1957 Mercury 55E Pistons needed: 726-1612A

Spark691

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Hi I'm looking for pistons (+.015) for my Mark 55E that I'm restoring. Anyone know if quicksilver pistons will work for me if I can't find any NOS Mercury parts? Anyone know where I might get some pistons that will work in my motor?
-David
-Twin Falls, Idaho
 

Laddies

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Re: 1957 Mercury 55E Pistons needed: 726-1612A

Quicksilver is the trade name for mercury parts .015 over pistons for the 40 cu. in engines are like hens teeth. Whats the problem with yours? There are a few used ones around in racers hands they were used in B&D stock outboard. The 20 cu. in. twin cyl. used the same piston.
 

Spark691

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Re: 1957 Mercury 55E Pistons needed: 726-1612A

Well, I got the motor with a boat for $300. I decided to see if I could get it started, since it turned over by hand and the prop spun freely. I got it home and hooked it up to some wiring (the motor's wiring was SHOT, totally corroded) and thence to a battery. It turned over, and over...I got new spark plugs, squirted some oil into the cylinders, sprayed some carb cleaner in the carbs....and it started up!! Bees shot out everywhere from the exhaust...I removed the lower and got the bee's nest out. Then I took the distributor apart...the dist. cap posts were pitted (BADLY) and corroded. The connections to the plug wires were bad too. there was grease and earwigs in the distributor, the points were so pitted they looked like the lunar surface. The fuel filter diaphragm was shot, so I replaced it - found a seal kit and replaced all the seals-some were missing form the old motor! But it ran.

I took the power head off and started to de carbonize the exhaust side...that's when I noticed the piston skirts were somewhat scored and I just figured that as long as I am this far along, I'd try to get some new ones!! Maybe I could just hone the cylinders and use stock size pistons, But If it is at all possible, I 'd like to bore and put new ones. What advice do you have for a first time motor restoration? New pistons or hone and replace with stock size pistons?

-David
 

Laddies

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Re: 1957 Mercury 55E Pistons needed: 726-1612A

Any piston for that engine is highly sought after by the racing community as the engines are being raced in D mod and legal in D stock. You could check on hydroracer, boatracing facts or the antique outboard sites. If you find any new they will be very pricey so clean the cyls and hope that they clean up at std bore, then with a little luck you can find some good used pistons and get rings thru Hastings as the are NLA from Mercury. The blocks are seldon worn out most get scored so light hone yours and check it for out of round and taper, I think you will find it is OK, get back and we will see if we can't help with pistons if yours are bad.
 

Spark691

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Re: 1957 Mercury 55E Pistons needed: 726-1612A

Aye-aye!! I got a compression tester yesterday and I plan on bench testing it today or tomorrow. I'll take it from there. I couldn't believe it ran in the condition it was in...probably hadn't been started since '08 (the last registration n the hull). Now I'm cleaning...and cleaning, ordering some parts like points/condenser. I got a distributor cap NOS!! Thanks for the info on the parts sources. I'm still hoping for some NOS pistons or some really good used ones.
 

Laddies

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Re: 1957 Mercury 55E Pistons needed: 726-1612A

Make sure the cap is gray or tan, the red and green one were not much good. Dwell the points 48 on a 4D mag and 52 on a Fairbank Morse, it should jump 1/2 to 5/8" coil to case just turning it by hand.
 
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