Head Gasket or New powerhead or ????

[modernrocketry]

I need some advice and direction on what to do next?
This is a 1996 Johnson Evinrude 115 TurboJet ? Effectively a 115 mounted to a Jet drive.

Some Background information: A couple weeks ago, the engine overheated due to a crack in the raw water strainer.

Over the weekend, my Johnson Evinrude 115 would not start. The starter would engage the flywheel, but could not turn it. The battery voltage was good and the battery is less than 1 year old. Regardless, I got a new battery and cleaned the cables, both on the battery and engine. Didn?t solve the problem.

On a whim, I removed all 4 spark plugs, and tried to start the engine ? the starter engaged and spun the engine without problem. However, one of the cylinders spit out quite a bit of water mixed with fuel. I?m not certain of the cylinder number, but if you looking at the powerhead, with the cylinders facing you, it is the one on the bottom right.

I put the plugs back in and the boat started fine. I ran it for about another 2 hours. I noticed at low RPMs it seems like this cylinder is not firing (I?m guessing) but after running at 2800 rpm for a few seconds, the RPM will Jump to 3300 and the engine sounds nice and normal.

Also, I use the VRO pump (I have revision 9) and use Johnson Evinrude XD50 oil only. I have noticed what appears to be more white smoke at idle and low speeds this last year. ? could this be related. Perhaps a weak head gasket allowing a bit of water into the chamber and steaming it out?

So my question is ? did I kill my powerhead? How can I check? Compression test? What is the best tool to buy to check compression?

Or -- since I have to pull the powerhead from this boat to conduct the repairs and this engine is almost 15 years old -- should I get a new powerhead?

Please advise.

Thanks,
Miles

 

[ezeke]

Re: Head Gasket or New powerhead or ????

You probably blew a head gasket, but now you may have a bigger problem of rust.

The extra smoke may be steam. It is possible but difficult to replace the head gasket without pulling the engine. Use sealer on a new gasket.

If the VRO (It's actually an OMS, not a VRO) has an air leak on the gasoline side, the pump will over-compensate and pump too much oil; that will definitely get you plenty of extra smoke.

Once you have a good seal on the cylinder bank, a compression test should let know where you stand.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Ezeke,

thanks for the Reply. I'll order a head gasket and replace it.
What type of sealer do you recommend?
and is there a compression testing tool that is recommended? I'll be buying it and don't mind spending a little extra for quality.

 

[ezeke]

Re: Head Gasket or New powerhead or ????

These are good: http://www.thetoolwarehouse.net/p-3790-mityvac-mv5530.aspx

Gasket sealer: Check with your auto supply for what's good. I use mostly 3M 847.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

I ordered the tool. Thank you for the recommendation.


Can you expand upon the Rust problem -- how likely is it? I run exclusively in Salt Water. How would the problems manifest themselves?

 

[ezeke]

Re: Head Gasket or New powerhead or ????

When the head gaskets break, the cooling water often reaches the cylinder which is steel. If the water gets to the piston, the rings can rust and stick. If the rings rust to the cylinder they can bind the engine. If the water gets behind the piston it can damage the bearings and the crankshaft.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Thanks for the input Ezeke.

I went to my big boat and grabbed the service manual for my TurboJet

I have decided to pull the powerhead to do the service because I believe that after 15 years of use, some of the bolts will likely require some heat for removal and I don?t like the idea of using a torch in a fiberglass boat with tight spacing. From what the service manual indicated ? the removal of the powerhead looks to be fairly simple.

Also, since I am removing the engine I am going to replace the thermostats while I am in there.

I?ll post photos of the cylinders and pistons once I am inside to get some feedback.
So here is what I see that I need thus far:
Please correct me if I am wrong
1. OMC Universal Puller P/N 321537 (to remove engine)
2. Cylinder Head Gaskets (2) P/N 318358 iboats Part # 18-2956
3. Cover Gasket (2) P/N 318335 iboats Part # 18-2873
4. Water passage deflector (4) P/N 322411 iboats Part # 18-0892
5. Cylinder Head Screw (20) P/N 307267 iboats Part # none
6. 3M 847
For the Thermostat:
1. Thermostat ASSY P/N (2) 484841 iboats Part # 9-43101
2. Value body Gasket (2) P/N 332369 (2) iboats part # 18-0977
3. Relief value grommet (2) P/N 321692 iboats part # 18-2391
4. Pressure Relief value (2) P/N 318395 iboats part # 18-3564
5. Relief value spring (2) P/N 317245 iboats part # 18-1243
Questions:
While I have the engine out ? is there anything else I should consider doing?
When I put the cylinder head bolts back in ? should I use some type of antiseize?
The Cover gasket on Iboats says starboard (Although the come 2-to-a-pack ? is there a port or are they the same?
Is there any other advice you can give me? I?ve never done this before, but I am no stranger to tools.

