1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

[TOP1PERFORMER]

Hey guys any thoughts?

I have a low hours and very clean 1987 88 SPL. Engine runs great looks great. Water coming out from the top front midsection near the top pivot. Removed the cowl but can't see up there close enough where it's running from.
Last week I pulled everything apart to try to find the leak. Did not see any corrosion. New water pump, seals, o-rings, gaskets, super cleaned all surfaces at powerhead and exhaust adapter. The leak is still there. Called Evinrude direct and they thought that maybe the mating surfaces between the powerhead and adapter may be warped. Suggested trying another new gasket with Permatex #2. I did use a very light coat of silicone sealant on both sides of the Powerhead/Adapter gasket which may not be preferred. Exiting water looks very clean and not contaminated with oily exhaust. If no ideas then I might need to install the powerhead without the lower engine cover/shroud for an open view and then disassemble and reinstall again. Ouch..

 

[Bosunsmate]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

It might be a leak in your intake pipe near the top.
Not sure how it would warp near the pivot as thats well away from any heat.

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

It might be a leak in your intake pipe near the top.
Not sure how it would warp near the pivot as thats well away from any heat.

Could you clarify intake pipe? Not sure what you are referring to. Do you mean the top of the water tube from the water pump? Thanks

 

[Bosunsmate]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Yep, maybe it has a corrosion hole on the water intake pipe or your upper grommets gone and the water is pressuring out a vent hole up there somewhere.
Whenever i do a powerhead exchange i always fill the intake pipe from the top to check its holding water( thats with gearbox off and the bottom of pipe plumbed.
I suppose you can run a straight edge to check those mating surfaces arent warped. Itd have to be pretty warped to not be stopped by the gasket there if it was warped .

 

[emdsapmgr]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

You have not mentioned specifically that you removed the powerhead and replaced the base gasket. Those do tend to fail on the V4 crossflows when they get older. Most tend to leak exhaust gas into the cowling, but a water leak is also part of their failure mode. If you have not removed the powerhead to replace that gasket yet, you should.

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Hi,

Water tube was removed and new gromet installed with sealant.
Base gasket was also replaced.

Just removed the lower unit and powerhead again. I'm getting pretty quick at it...unfortunately.
Rechecked all seals and gaskets. Everything was solid and sealed well. The base gasket was sealed well and destructed on removal. It actually held on quite well when hoisting the powerhead off. Had to pry it a bit to release it.
When I look at the adapter plate I see the inlet port from the pump tube and next to it which looks like a larger return port to the mid section chamber.
Before powerhead removal I ran a hose to the water pump tube and slowly pushed low pressure water up until it started running out of the open mid section. With a flashlight I could see water running down the overflow port along side the water tube inside at the top of the mid section.
I can find anything wrong.
If the thermostat assembly is hanging up a bit would that redirect water differently? Engine is not overheating. I put the assembly in hot water and 1st thermostat opened at 130 deg F. The second opened at about 145 deg F.
Somehow I think I'm getting water from the top and back down into the mid section. If it's pressurized it could fill up the chamber and spill over the top.
Again, the water exiting is clean and untouched by exhaust.

 

[Bosunsmate]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Did you check your mating surfaces with a level?
I dont think a stuck thermostat would cause your problem.
You could check your drain holes on the leg are clear and also check the exhaust chamber down into the mid section for holes

 

[emdsapmgr]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

You've got an interesting problem. Some good, thoughtful investigation thus far on your part regarding the exhaust adapter. Have you done any water testing with the block? If you remove the water passage cover on the top of the block (where the lifting eye is) and pour water down there, do you see any unusual leakage elsewhere in the block? The thermostats should open at 143 degrees. A stuck stat will prevent water flow through one side of the block, until the water pressure increases to the point at which the pressure relief valve(s) in the thermostat housing opens. (That's usually when the boat gets on plane. Or, the pressure relief valves may open when revved from idle.)

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

You've got an interesting problem. Some good, thoughtful investigation thus far on your part regarding the exhaust adapter. Have you done any water testing with the block? If you remove the water passage cover on the top of the block (where the lifting eye is) and pour water down there, do you see any unusual leakage elsewhere in the block? The thermostats should open at 143 degrees. A stuck stat will prevent water flow through one side of the block, until the water pressure increases to the point at which the pressure relief valve(s) in the thermostat housing opens. (That's usually when the boat gets on plane. Or, the pressure relief valves may open when revved from idle.)

Hi,
I had the inner exhaust chamber out when I removed the water tube and replaced the grommet. Everything was cleaned very well and no corrosion or cracks.
I have not tested the block but I've visually inspected for cracks, etc. and nothing. I like the idea of running water through the upper passage. Will try that tonight after work.

Just a note: I only see the water leaking at fast idle and at running speed. Slow idle looks OK. I assume it's happening when the pump is reving up cranking up a little pressure.

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Also, mating surfaces were not checked with a level but gasket had good contact with destruct on removal. Will check regardless.

 

[emdsapmgr]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

When the engine idles, all cooling water goes through the thermostats. Once you rev the engine (or get it on plane) the extra force of water flow will cause the pressure relief valves to open. This will flood the power head with extra cooling water. This may correlate to your observation about just when the water starts to leak. Also, you may see more water flow out of the exhaust relief holes once the pressure relief valves open. Did you use gasket sealer on the powerhead base gasket?

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

When the engine idles, all cooling water goes through the thermostats. Once you rev the engine (or get it on plane) the extra force of water flow will cause the pressure relief valves to open. This will flood the power head with extra cooling water. This may correlate to your observation about just when the water starts to leak. Also, you may see more water flow out of the exhaust relief holes once the pressure relief valves open. Did you use gasket sealer on the powerhead base gasket?

