Crusty head and exhaust cover gaskets

[tboydva]

OK, I've tried to give this a good search, but all I could find is one where there was visible "burn" on the gasket(s). Here's perhaps a new question. I got an outboard for almost no cost. The guy had it stored since 2004 and go the boat from his dad when he passed (2002?). It was fogged and stored. He claimed his dad took good care of his stuff (the boat is a '69 and he re-powered in 1995). It's an Evinrude 60 (1995). I did a compression check and all cylinders were dead on 108 PSI (this without being run for 8 years). The motor is immaculately clean on external surfaces (and the powerhead). As I was going over it in order to work it over this winter, I noticed a little white crust on the head and exhaust cover gaskets. I've seen ones that are burnt and this doesn't look burnt or anything. Just like there is some small amount of seepage. So, as I have a working OB on my boat (was thinking of switching out this winter - my current one is an '83 johnson 60 in great condition - but without power trim/tilt which I would like to have for all the fouls in the Potomac River!).

So, my question is, should I replace the head and exhaust gaskets? Is this seepage a sign of some bigger problem (never noticed this on the 8 different OBs I've owned over the years)? I'm going to try and attach some pictures. I have the camera on macro and the surface looks worse than it is - mostly the paint looks brand new on the entire powerhead.

 

[Jeff_G]

Re: Crusty head and exhaust cover gaskets

What you are seeing is a mineral buildup from very small seepage between the covers. It is more unsightly than a problem. Eventually the gaskets could leak more or more corrosion could build up. Personally on my motors I replace the gaskets, but you don't have to. The only other problem I have encountered with this is the bolts will corrode a bit faster and eventually become a problem to take out. If you replace the gaskets make sure the surfaces are absolutely clean and flat. Put some Permatex Aviation Form a Gasket on the bolts before replacing them to seal them from corrosion.
Usually seen only in salt or brackish water.

 

[tboydva]

Re: Crusty head and exhaust cover gaskets

Jeff,

That was my suspicion. While there was no "leakage," my saltwater outboard (San Diego) accumulated a lot of scale inside, so I figured this might be the issue with my "new" one. The owner used it in the Delaware Bay and freshwater lakes - but I'm sure the mixed use still lead to some scale buildup. I'm refurbishing it and in no great hurry, so I believe I will take your advise and pull the head cover and exhaust cover and give the channels a good cleaning. The zincs look only slightly pitted, so I think this motor didn't do any major saltwater excursions. I'll add the gaskets to my carb kit and water pump kit order! Thanks for the help and rapid reply!

Tom

 

[tboydva]

Re: Crusty head and exhaust cover gaskets

So, I took your advise and decided to remove the exhaust cover (next the head cover). Thought the troubles I had with my '66 merc had to have been engineered away, but of course there was one bolt that couldn't be removed without taking half the cowling off! About a 1/16" is all I would have needed. I wonder if anyone ever thinks about this stuff.... Anyway, good news and bad. The good news is that the motor was as clean as I could possibly imagine! Almost no scale at all in the exhaust area (picture included)!!! The bad news, one of the bolts was frozen. A day soaking with penetrating oil didn't do the trick. Now I've got to drill it out (with my shaky hands) and hope the extractor gets it out. Drilling, tapping and helicoiling is something I'd sure rather not do! Thanks for the help so far...

 

[Daviet]

Re: Crusty head and exhaust cover gaskets

Did the bolt break even with the block or is some of the bolt sticking out? Maybe you can get some vice grips on it, apply a little heat, and see if it will break loose.

 

[tboydva]

Re: Crusty head and exhaust cover gaskets

The bolt broke off in the head... Once I get the old gasket material off, I may be able to grip it. Do you think I should try heating the block? The last time I disassembled a powerhead, I used a putty knife to get rid of the old gasket material. I have to read up on the best method. I've used an extractor before which is threaded counterclockwise. You drill a hole and it digs in as it turns. It's been years since I had to do this, but I remember it being a pain. I had to eventually use a helicoil. At least the inside looks really clean! Thanks for the tip.

 

[Daviet]

Re: Crusty head and exhaust cover gaskets

Two ways to look at it. The bolt is stainless and the block aluminum. Aluminum expands faster than stainless. If you heat the just the bolt, it will expand, let it cool and try the reverse drill bit. You could heat the block around the bolt and try the reverse drill bit while it is still hot. I have had success both ways. If all else fails you can use a heli-coil.

 

[jonesg]

Re: Crusty head and exhaust cover gaskets

If you use an EZ out fully expect it to snap off and don't expect to be able to drill an extractor, they are very hard.
I wouldn't put an extractor near a block.

Thread inserts are very simple to do.

