72 Johnson 65hp -- Water in #2 Cyl --

[Ron Wellman]

Ideas please.

72 Johnson 65hp -- Water in #2 Cyl --

Have very carefully replaced head and all 3 exhaust chamber gaskets in an attempt to determine source of water fouling in # 2 (middle) cylinder. Local helpful (sincerely they are helpful) dealer has said that only other possibility is a crack somewhere in the block. Engine has never been overheated or frozen.

Always starts and runs on all 3 cyl but after warming a bit # 2 fails to fire. Ignition system is not the problem, have confirmed with timing light always fireing. After water fouls the #2 the spark is energetic enough that I see arcing
from the spark plug boot down all the way down the plug porcelain to the metal plug body, lots of arcing (fireworks).

Driving me CRAZY !

Ideas please.

 

[Ron Wellman]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

Just a test relpy post from originator -- Ron Wellman

 

[kenmyfam]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

Do a compression test on all cylinders. How is the spark plug condition of all 3.
How flat was the head before you replaced the gasket ?? did you check ?? could be warped.
Welcome to iboats.

 

[Ron Wellman]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

kenmyfam, Thanks for your interest, glad to have found iboats.

When I pulled the head the existing head gasket was in good condition without any evidence of leaks anywhere. Was disappointed as I hoped for blown head gasket to explain my problems. Of course I installed a new head gasket (no sealer used on head gasket) and carefully torqued bolts in proper sequence. Ditto for the exhaust gas heat exchanger assembly using Evinrude Johnson gasket sealing compound (P/N 508235).

Also replaced all 3 spark plugs when head was reinstalled.

Will check the compression as per your suggestion -- thanks.

When I removed the spark plugs after running the engine # 2 clearly has evidence of water on it. When I replaced the head gasket I carefully inspected everything I could see from the top end, All 3 cyl walls were clean with no signs of damage or scoring. # 2 cyl hole around theports and in the head per se did have oil/water froth consistent with water seen on # 2 plug. Water is there --just don't know from where.

 

[F_R]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

kenmyfam, Thanks for your interest, glad to have found iboats.

When I pulled the head the existing head gasket was in good condition without any evidence of leaks anywhere. Was disappointed as I hoped for blown head gasket to explain my problems. Of course I installed a new head gasket (no sealer used on head gasket) and carefully torqued bolts in proper sequence. Ditto for the exhaust gas heat exchanger assembly using Evinrude Johnson gasket sealing compound (P/N 508235).

Also replaced all 3 spark plugs when head was reinstalled.

Will check the compression as per your suggestion -- thanks.

When I removed the spark plugs after running the engine # 2 clearly has evidence of water on it. When I replaced the head gasket I carefully inspected everything I could see from the top end, All 3 cyl walls were clean with no signs of damage or scoring. # 2 cyl hole around theports and in the head per se did have oil/water froth consistent with water seen on # 2 plug. Water is there --just don't know from where.

I'm surprised your dealer doesn't know this. That motor is notorious for water ingestion. It comes from the exhaust cover gaskets. Not so much the gasket as the plates. There is a long, thin unsupported area of the plate beside the exhaust ports. Even the slightest hint of overheating---or no overheating--- will warp the plate and the gasket won't seal. Take the covers back off and lay a straight edge on the inner plate and you will see what I mean.

 

[Ron Wellman]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

to F_R:

=======================================================
Thanks re: "That motor is notorious for water ingestion. It comes from the exhaust cover gaskets ..........."
=======================================================

I will again remove the exhaust plates and check for flatness with a straight edge as suggested. Given that this is the problem this would be great news rather than other more expensive issues.

If they are warped can they be salvaged by a machine shop grinding them flat of is it simply more cost effective and a more sure fix to simply buy new ones ?

I'll post my findings so all can share.

Ron

 

[Ron Wellman]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

Sept 1, 2009-- Removed exhaust heat exchanger, the thiner plate closest to the block on the side that contacts the block was warped as was suggested by FR in his (her ?) reply .

I carefully lapped the joining surfaces using abrasive paper taped to a sheet of window glass.

Have succeeded in getting surfaces much improved as judged by bright shiny aluminum all across the mating surfaces.

Not 100 % perfect but hugely better. Am awaiting n new gaskets to arrive for reassembly and the real test of "no more water ingestion" in any cylinder.

Again , thanks FR for the input.

Ron

PS

The local dealer did say when I asked that "we always cleanup up the surfaces with sandpaper on a flat surface before we reassemble them". (re exhaust gas heat exchangers) I had failed to ask the right question earlier and it never occurred to the dealer that I would not check for and fix lack of flatness if found.

 

[Ron Wellman]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

Problem Solved !

Had the exhaust heat exchanger plate surfaces planed down at local automotive/marine machine shop.

A 3 cylinders not missing a beat. 1972 Johnson 65 hp good for another 37 years ?

Thanks to all to replied with their ideas.

 

[jay_merrill]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

Good thread. I have the same motor - no sign of water ingestion in mine, but if I ever see it, I'll know where to start!



???

 

[johnnyo34]

Re: 72 Johnson 65hp -- Water in #2 Cyl --

Ditto here, hope it don't happen, but if it does , I'll go straight to the problem.