Mercury Mark 5, first run, first problem

[Buccaneer]

Steve, I too am learning that these Mercs can be frustrating!
Could you have shortened the tang on the neutral spring
to make it work instead of reusing the deformed one?
I messed around with mine half the day. The determination was
that the prop "was" slipping, and that the neutral spring "was not"
releasing! I took the gear case off (but was able to leave the "shoe piece"
and water pump in place!) and put the stub drive shaft in the vice
and was able to slip the prop fairly easy. Ended up making a shim
out of aluminum flashing and put it under the prop nut cone spring.
It would still slip, but with much more effort. While the gear case was
off I played with the shift cable while watching the neutral spring
and the finger that’s suppose to catch said spring…. it was not engaging.
The only way I could get it to do so was remove the plug from the shoe
and push the cable (and catch finger) up further and tighten the cable
up on the top side.

I can now run wide open with no prop slippage and I have neutral (just barely),
but can’t seem to get the shift handle adjusted within the service bulletin
specs.
Perhaps I need a new spring with a longer tang!!! 🙁

It idles beautifully and most times sounds good wide open, but it did load
up a couple of times.
Murphy’s law says all the exhaust must blow the wrong direction, so
perhaps it was lacking proper oxygen to run correctly at times.
I’m thinking my 16:1 fuel mixture might have been a little rich as well.
Oh well, there’s hope for it!

Prepare to be boarded!

[dockbuster1]

Two thoughts if the cable is too taught it will jump in and out of gear tipically when the prop is slipping it is far smoother . Todays lower unit lubricants are far more slippery and could cause a lack of grab of the spring on the drum there is still 90 wt. non synthetic lower unit lube available which has less lubricity

[dave-bernard]

they DON’T use oil they use GREASE.

[20mercman]

quote Buccaneer:

Steve, I too am learning that these Mercs can be frustrating!
Could you have shortened the tang on the neutral spring
to make it work instead of reusing the deformed one?
I messed around with mine half the day. The determination was
that the prop “was” slipping, and that the neutral spring “was not”
releasing! I took the gear case off (but was able to leave the “shoe piece”
and water pump in place!) and put the stub drive shaft in the vice
and was able to slip the prop fairly easy. Ended up making a shim
out of aluminum flashing and put it under the prop nut cone spring.
It would still slip, but with much more effort. While the gear case was
off I played with the shift cable while watching the neutral spring
and the finger that’s suppose to catch said spring…. it was not engaging.
The only way I could get it to do so was remove the plug from the shoe
and push the cable (and catch finger) up further and tighten the cable
up on the top side.

I can now run wide open with no prop slippage and I have neutral (just barely),
but can’t seem to get the shift handle adjusted within the service bulletin
specs.
Perhaps I need a new spring with a longer tang!!! 🙁

It idles beautifully and most times sounds good wide open, but it did load
up a couple of times.
Murphy’s law says all the exhaust must blow the wrong direction, so
perhaps it was lacking proper oxygen to run correctly at times.
I’m thinking my 16:1 fuel mixture might have been a little rich as well.
Oh well, there’s hope for it!

I was very seriously considering filing down the tang on the new spring, but after I was able to restore to original one, (it really came back to original looking condition,) I figured I would give it a try. It worked, so I didn’t need the other one. I had a call from Marineengine.com about another part, and I mentioned the spring. They offered to take it back, so I sent it back to them.

As for 16:1, yes, that is really way too much oil for these. I have found that anything richer than 24:1 is way too much. These don’t need all that oil, and I have found they don’t like it. I run all my regular service Mercs, (not during break-in) at 48:1 unless I have some richer gas mix to use up.

Steve

[billw]

I’m not saying this should be law but I always have run my Mark 5s and 6s on 24:1 and have never had a problem. I also use 90 weight gear oil with no shift problems….but in my case that’s okay because I have nice, tight, resealed cases. As for loading up, make sure there is gas/oil spewing defiantly into the lake, from that little copper tube sticking out rearward, below the power head. Some people assume it will be water discharge but it’s a crank case drain. God Bless 1950s America….but don’t let the clam cops see it.

Long live American manufacturing!

[Buccaneer]

Bill, My copper tube is spewing oil and somewhat disgusting me… and it’s
only dripping in my test barrel so far. Perhaps it needs a diaper retrofit!

Prepare to be boarded!

[billw]

No, that’s perfect! That’s what it is supposed to do! Be disgusting! That’s how you know it works! 😀

Long live American manufacturing!

[Buccaneer]

I realized the disgusting crankcase drain tube was oriented the wrong
way, so it dripped on the transom mount. Turned it around so it
will drip directly in the Land of Sky Blue Water.
Made a new gas line as well today. Old ferrule would not seal.
No sense spewing gas as well!
I too "tried" marine gear oil in my Mark 5, but wasn’t so lucky.
Drip, drip, drip.
Put some old Texaco outboard grease in it today. It was all I could
do to squeeze the tube "hard and long enough" to get it to come
out that tiny vent hole 🙁

Prepare to be boarded!

[billw]

Mark 6s are tough engines to work on, for their size. They usually end up needing a LOT of work, too. They are very needy, because In the span of their lives, they are not likely to run into an owner or mechanic who has the time and patience to really make them right. So congratulations. You just graduated from an advanced course in mechanical patience and should be proud of yourself. They really ARE nice running engines, once you’ve flogged them for enough time.

Long live American manufacturing!

[green-thumbs]

Very few outboards from any era received routine preventative care let alone expensive repairs. The relatively low value of an "old boat motor" very often reflects the fact that it
did not run the last time it was used. In addition to pre existing conditions many old outboards suffer from…fuel left in tank, water in gear case leading to rust or freeze damage, left
out in weather storage and becoming a home for rodents or wasps. Many old outboard also show
signs of unskilled mechanics (not aomci member I am sure.) If it was bought when HST was
playing the White House piano and put in permanent storage when Ike was playing over par
golf expect it to need more than fresh fuel and a pull on starter cord. Refreshing and few are
the exceptions. We who like mechanical challenges love old outboards…even if they do cause us to expand our vocabulary in frustration.
Louis
3/8 pint of Kiekhaefer Quicksilver 2 cycle engine oil per gallon of gasoline
All models use Kiekhaefer Quicksilver Gear Lubricant in lower unit.
.

[Author]

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