1956 Fleetwin Water intrusion in cylinder?

[RogersJetboat454]

Hello all!
It’s been many years since I’ve posted on Iboats. Good to see some of the old hands are still around after thumbing through a few of the newer posts.

I come here asking for some feedback on an issue I’m having with old friend. A ‘56 Fleetwin I freshened up back in 2012 that I did a four page post on in this thread;

1956 Evinrude Fleetwin freshen-up

Suppose I will add another thread about the humble little Fleetwin. This is my cousin's motor, and in fact the first motor I got to operate solo some 15+ years ago. I have fond memories of taking her out to explore the lake (in our general area of course), as well as my cousins I'm sure...

forums.iboats.com

At the time the motor was owned by my cousin, and has been since given to me.
I’d be surprised if it had more than 3 gallons of fuel run through it since I went through it. Probably the main reason being is it still had lackluster top end performance. Starting/midrange it runs great.

A quick punch list of the stuff done during its cleanup back when:
-LU completely resealed, with lower drive shaft replaced (spring had expanded).
-New water pump
-All powerhead gaskets had been replaced w/ new ones from Vintage Outboard.
-Carb cleaned/rebuilt, NOS low speed needle installed.
-Fresh OE set of points/condensers installed.
-7MM Copper core wires installed
-Set points based on flywheel marks
Already had coils replaced previously, and seemed in good shape.

During the refresh a couple issues were found. The major one was the head gasket for the lower cylinder had blown, and was allowing water ingress. I leveled both the head surface, and deck surface on a piece of glass with 600 grit paper, and the new head gasket had been installed.
Second issue found was some pitting in the upper cylinder, but I was told that the 20:1 oil ratio I run in this would make this a non-issue. If I recall correctly, this was making around 90psi on both cylinders when I was done putting it back together.

So, that brings me back to now. Still has lackluster top end pushing either a 12ft, or 14ft aluminum boat. The neighbors little 5.5hp Ted Williams on the 12ft boat will give it a run for it’s money.
First thought was perhaps I’m loosing spark, but a spark gap tester installed on either cylinder is looking constant, and hot blue.

Took apart the reed valves (which I hadn’t touched in 2012). Was a bit of crust on the aluminum plate, but nothing crazy. Cleaned the valves/plate with scotch brite, and 600 grit. Carb checked to be sure I was getting WOT. Didn’t seem to make much of a difference.

Final check I did, since the lower plug looked a little bit cleaner than the upper, ran it with the lower plug out, and was getting a bit of a mist of water out of the lower cylinder spraying on my hand.

Ah-haaa?

Given that the block/head should be square, with a new gasket installed, and the head bolts torqued to factory specs, I wouldn’t expect it to have a blown head gasket. Also the exhaust plate was taken off, cleaned, inspected during the refresh. No signs of pitting/holes at the time. New gasket was installed with a light coat of 3M 847.

Im at a loss for where the water may be coming from, short of a crack in either the block/head that wasn’t apparent. My
Only other thought is it possibly normal for that cylinder to pull water up through the exhaust ports when there’s no pressure from the combustion process pushing it out?

Sorry for the novel length post, but I thought it’s best to get all the facts right out on the table.

Thanks!

 

[F_R]

First things first: It in NOT normal for water to get into the cylinder under any circumstances. Secondly, water intrusion will slowly but surely destroy the whole powerhead and must be resolved, if it is not too late.

The lower carbon seal has a sneaky way of admitting water into the crankcase, but generally not in the amount you are describing. Even if it is not that bad, any leak at all is not good over the long haul.

 

[oldboat1]

Run at open throttle in the lake, and adjust high speed needle slightly leaner clockwise. See if rpm and speed increase. Adjust the jam nut to hold in place. Readjust the idle screw after h.s. screw has been reset.

20:1 oil ratio seems high, although I don't have my cheat sheets in front of me and memory is getting less and less dependable. Check your manual -- thinking 32:1 might be more appropriate.

 

[RogersJetboat454]

First things first: It in NOT normal for water to get into the cylinder under any circumstances. Secondly, water intrusion will slowly but surely destroy the whole powerhead and must be resolved, if it is not too late.

The lower carbon seal has a sneaky way of admitting water into the crankcase, but generally not in the amount you are describing. Even if it is not that bad, any leak at all is not good over the long haul.
View attachment 347573

F_R, thanks for the reply! I was hoping you were still on here after all these years.
I don't think that I replaced the carbon seal when I did the clean up on this back in '12, so it's something I should order and replace.
What's coming out of that cylinder isn't like its getting sprayed out of a pump sprayer. It's a very slight spitting of water that takes a second to build up on your hand. You may be on to something if that carbon seal is only capable of allowing a small amount of water past.

Something I've been considering doing for a bit of additional troubleshooting was seeing if I could put a set of flush muffs on it (hose on a trickle) with the engine off, and stick a borescope down the cylinder to see if I can detect any water intrusion. Any thoughts on that?

 

[RogersJetboat454]

Run at open throttle in the lake, and adjust high speed needle slightly leaner clockwise. See if rpm and speed increase. Adjust the jam nut to hold in place. Readjust the idle screw after h.s. screw has been reset.

20:1 oil ratio seems high, although I don't have my cheat sheets in front of me and memory is getting less and less dependable. Check your manual -- thinking 32:1 might be more appropriate.

Thanks for the reply.
Carb adjustments have been tuned for peak performance on both low speed, and high speed needles, and I always do add just a slight favoring of running it a bit rich.

This is a bronze bearing engine (no roller bearings on either the crank bearings, or rods). The original recommended oil ratio was 16:1. The 20:1 ratio was something that was recommended by members here, when using a modern TC-W3 oil.

 

[oldboat1]

Thanks for the correction on oil ratios. I run '57s, and recall (after your reminder!) that 16:1 is called for with the 7 1/2 -- unlike the others in the line. I haven't run mine in a couple of years, but go with the book ratios.

 

[oldboat1]

on the water intrusion -- Maybe the head is badly warped. Could try resurfacing it until mating surface has an equal shine all around (w/d sandpaper on a hard surface). new gasket and retorque.

 

[RogersJetboat454]

on the water intrusion -- Maybe the head is badly warped. Could try resurfacing it until mating surface has an equal shine all around (w/d sandpaper on a hard surface). new gasket and retorque.

Thanks for the reply.
Both the head, and the deck of the block was resurfaced back in 2012 with sandpaper taped to a piece of tempered glass.

I had taken lots of photos of the process which are in the thread I linked in my original post here to show how I do it, incase someone else wanted to do the same.

Sealing surface sprayed with paint, allowed to dry, then start sanding. Remaining paint after sanding sessions show the low spots to continue working to till all the paint is gone.

 

[RogersJetboat454]

 

[RogersJetboat454]

Just wanted to update this posting, mostly for a reference to someone who might have a similar issue down the road. .

After taking 2 months to get my butt in gear, per F_R's suggestion, I finally pulled the powerhead last night to check the carbon seal.

What I ended up finding was the carbon seal is chipped, and wallowed out. When compared to a new carbon seal, this one probably has a few 32nd's more space between it and the drive shaft.
The drive shaft itself has some pretty deep scoring. I ended up ordering a new one from Marine Engine since they're still available, and I didn't want to have to worry about condition issues with the used junk off eBay.