TOPIC: Merc MK 55 Floats and Recoil Starter Lube

I think I found the culprits! My Merc MK 55 would run good for a few days. Then would start to leak fuel out the throat of the carbs and run rotten. I took the carbs apart and found cork floats. Aha!
Fuel logged floats. Now I put in new replacements Black plastic From East Coast Marine.
Now since I have the top cowl off I think I need to lube up the recoil starter. It is a little sluggish.
Any ideas of what lube to use?

That is a real sweet looking Mark55!
I use FluidFilm, PB Blaster, or I suppose WD-40 would work fine.
The grease on the dogs gets 'dried out' over time & heat transfer, and consequently the dogs and the disk have too much friction.
You can also spray one of the mentioned products into a small hole where you can see the spring and get it working a bit smoother too.
Use something that doesn't dry out with heat.
If you want to take it all apart you can use a graphite base lube on the spring and a light grease like Power Punch on the dogs & disk.
If you haven't done one of these rewinds in the past though I would suggest simply using an aerosol lube as mentioned.
As soon as you apply the lube repeatedly operate the rewind assembly to get the lube worked into where it needs to be before installing the unit.
I also wait a couple hours after I lube the unit so that the excess lube can ooze away and be wiped up before it gets a chance to slime your powerhead too badly.
Thom

Thanks Thom,
I'll use the aerosol method. I'm sure that will get things running smooth again. Will keep you posted onthe Merc
This motor is the manual start model and still has the wire seals in it. Ran pretty good until gas logged floats.
I'm also working on my 62 Homelite. Bill Roberts is helping me with that. Parts and advice.

Dave, if you've ever had one of those springs jump out at you while attempting to take it apart for "service", you'd appreciate T's good advise even more! (We didn't have forums back in the day, had to learn that one the hard way. - haven't taken one apart since.)

Good luck with your projects.

Yes Mark, I don't like taking recoil springs apart. I have enough trouble with those that are used on Briggs & Stratton lawn mower engines.

One thing else you might consider to eliminate future fuel delivery problems is to replace all the original fuel hoses and replace the fuel pump diaphragm kit.
The alcohol-gas today breaks down the inside of the original Merc hoses.
For a Mk55 I would use push-on fittings and new 1/4" I.D. fusl hose.
If you only have one fuel pump,...You will need (4) straight fittings 1/8"NPT male x 1/4" push-on, (1) 90 degree 1/8"NPT male x 1/4" push-on, (1) 1/8"NPT male x 1/8"NPT female x 1/8"NPT female. And,...The fitting needed at the quick release is 1/4"NPT male x 1/4" push-on.
The brass fittings may 'break the bank', but will be a permanent fix.
Thom

Thanks Thom,
I'll look into that also. I got a nice 14" pitch prop I want to try on it. Right now there is a 12" on it. But I think the 14" will work fine on the Mirror Craft. Also got a nice 9" 3 blade brass that would work if I put it on a big heavy boat or ponton.
Riiight now I use that for decor in my living room along with a nice vintage bow light illuminated with a night light. Flag staff and all. Like this one. I have a Lone Star Flag on it

Dave, all the fuel fittings and hose Thom listed are very similar to what I needed on my '62 700 FGS. I found a local fitting supplier that also carried marine fuel hose, and walked out the door with everything for right at $60. The O.E. hoses were still available at THAT time, but would have totaled around $80 as I recall. I also used the spring type clamps on all the hose fittings, just for insurance.

Sta-Bil also has a new MARINE formula out, claims to fight the damaging effects of the 10% methanol gas. Since you cannot find any of the Good Ole gas around here anymore, I've decided to try it. Hope I'm not throwing my money away, but almost all the experts agree that alcohol and older outboards are not compatible.

Love the bow light, that's awesome! I've got a period correct stern light I'll give you if you ever want to sail your coffee table at night.

I have a clamp on stern light for the coffee table. LOL
Runs on a D" battery.

I have a 62 700 FGS on my Lone Star Fleetwood.

love the 700. even though i don't use it much it has never failed me. when i got it back in 2004 all i did was install new fuel pumps, plugs,and water pump. have not had to change the plugs yet. ron

I love my 700 also.
I got mine in 2005. Had to put water pump impeller and lower seals.
Ran great until I was playing with different pitch props and blew a rotor by too much RPM. Still working on that problem. Back together now but spark on only 3 cylinders. Points or something. Just have to tear back into it.

The Merc repair manual scared me so bad on the distributor on the 700, I haven't even taken the cap off it! I messed with a few Mallory dual point distributors back in my hotrod days, but this one looks complicated beyond that. Have you checked both (I believe it has two) condensers? They're sweet old motors, when they're running right. Good luck with it, wish I were more help.

I have to admit. I have a helper who has worked on these before. And yea, After reading the manual it is scary. I haven't went solo on it yet. Got the starter recoil/rewind all lubed up and ready to put back on the MK55 Thank you all for your input on this subject.

Hooked up the gas line and tank today on the Merc MK55.
Pumped up the gas and squeezed the bulb up nice and hard. No signs of unwanted gas coming from anywhere. Then went ahead and put the recoil top back on. Took her out of the barn and brought her home and set it in a barrel for the initial start up. Prior to that I put a little Marvel Mystery oil in the cylinders.
After about 4 pulls she fired right up. Idling nice. Then another good sign. Water coming out the exhaust hole where it's suppose to. No tell tale on this motor.
Recoil works great all lubed up. Lubed up the controls too.
Now I'm going to wait a few days with gas in it and see if it still runs good. I'm pretty sure the poor running of this motor after a few days with gas in it was because of the old cork floats. Right now,it idles,shifts and pumps water fine.
This motor was on an old Sea Maid fiberglass when I found it in 2003

I thnk your motor may have a telltale. It is a hole on the lower port side of the bottom cowling. It feeds off of the water in the exhaust cover jacket. It is a small hole and easily plugged. Some stiff wire may rectify the issue...

As for the 14" prop - if the motor sounds like it's lugging at all, go back to the 12. The Mark 55s like to rev and if you lug them down, they'll die a premature death.

- Scott

Chinewalker,
I will check for that tell-tale.

Also I will make sure if the motor lugs with the 14" prop on I'll switch back to the 12.

put a tach on and it should be about 5500rpm's at full throttle..

Yep. You are right, that is the best way.
Pumped up the bulb today no leaks, Started right up and run nice.
Will lake test it Thurs.

Lake test postponed until better boating weather. I don't care to go boating when it is 47 and drizzling. Hopefully Fri or Sat.
I did do another barrel test today and it started right up and run fine.
No gas dribbling out anywhere.

Got the Mirror Craft with the MK55 on the lake and running. She runs pretty good with the 14" pitch prop. RPMS up there nice.
Just got to tweek the carbs a little more. Can't do it Solo.
The old girl is doing just fine. Running Quart of oil to 6 gals.

Also got the 62 Homelite up and running this evening on the test stand.
I was nervous about it until I heard her start up and purr. Will put it back on the pontoon the 1st of May.
Had to replace the distributor drive key (cam) and a distributor.
My old distributor come apart and jammed up. Resulting in a broken drive key. Hence cam work. While it was apart I rechecked the valve clearances and made the proper adjustments also a cam spacer. Happy Camper, got alot done.