Got home from work late tonight and just back in from looking over the engine again. It's 1am...

Yes, I used gasket sealer on both sides. Removed all gasket and sealer material tonight. Inspected for warpage. Slightly off but don't think its not enough to release that much water. The minute high spot I see would actually seal the ares caontaining water even better. Could be wrong though when under pressure. I also rested the porwerhead on the adapter without a gasket and then with a new gasket. Checked around with a feeler gauge and again nothing stood out.Considering 2 gaskets to allow for more compression on any high spots but concerned that they may let go. Don't really think there is enough pressure to blow them. Not sure if that would be enough to affect the o-ring seal at the splines on the driveshaft.
Pressure tested block for cracks or leaks and everything is tight.
It it's not the gasket the only other thing I can think of is maybe water is finding it's way up the driveshaft tube and running out the top. That is the area water running out. Water Pump has new grommets at the water tube and driveshaft locaton. Flat side down at driveshaft. Will check tomorrow for imperfections in the casing to ensure a good seal.
Is there anything in the pump housing that would let water run up between the grommet and shaft? From all the info I have there should be an o-ring on the bottom of the impellar above the plate, I think an o-ring between the water pump housing and stainless cup and the preformd o-ring that runs the perimeter of the housing that seals to the plate. I'm wondering if either of the 2 smaller o-rings were missing, misinstalled or defective, would water run up.

I'm fried and going to crash. Catch you tomorrow.

Thanks to all for your input so far.

 

[Bosunsmate]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Ive almost seized a 2.4 diesel turbo on a pickup by running two gaskets on an oil filter by mistake so i wouldnt suggest doing two gaskets unless its being tried before by many others successfully.
I suppose you have checked the grommet for the water tube in the water pump base? i replace those every couple of times i do the impeller

 

[emdsapmgr]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

A couple of reference questions. When you run your engine, do you get water flow out of the two relief ports at the top of the midsection. If you run it on the trailer, do you get water flow out of the two vents at the top, rear of the midsection-right above the prop?

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

A couple of reference questions. When you run your engine, do you get water flow out of the two relief ports at the top of the midsection. If you run it on the trailer, do you get water flow out of the two vents at the top, rear of the midsection-right above the prop?

All grommets new. Checked and rechecked.
Oil pressure is typically higher pressure than water pressure. May be completely different when considering 2 gaskets.

Water does flow as normal out of the 2 round relief ports at top back of mid section.

Before disassembly I ran the engine in a short barrel with water intake and prop submerged just below where bottom unit and mid section come together. Wanted to mainain similar back pressure as if boat was in water. I was getting water out the side vents above prop, lower mid section rubber mounts, the small 1/8" x 1/8" cutout in front where lower unit, mid section join and with high idle up at top front by the rubber thrust mount. Lots of water. Never tested the engine this way so not sure if it's all correct.

 

[classiccat]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

...
Before disassembly I ran the engine in a short barrel with water intake and prop submerged just below where bottom unit and mid section come together. Wanted to mainain similar back pressure as if boat was in water. I was getting water out the side vents above prop, lower mid section rubber mounts, the small 1/8" x 1/8" cutout in front where lower unit, mid section join and with high idle up at top front by the rubber thrust mount. Lots of water. Never tested the engine this way so not sure if it's all correct.

In a tank, it's recommended that you completely submerge the water pump...at a minimum upto the lower motor mounts.

I've always assumed this is necessary since the engine is stationary and water isn't being forced into the intake as it would be when you're underway.

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

In a tank, it's recommended that you completely submerge the water pump...at a minimum upto the lower motor mounts.

I've always assumed this is necessary since the engine is stationary and water isn't being forced into the intake as it would be when you're underway.

10-4. That's how I started the process. Boat was floating. Took it home and had it in a 55 gal drum. Final test ran it at the last level indicated. Pump had no problem drawing it in. Pumped like crazy.

Here is the latest and if this is the problem I might just hang myself:
Pulled the water pump. Separated the cup from the water pump housing. No o-ring in between. That could allow water to bypass the the assembly and send it up the driveshaft channel to overflow up top. I'm assuming when I bought the water pump kit the cup was already installed and I might not have checked. Could have been another late night install. How stupid is that.
Hopefully that's it because I'm out of ideas. At least I know now that every seal, grommet and o-ring is new. Engine is spotless inside and out. Also, know alot more about this outboard and can pull it apart in 1 hr.
Will conclude after reassembly.

Thanks

 

[emdsapmgr]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Agree with you. Seems most likely that the water is coming up and out of the driveshaft hole, which is in the front of the adapter. The rest is sealed once the powerhead is secured in place. When you had the water tube out, did you pressure test it? Inspect for leaks, fractures in the tube? How does it seat in the bottom of the adapter?

 

[TOP1PERFORMER]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Agree with you. Seems most likely that the water is coming up and out of the driveshaft hole, which is in the front of the adapter. The rest is sealed once the powerhead is secured in place. When you had the water tube out, did you pressure test it? Inspect for leaks, fractures in the tube? How does it seat in the bottom of the adapter?

Water tube was removed, cleaned to bare copper. No visual cracks. Pressure tested with air. All good. It seated flush in the adapter with a new grommet. Sealant on the outside of the grommet when pressed in as described in the service manual.Had the same water leak with the old grommet and new.

 

[Bosunsmate]

Re: 1987 Evinrude 88 SPL Water Leak between Mid-section and Powerhead

Since you can disassemble so quick i can only suggest reassembling without lower cowling on to pinpoint its location