1990 Force 120HP #2 Cyl zero compression and upon opening piston shows damage

[Nordin]

If this engine was mine I should do just one hole.
I have bore many engines and I have done only the cylinders that needed.
Question to go for 010 or 020 is up to you.
If you are sure your measurements are true and correct and 010 will be enough, well go for it.
If 010 not clean the cylinder walls you have to do another 010 and buy a new piston.
The engine will last for a very long time if you maintain it well and not run the hell out of it, soo a new rebulid is not likely in the near feature.

 

[topgun3690]

The engine will last for a very long time if you maintain it well and not run the hell out of it.

You gave me the same advice when I replaced my PH.....and that is exactly what I do......

 

[gica]

If this engine was mine I should do just one hole.
I have bore many engines and I have done only the cylinders that needed.
Question to go for 010 or 020 is up to you.
If you are sure your measurements are true and correct and 010 will be enough, well go for it.
If 010 not clean the cylinder walls you have to do another 010 and buy a new piston.
The engine will last for a very long time if you maintain it well and not run the hell out of it, soo a new rebulid is not likely in the near feature.

I have to get a new piston anyways. If I get 4 it will go up in price. I was gonna get on bore at .010 and the rest just new rings. I measured it 100 times. With the telescopic gauge I got the 3.3782. That's the largest I got the dial gauge was a bit less. It's all up there in the picture of the page I wrote.

 

[gica]

So I decided to buy 4 new pistons and rings .020 spending 700 bucks to repair this is not a lot.
I have a question in the books they mention a sealant as industrial 750 sealant. I don't know if that is available but what have you guys used to seal the crank cases together and the bottom end?
Does permatex have something? Or other brands? I mean if it works on cars it has to also work on boat engines.

 

[racerone]

Johnson / Evinrude " gel seal "----or----Loctite 518 ----Use nothing else.

 

[gica]

Johnson / Evinrude " gel seal "----or----Loctite 518 ----Use nothing else.

I noticed the 2 halves have a groove, this is similar to BMW crank halves there you inject the sealant until it comes out.
So I assume the sealant is only put in the groove space right not on the whole edge.
Is this the Johnson

Johnson - Evinrude 0363975 Gasket Sealing Comp 16OZ w/Brush

Johnson - Evinrude 0363975 Gasket Sealing Comp 160Z w/Brush is now available at Wholesale Marine. Shop today for low prices on OEM Johnson/Evinrude parts.

www.wholesalemarine.com

Or this

Evinrude/Johnson Loctite Gasket Sealant No .2 (910032)

An engine assembling compound or pipe fitting cement. Dries to a soft, pliable film Non-hardening Seals cut gaskets and stamped parts Resists gasoline, oil, steam, water, grease, mild acids and alkalis 3oz Tube

www.bargainboater.com

This is the Loctite 518
Loctite 518 Gasket Maker Flange Sealant https://a.co/d/irBH2rq

 

[Nordin]

The groove at the crank case half has to have a "spagetti"seal.
I use a "o-ring" string (2,5 mm) in the grove then I add some Permatex Form a gasket liquid gasket at the surface.
It has worked all the time..... no problem.

 

[racerone]

Post # 85 is very clear I think.

 

[gica]

Crowly Marine diagrams show Crankcase Cover Seal F698122 number 20 in the picture
When I opened it up it did show a red sealant like Loctite.

 

[gica]

Post # 85 is very clear I think.

Yes sir it is.
Just double checking not questioning. So you're saying the Loctite 518 is enough no need for the Crankcase Cover Seal F698122
And the same for the spacer plate at the bottom of engine that had the gasket on top and sealant on the bottom?

 

[gica]

I took all the parts off the engine to clean and when I got to the exhaust cover I noticed the plate behind it was not exactly straight. It has a bulge in the middle that goes on throughout the length
of it. Is it mandatory that the plate is flat? I will.show a photo tomorrow.