Thanks,
Miles (Obviously OCD by the detailed email above!)

 

[ezeke]

Re: Head Gasket or New powerhead or ????

Puller 0307636 combined with eye 321537 makes a good lifting eye and flywheel puller - you will need 3 screws to pull the flywheel or to lift the engine.

The water covers on the cylinder heads don't need to come off unless you want to clean - the gaskets are the same for both sides. Get some extra screws, they break easily.

Get the Sierra thermostat service kit #18-3673 - it has everything normally needed. You might want extra gaskets.

Get new plate to adaptor gasket if you are going to separate the powerhead to work on the thermostats. Don't take the muffler off the adaptor.

Get some 3M 847 sealer.

If you have time, it's a good opportunity to rebuild the carburetors.

If you don't have a service manual, this would be a good time to purchase one. There are usually some on Ebay.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Ezeke,

Thanks for the reply.

A couple more questions for my parts list:

I'm not certain I am ordering the correct part for the "plate to adapter" gasket.
I am ordering Sierra Gasket 18-2864 Is this correct
In the TurboJet parts catalog on page 12 titled "Adapter & Muffler" which gasket do I need? #7 or #16 or both? and is one of these Sierra 18-2864?

I cannot find the the puller and eye mentioned below -- are they available on iboats?

The screws that have a tendency to break are shown in the Parts Catalog on page 10, titled "Cylinder & Crankcase" #33 and their P/N is 307267. I cannot find these screws -- are they typical hardware store items?

I am ordering 2 carburetor kits number 18-7046. Is there anything else I will need to rebuild the carbs?

Thanks again

 

[ezeke]

Re: Head Gasket or New powerhead or ????

iboats does not sell BRP brand, just aftermarket. Specialty parts are either available through your local BRP/Evinrude dealership,or online BRP authorized stores like ishopmarine.com, boats.net, marineengine.com, maxrules.com, sea-way.com and others.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

I did a compression test on the engine today -- I wanted to know what it was before changing the head gasket.
I'm a little surprised by the results:
Cylinder #1 - 123
Cylinder #2 - 130
Cylinder #3 - 135
Cylinder #4 - 125

Cylinder #3 is definately wet. I found water in the cylinder after I warmed it up.

Does this make sense? could I have compression numbers like the above and still be leaking water into the cylinder? Could it be anything other than a head gasket?

Also, Thanks Ezeke for the compression testing gauge recommendation -- it worked great and was very easy to use. I used the compression testing instructions posted in the FAQ section of the forum: http://forums.iboats.com/showthread.php?t=391323

 

[ezeke]

Re: Head Gasket or New powerhead or ????

In addition to cylinder head gaskets, you can have water from water in the fuel or fuel components, from too much water pressure on a water hose, from a leaking exhaust gasket or from a cracked cylinder. And yes, you can have good compression and still have leaks but it should be better without the leaks.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Okay -- I did it! I actually removed the cylinder heads -- I know this is a no big deal for most of you -- but I had some serious concerns...

I was suprised at how easy it was -- For the TurboJet in a Novurania, you don't need to remove the engine to pull the heads. A few of the bolts were difficult to get at, but not impossible.
THANK YOU EZEKE!!!!!

I didn't break any head bolts -- my technique: I set my torque wrench to 20 lbs/ft and tightened each bolt, then removed each. My experience has been a little tightening make removal easier.

Anyway -- Following are the photos of what I found.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Here is cylinder 1 and 3 with bolts removed, but seal not broken. You can see the head gasket is in poor shape.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Here is Cylinder 1 and 3 opened up.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Here is the head for Cylinder 1 and 3 -- There really is no gasket remaining on this motor. I am amazed I got the compression numbers I got.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Here is Cylinder 2 and 4 holes.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Here is Cylinder 2 and 4 head

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

And Lastly, here's a shot of Cylinder 3 -- the one that has been getting wet.

 

[modernrocketry]

Re: Head Gasket or New powerhead or ????

Obviously Cylinder 3 has some rust in it. I can feel it when I run my fingers around the cylinder wall. Doesn't see too bad, but definately a texture difference.

I know from what was said earlier that rust is like a Cancer -- What are my treatment options?