Force 125 rebuild has leaking exhaust plate gasket

[altitude 411]

Just rebuilt my 1988 force 125 with Wiesco pistons .030 over sized. All gaskets and seals were replaced. I was following break in procedure and was about 7-8 hrs in when I noticed the exhaust plate gasket was weeping water. The engine seemed to be running OK and would idle and start fine. I had just started to open up to 3/4 throttle and change rpms frequently.
I have torn the engine down to the point that I have removed exhaust head and exhaust plate.

Question: 1) Is it common to have a warped exhaust plate or should it be flat? Mine was warped when I rebuilt the engine and at the time I thought that since it was exposed to heat from the exhaust and also water that it might be common to be warped. Is this the cause of the gaskets not sealing ? Should I have used a sealant on the gaskets?

Here is a video of the leak just before I tore the engine down to investigate. https://www.youtube.com/watch?v=X_AbOv8Gk5o

Do you think I did the engine harm? there is oil on the water side of the exhaust so I believe water was also getting in the combustion chambers. Would you recommend replacing the rings and starting the break-in procedure over? Should I spray WD-40 in the cylinders while I'm waiting for new gaskets and exhaust plate to help displace any water to prevent rusting? I will have this repaired by the weekend.

included some photos of piston/cylinder/rings after leak as well as exhaust plate.

Thanks for any comments and/or advise in this matter

 

[altitude 411]

I think I've miss spoke. I meant to say exhaust port not plate... excuse my mistake

 

[jerryjerry05]

Yes add WD
The warping on the plate is normal.​

If you used a new plate it would warp as soon as you get it running.​

The gaskets need gasket sealer to stop the leaking.​

The surface where the gaskets/plate and the cover go should have been milled and made like new.​

No where in the rebuild directions does it say to do this.​

The heat and use wears the edges off the old surface making the gaskets hard to seal ​

Thus the need for sealer or resurfacing, or sealer.​

You probably did no damage and the rings should be ok.​

 

[altitude 411]

Thanks jerryjerry05 (x2). I did spray gaskets with Hylomar but obviously to no avail. What is recommended sealant for the new gaskets I have on order. Obviously something oil/gas/temp resistant. Do you recommend treating both sides of both gaskets?

 

[jerryjerry05]

I use Johnson/Evinrude sealant.
Yes both sides.
Silicone would be acceptable.

 

[altitude 411]

thank you sir for your time and recommendations

 

[altitude 411]

I am STILL waiting for the correct exhaust port gaskets on my 125 rebuild. I have notice some strange cylinder scoring marks and would like the opinion of the masters here on the forum if possible. Photo #1 shows the cylinder marks and photo #2 shows some ring wear after maybe 7 hrs of break-in procedure.Also, in photo #3 there is some strange what look like almost stress cracks or ?? in the exhaust port cooling side of the block. Is this a casting issue or am I in trouble?

 

[jerryjerry05]

The first looks like a scuff or wear spot.
If it gets worse?

The second: the rings need to float in the groove, tight but still need to move.

The stress cracks??? Without being able to see the other side? They could be
molding defects?

Take to a machine shop and ask them to inspect.
Did you get it bored or honed?

 

[altitude 411]

Yes it was bored and honed from a machine shop. It went from a stock bore to .030 over. The shop that did the machining is reputable but ?? The ring end gap was slightly tight on that cylinder but still withing spec. Do you think that the wear mark looks like a ring butting issue or maybe a out of round cylinder? Do you think it has anything do do with the fact there may have been water getting into the combustion chambers from leaking exhaust plate gasket? This stock motor had eaten rings on cylinder two and four before but I couldn't determine why. Now I see these strange cylinder scuff marks on both of these cylinders after only a few hours of break-in. Do you think it could have a line bore issue? I don't really want to tear the motor all the way back down and start again but what appear to be cracks are very concerning not to mention the wear marks on the cylinder. . I just wanted to ask if you had ever noticed or seen cracks in that location in your travels before. Doesn't sound like it. I don't know about this block. It must have been a weird run of factory builds as the model number is rare as in it's never listed on the parts directory but I did find it in the Force model year chart. I'm bummed I have invested money and time into this rebuild as I could have purchased a remaned power head and been back on the water, Oh well...

 

[jerryjerry05]

The ring gap? why didn't it get fixed before assy?
You remember the gap?

 

[altitude 411]

It was on the tight end of being within Wiseco spec. Not out of spec or it would have been addressed

 

[jerryjerry05]

When the motor gets hot, the rings expand.
I fit the rings to compensate and use the looser fit.