 

[topgun3690]

I took all the parts off the engine to clean and when I got to the exhaust cover I noticed the plate behind it was not exactly straight. It has a bulge in the middle that goes on throughout the length
of it. Is it mandatory that the plate is flat? I will.show a photo tomorrow.

Mine was like that on my old powerhead.....asked around and was told it was fine, not to worry about it. Even if you got it flat again it would distort over time they said.

 

[gica]

Mine was like that on my old powerhead.....asked around and was told it was fine, not to worry about it. Even if you got it flat again it would distort over time they said.

I was reading on it and apparently if and when you get water in the cylinders that could be the culprit. That's why I asked.
To me it looks beat as heck.
Can you use silicone of some sort on the gaskets of these parts? I would not trust it without.

 

[topgun3690]

I was reading on it and apparently if and when you get water in the cylinders that could be the culprit. That's why I asked.
To me it looks beat as heck.
Can you use silicone of some sort on the gaskets of these parts? I would not trust it without.

Mine looked just like that.....I used Permatex Optimum Gray with new gaskets....never had a problem. I agree, it looks bad...as long as there are no holes in the plate and it is sealed up good it should be ok. Maybe jerry or Nordin will chime in with their take on it.

 

[Nordin]

As long as there are no hole in the plate....no problem.
The plate will warp because of the high temperature from the exhaust it exposed to.
New gaskets and some liquid sealant to hold the gasket in place when assembling.
Your plate looks good in the pics.

 

[gica]

When you say liquid sealer
Can I use this one it's used up to 400 degrees, for gas, oil water etc

https://www.amazon.com/Permatex-80019-Aviation-Gasket-Sealant/dp/B000HBM3QQ/ref=asc_df_B000HBM3QQ/?tag=hyprod-20&linkCode=df0&hvadid=241895017383&hvpos=&hvnetw=g&hvrand=8173163593863276025&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9030954&hvtargid=pla-492732657309&psc=1

Or this one up to 500

https://www.amazon.com/Permatex-80062-High-Gasket-Sealant/dp/B000HBGHB8/ref=pd_aw_fbt_vft_none_img_sccl_1/140-8826662-3533718?pd_rd_w=E7VTU&content-id=amzn1.sym.1383228f-ab5d-4064-97d6-80297ffcccd8&pf_rd_p=1383228f-ab5d-4064-97d6-80297ffcccd8&pf_rd_r=DZXJ0RZ43B2S5EVFZY8X&pd_rd_wg=oClOW&pd_rd_r=0a4ae3a2-68c4-4892-9e6c-443dbbc77d7b&pd_rd_i=B000HBGHB8&psc=1

I can use it in more than one place.

 

[Nordin]

I think it will work, I use Permatex Aviation No. 3 form a gasket and it has always work in many applications.
In your case the purpose for it is to hold the gasket in right place when assembling the cover plate.

 

[gica]

It only works up to 400F I don't think temps go higher than that right?
I wonder if the red permatex for high heat would work around the exhaust gaskets? I am trying to make sure the knicks and scratches don't bleed out air. I always use the black ultra on cars don't see why it won't work here. It's a marine environment sure but it should work.

 

[gica]

Johnson / Evinrude " gel seal "----or----Loctite 518 ----Use nothing else.

Yeah thanks, I am using the Loctite on the 2 crank case pieces but on the separation plate when opened there was black silicon don't know if original. Everything else had nothing but gaskets. So I don't know much about the 518 or the gel as compatibility with gaskets but permatex I do know. The book has the Loctite and also shows the industrial sealant 750. There must be a reason for that. Right?

 

[gica]

What do you guys use to clean the crud off the exhaust tube. It is nasty and black. Can I use gas or diesel? I have a parts cleaner with a pump in it that I got recently it is not too big but it should accomodate this size engine. I need to know what to use for the aluminum that won't affect the cast iron cylinders. Diesel?