1988 Evinrude 150HP cylinder shot? *pics*

[Power_Dr]

I have a 1988 Four Winns with a 150HP and I noticed that I lost power. I took out the top right spark plug and it was full of metal. The metal fused the tip of the plug to the ground bar. We took the head off and this is what I found. Did this overheat?

The other 2 cylinders look like this

Where do I go from here?
I had the power head replaced a few years ago, I am not sure if the water pump was replaced. I have always seen that the motor "pees" just fine. Can I just replace this piston and hone the cylinder walls? or am I screwed?

 

[Monte1961]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

Better check the head while your at it!

 

[bernd64]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

i call this we need a new piston. looks like for me you a runing to lean on oil.

 

[Power_Dr]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

The head gasket looked ok. It is oil injected, and I don't know where/how the oil gets into the cylinders. Are there oil injectors for each cylinder? or does it mix with the gas by the carbs?

I am guessing that I got water in from the head gasket.

 

[cfauvel]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

The head gasket looked ok. It is oil injected, and I don't know where/how the oil gets into the cylinders. Are there oil injectors for each cylinder? or does it mix with the gas by the carbs?

I am guessing that I got water in from the head gasket.

The oil is "injected " into the fuel at the fuel pump.

I doubt that is a low oil issue since the other cylinders look good and there is obvious evidence of water in the bore (rust).

My guess and hope for you is that it was a blown head gasket, otherwise it could be a cracked block.

What a shame...this is going to cost a bundle.

 

[emdsapmgr]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

Pull the carb apart that feeds that bad cyl. Esp, check all the jets on the side of the carb for that cyl. You may find some debris in the the main jet. If so, that can starve that cyl for lubricating fuel/oil. Further, check the rubber water diverter for that cyl. If it is out of position, that one cyl can run hot, yet not set off an overheat horn. That cyl shows a lot of rust, unlike the other cyls. Possible you have a water leak in that cyl. Check the head gasket seal ring for that cyl.

 

[Power_Dr]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

I will check out the carbs.

What would happen if I just run it like this, and maybe not connect that spark plug wire on that cylinder. Then just run on 5 cylinders, so I can use the boat a little this summer. Is the damage already done, and can't get any worse? What would the oil/fuel do that just blows out that cylinder? how much more damage would I do running it like this?

Thanks for the replies.

 

[cfauvel]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

While I'm no expert outboard rebuilder or mechanic for that matter. Take my advice with a grain of salt or two.

You shouldn't run the motor with that rust in there. I am very surpised the bore looks this bad, figuring that if the piston rings were still good they would have shined up the bore nicely after a few revolutions.

Aslo if there is rust in the bore, where else is there rust? bottom of block? all up in the roller bearings? Scary.

I also would be afraid of the piston, now distorted, that it would kiss the cylinder head.

Try to get rid of the rust.

with the heads off, rotate the flywheel a couple of times by hand, (all spark plugs out), and see if the bore cleans up a bit, if so then you may still have rings that are still inplace, good rings? uhm probably not, but...

Then rotate the flywheel to bring that piston to just below TDC.

Place some modling clay in the head's crown and reattach the head without gasket, rotate the flywheel in the same direction gently and see if the top of the piston is kissing the head.

With that corrosion on the piston, your compression ratio on that cylinder would be slightly higher, and thus slightly hotter than the rest.


If so and you are guttsy, grind down the top of that piston, to reshapen it like the others.

And after that and feeling gutsy, bolt everything backup, with gasket, verify the carbs are delivering fuel and try running the motor again....then after several minutes of running, stop the motor and let it sit for overnight. The following day remove the head once again and see if rust is forming again. If so and you are absolutely sure you replaced the heads correctly I'd say you have a crack somewhere letting in water.

I feel so sorry for you buddy.

 

[emdsapmgr]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

That rust is indicative of some other major problem. You either have a bad head gasket or you have a water leak at the exhaust manifolds. Usually exhaust manifold water leaks affect the bottom cyl, not the top. If you continue to run this with this water ingestion problem, you could get enough water in the cyl to get a hyraulic lock. Then other bad things happen.

 

[cfauvel]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

Power_DR, what have you dcided to do?

 

[Power_Dr]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

Thanks for all the replies.

We haven't done anything with it yet. We have contacted the local tech. college and then say they can take projects like these and fix them for the cost of parts.

My brother wants to take it out and run it as is and see if the cylinder cleans up. I know the piston needs to be replaced, but since it is so nice out he wants to use the boat. I don't know that it can get any worse than it is right now?? I don't know what would happen if he took it out and just didn't connect the plug wire to that cylinder. I don't know anything about 2 cycles, just cars, but if you don't connect the plug wire the fuel would just blow out the exhaust unburnt, what would that do to the rest of the engine?

 

[emdsapmgr]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

If you run the engine the way it is, you are asking for a failure at an unopportune time. I would prefer not to have to be towed home with my family in the boat, once the engine quits miles from the boat ramp.

 

[cfauvel]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

Thanks for all the replies.

We haven't done anything with it yet. We have contacted the local tech. college and then say they can take projects like these and fix them for the cost of parts.

My brother wants to take it out and run it as is and see if the cylinder cleans up. I know the piston needs to be replaced, but since it is so nice out he wants to use the boat. I don't know that it can get any worse than it is right now?? I don't know what would happen if he took it out and just didn't connect the plug wire to that cylinder. I don't know anything about 2 cycles, just cars, but if you don't connect the plug wire the fuel would just blow out the exhaust unburnt, what would that do to the rest of the engine?

It is not good for the regulator/rectifier to have voltage go no where, I don't recommend running the engine the way it is, but if you were to run the engine withou that cylinder, I would remove the spark plug from the head , leave the spark plug connected to the wire, wrap wire all around the threads and have that wire connected to a ground.

This way that cylinder is NOT getting compression, and the plug is grounded not destroying the regulator.

However, water could get into the cylinder and make a mess with un burnt fuel.

Seriously don't succumb to his wishes, get the engine fixed or do what I suggested before , first turning the motor by hand with no plugs in, to see if the walls clean up. Grind or scrape off that stuff on the piston head, verify that the piston is not kissing the head....all that stuff mentioned before.

If you do let the brother talk you into running the engine, will he help in the repair costs and towing in?

 

[wilde1j]

Re: 1988 Evinrude 150HP cylinder shot? *pics*

Motor is close to becomming a paperweight. The bad hole looks like it needs to be resleeved (not a job for a local technical college, nor is boring the other holes). Keep running it and you can just throw it away when it craps out.