'm always on the lookout for Mark 30,55,58 as well as the Merc 300-500 series which have flywheel/starter combinations that'll work with your motor. Assuming plenty of time between now and your launch, I should be able to help if you're interested. Thanks guys, I am stoked about getting this motor. I don't think you many are sale in my area.
In fact the guy I got it from purchased it off e-bay out of Washington state. I got a feeling as we were doing the deal he still didn't really want to part with it. Randy, yes I am interested in adding an electic start. I already have the flywheel with teeth as he included one with the purchase but would be interested in a starter.
One of the first things I need to do is build a good stand for it. Second is find some controls to work with it. Here are a couple of pictures. If you go with the old two handle controls, I'd get some with the cables attached (or at least the cable ends included) as the ends are hard to come. There are OMC cables, (I think they are) that can be modified to work with the early ends, but I haven't found out which ones they are.maybe Randy can shed some light on this.
I think it would be best if you bought a set with the switches and harness to get the proper switch and harness ends.new wire can be spliced in between.Not sure if the switches and harness are available for that control. Here's one I bought off E-Bay that was used with a manual engine with a rare control mounting bracket. (I think.I've never seen another one) They were normally mounted through-bolted through the control. An electric start one would have the choke and ignition switches near the bottom on one side.