79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Not the cylinder walls. Keep the gasket remover off the cylinder walls completely. When you all done cleaning and there is no remaining debris, wipe the exposed cylinder surfaces with a clean cloth, then apply a light oil coating with a paper towel just before installing the head.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

What about the scratches in the attached cylinder (1st picture). They aren't deep in my opinion, but my opinion on this stuff isn't worth a penny.

And do I clean the piston head in the second picture? If so, with the same stuff as the gasket cleaner? Scrape it off? Or don't touch the piston head you idiot!

Thanks a bunch you guys! You're the best!

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

The cylinder wall in the left most pic looks pretty bad, but hard to tell how deep the wounds are. BTW, what was the compression value for this hole ... that will tell a lot about the condition of this hole?

Leave the piston tops alone. Clean by decarbing after assembly.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

I know the boat shop ran the compression test when the engine was cold. This is what he wrote down. 1 - 75, 3 - 100, 2 - 125, 4 - 125. I'm sure there's an order to those numbers that you guys are aware of, and hopefully he would write using the same standards.

When I'm standing at the back of the boat looking at the engine, the top left whole is the one with the scratches. Would that possibly be the 1 hole?

And, for my next step even with the scratches on the one cylinder. Should I got ahead and put new gaskets in, re-assemble in the proper sequence, decarb after assembly, then start it up and warm up, and then run another compression test?

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

If the 75 is from the cylinder pictured just above on the left, I don't think it'll come up much, especially since you didn't find any obvious signs of head gasket leakage. You might want someone with more experience to take a look before you close it up. The numbers before the compression values are the cylinder numbers. A shop manual or the mechanic could tell you which is #1, which typically stbd top, #3 is stbd lower, #2 is port top and #4 is port lower.

I need to read more carefully ... #1 is top right (stbd) standing behind motor and you say it's #2 with the deep scratches? Unless the mechanic got confused with the numbers, you may get lucky.

Looks like:
2 _______ 1
4 _______ 3

 

[jriegle04]

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

i would also check the bypass cover gaskets on that side. it is number 18, 19, 20 on the parts breakdown. http://www.crowleymarine.com/brp_parts/diagrams/33321.cfm

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

If the 75 is from the cylinder pictured just above on the left, I don't think it'll come up much, especially since you didn't find any obvious signs of head gasket leakage. You might want someone with more experience to take a look before you close it up. The numbers before the compression values are the cylinder numbers. A shop manual or the mechanic could tell you which is #1, which typically stbd top, #3 is stbd lower, #2 is port top and #4 is port lower.

I need to read more carefully ... #1 is top right (stbd) standing behind motor and you say it's #2 with the deep scratches? Unless the mechanic got confused with the numbers, you may get lucky.

Looks like:
2 _______ 1
4 _______ 3

I called the shop and verified exactly what you said, so maybe I am lucky. He said the worst one was the top stbd = 1. Looking at the gaskets now. I'm attaching the one that was on side 1/3. It was on the hotter side and it is clearly "bubbled" on the inside parts. Would that affect the compression that much? I looked at the cylinders again and didn't see anything that would change my mind. Hopefully lucky...I think I'll progress to the next step unless anyone thinks I'm wasting my time...going on vacation tomorrow, so looks like I can order the parts and possibly get to it when I get back.

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Looks like overheated and head gasket leaked. You will need to check the head for flatness. If not flat to within .002", you will need to surface the head (heavy glass plate with 300 to 400 grit paper on top will work). Surface with figure 8 motion until flat.

Then install head, etc. Good luck.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

BRP kit from any BRP (Evinrude) dealer or on-line. As TD suggests, you may want to blow out the cooling system. Compressed air or water applied to the water pump tube should do as well. Who knows where all that rubber landed?

I took the lower unit off again to make sure I had everything correct while I'm waiting for the head gaskets. I did notice some of the old impeller in pieces at the water intake. I cleaned all that out. Now I wonder how much is in the various parts of the engine.

Now, if I attach a hose to blow it out, what do I need to remove on the engine to ensure all the junk gets blown out? Right now the telltale elbow is off plus the tubes to the heads. Will that work? Or do I need to do more?

Can I do this with the heads off or should I wait?

 

[oldcat]

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

From looking at the first photo in the first series of piston photos there is some scoring that could indicate that the piston has gotten hot enough at some point to expand enough to start scuffing the cylinder wall.

When this happens the usual result is that aluminum from the ring lands gets "smeared" over the rings, essentially preventing them from moving freely in the ring lands and interfering with the ring's ability to both seal and to transfer heat from the piston to the cylinder wall.

Carbon deposits have also been known to "grab" rings but I don't think that is the case here.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

Re: 79 Johnson Outboard - Blown??? - Maybe not but Prostrate Trouble now???

Ok guys, here's where I'm at so far. Flushed the system by putting hose directly into the tubes that come out of the block (where the thermostats are...)...It did blow out several small chunks of old impeller out the copper tube. I made sure no water got in the cylinders...