 

[gazza2007au]

Re: Crusty head and exhaust cover gaskets

take the motor to a shop and get them to drill and retap the thread i just had all 19 bolts snap on my exhaust cover i tried a easy out IT SNAPPED!!!!! there crap mate dont do it... than we drilled the bolts being 19 bolts not all were going to be perfect end result? the block is no longer any good! if you do it your self be vary patient and careful

 

[tboydva]

Re: Crusty head and exhaust cover gaskets

Wow - now I might be in trouble. So if a pro does it, they carefully drill out just to the inner diameter of the threads, then retap it? I suppose the issue doing this yourself is making sure your drill bit goes in perfectly straight an cuts without any angle? Maybe I should try it with successively larger drill bits, then fall back on a helicoil if all else fails. I have a jig for my drill which would allow me to take a good angle (I think). I believe I'll forgo the extractor based on your inputs! Thanks for the help...

v/r
Tom

 

[gazza2007au]

Re: Crusty head and exhaust cover gaskets

seriously mate its one snapped bolt pay a shop $20 and they will do the job! it wont be worth your hassle trying to do it your self and as the bolts are a harder metal than the alloy casing the drill bit tends to drift we uses a centre punch and a bench drill and still didnt get the middle of the bolts as the drill bit bends slightly

 

[crxess]

Re: Crusty head and exhaust cover gaskets

If you can get ta grip on it, or weld a nut to the broken bolt, you can get it out.

HEAT is the solution. Only apply heat directly to the aluminum around the Bolt. Don't be afraid to get it a little red. Then work the bolt back and forth(in/out). Heat again if needed.

The bolts do not bottom out but are stuck by oxidation. Heat will finish the process by turning the oxidized material to ash and loosening the bolt.

 

[jonesg]

Re: Crusty head and exhaust cover gaskets

seriously mate its one snapped bolt pay a shop $20 and they will do the job! it wont be worth your hassle trying to do it your self and as the bolts are a harder metal than the alloy casing the drill bit tends to drift we uses a centre punch and a bench drill and still didnt get the middle of the bolts as the drill bit bends slightly

Wow you had the horror experience breaking 19 bolts.

Its true that drill shanks bend and wander, the trick is to use the punch but then start with a center drill in a press, center drills have very fat shanks and start the hole but only for the first 1/4 inch, then you go to the proper size drill but don't leave a lot of shaft outside the collet ( collets are much more accurate than a chuck)

and drills never produce a round hole no matter what, they always make an eccentric hole, if the hole desired is to be round but not threaded the only way is to use the proper size reamer, if its to be threaded then the tap will cut it round .

 

[tboydva]

Re: Crusty head and exhaust cover gaskets

Well, I can see this has happened to others! I think I have a tiny bit of the bolt sticking out - and will have just a bit more after removing the gasket. I'm going to try and first put a torch to the area and try working it back and forth. If that doesn't work, it'll be off to the machine shop I guess. I'm going to remove the head gasket too, so I'm going to wait for one of those bolts to shear too! They've been soaking with penetrating oil for a few days more than the exhaust... I'm wishing I had just lived with the small amount of deposits now - but at least I'll have the motor in top shape when I repower my boat (my '83 is still running strong - but I want the power trim/tilt). It will be good to have a spare...

I'll post my results.

TJB

 

[tboydva]

Re: Crusty head and exhaust cover gaskets

OK - I hemmed and hawed. $65 later, I had a machine shop drill out the old bolt and tap it a-new. I heard various advise on heating and the more I read, it seemed as though it might damage the coating(s) inside the water jacket. My brother in-law said he uses candle wax which penetrates into the bolt hole and frees it. I just couldn't bring myself to torch it and risk damaging it! Got her back today and it's ready to reassemble. Now I just have to scrape off all the old gasket material. THanks again everyone for the advise.

TJB

 

[tboydva]

Re: Crusty head and exhaust cover gaskets

OK, here's the latest! I cleaned up (what was needed for) this:

And this:

Here's the pistons buffed off a bit:

Here's the new paint job on powerhead:

Time to clean up the cowling, repaint and cleanup the mid-section/lower unit; then reassemble!

 

[AndyD]

Re: Crusty head and exhaust cover gaskets

Next time try some Kroil Penetrating spray and use an impact gun set to low torque, and spinn nack and forth until it frees up. I learned this the hard way many years ago after I broke about a dozen bolt heads off while overhauling an old 79 Merc 115. When I overhauled my 1.6 L Sea Drive I used the Impact gun and an awesome product called NCH Penefree (No Longer Made). Kroil is even better it can penetrate into a space as small as 1 mil (WD-40, PB Blaster don't even come close). It took a little time but I did not snap a single fastener and some were really stubborn!

The object is to get the product into the space between the bolt and block and apply shock to it while not applying the king of toque that would snap the head off. Keep respraying and applying shock and it will penetrate deeper and deeper. With patience you should be able to get every bolt out without breaking or stripping (remember to only use six point sockets, if you don't have one them go out and buy them before you start breaking the motor down) Know that just horsing on a ratchet or breaker bar will snap these stuck bolts EVERY TIME.