Then, put new head gaskets on, new water deflectors, new water gaskets, new tell-tale outlet, new hose to outlet...torqued everything down using the manuals specs. attached the hose directly to the copper tube, good pee pressure so hopefully no more clogs, put spark plugs in...and then let it rip. Started right up...I let it warm up at fast idle for about 10 minutes. Hopefully thats long enough to get a good compression reading. Turned her off, pulled the plugs out and did compression test. Got 115, 120 on Strb side and 120 and 120 on port side. If I'm reading things right, that should be within the tolerance that everything is ok and I lucked out!!! For this white collar never took an engine apart kind of guy, I feel fortunate to have found this site and appreciate all your help.

Assuming I'm good with those numbers, I'll put the lower unit back on this evening and make sure the water pump is working...then back to the water maybe? Let me know if I'm good to proceed...and thanks again!

 

[ezeke]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Sounds good to me. Be sure to re-torque the cylinder head bolts after break in.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Read a little more on the manual last night. It talks about using Adhesive M on the gear unit and exhaust housing mating surfaces. Is that totally necessary? And if so, is there a substitute for this type of adhesive at an auto store. The only other stuff I have is Permatek Aviation Form A Gasket...

And is there a way to test the overheat warning buzzer?

 

[curiousB]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

What a great thread! Dumb boater you are dumb like Peter Falk as Lieutenant Columbo in the old TV series! Dumb like a fox.

Nice to see how the community walked you through what seems to be a happy ending.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Read a little more on the manual last night. It talks about using Adhesive M on the gear unit and exhaust housing mating surfaces. Is that totally necessary? And if so, is there a substitute for this type of adhesive at an auto store. The only other stuff I have is Permatek Aviation Form A Gasket...

And is there a way to test the overheat warning buzzer?

In addition to the above, how do I "de-carb" the pistons?

And to Curious B...that was a little before my time...not sure if thanks are in order, but thanks!

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Courtesy of Joe Reeves...
----------------
"1. OMC Moly Lube = Any anti corrosive lube/grease.

2. OMC Adhesive Sealant = Marprox Sealer 1000, also available as Boat Armor Sealer 1000. (or maybe 3M #847) or Permatex Form-A-Gasket Sealant 1-B (ezeke)

3. OMC Triple-Guard Grease (is this white lithium gease?) = This is OMC's anti corrosive grease. Evinrude color is blue, Johnson is green. This is not the white lithium grease.

4. OMC Gasket Sealing Compound = Regular gasket sealing compound. Comes in a can with a small brush in its screw off cap.

5. OMC Outboard Lubricant (is this 2-stroke oil?) = I have no idea what they're referring to here, or for what purpose.

6. OMC Needle Bearing Assembly Grease = Any anti corrosive grease.

Some have used 3M weatherstrip adhesive for OMC sealer M.
OMC Adhesive M is 3M Scotch Grip 847.

Also, test the horn by taking the tan lead free at the top aft of powerhead and touching the end to ground ... horn should sound w/ key on (motor not running). The tan lead goes to the temp sensor.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

I asked a couple guys in town, and they thought it sounded funny to use Adhesive when putting the lower unit back on. Am I not understanding this instruction?

"22. Apply OMC Adhesive M to gearcase and exhaust housing mating surfaces.

They thought it sounded funny to basically "glue" the lower unit on, but what do I know. This is an old boat and maybe that's the only way it stays together! If I do have to use adhesive, I know I can get Permatex Form A Gasket Sealeant 1-B, but not sure about 3M Scotch Grip 847...I live in a small town in the middle of nowhere! Will that work in this instance?

Also regarding "decarbing" the pistons. Is there a gasoline additive or what do I do? thanks again.

 

[wilde1j]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Look in the "Top Secret" File pinned at the top of the post list for decard instructions. You use stuff called Sea Foam available from NAPA and other auto parts stores. One or two cans should be plenty, depending on how much carbon build up there is.

Not sure about the mechanical arrangement on your motor ... most have a large soft foam gasket for the exhaust housing to lower unit which might use gasket sealant just to keep it (the gasket) from dropping during assembly. Apply just to the upper part that mates with the exhaust housing only. Weatherstrip adhesive should be available from any decent auto parts store or even a door and window installer. BTW, you're not gluing the lower unit on, in fact the seam between the mid section and lower unit is assembled dry, with no sealer.

Sounds like you're close to being back in business. Congratulations!

 

[Fl_Richard]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

The permatex gasket is more to insulate the parts and fight corrosion than to seal anything.

 

[adamjr]

Re: 79 Johnson Outboard - Blown??? - Update...took off head and attached pics...

Hey there dumb boater, you're not dumb at all. I think you should probably be all right here. Having never wrenched on a motor before you did some pretty complex stuff for a newbie. Even though I used to rebuild car engines in my youth and early 20's I fund some of the boat stuff to be challenging for no other reason then the fact it was new to me.

Congrats and I hope all goes well when you put the Johnnie back in the water.