1983 Evinrude 235 Head Gasket Replacement - Moderated Discussion Areas

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Author Topic:   1983 Evinrude 235 Head Gasket Replacement

Narragansett Outrage posted 07-05-2009 10:01 AM ET (US)
This is related to the overheating of my 1983 Evinrude 235 from another post (thermostat melt-down) - I've got a question concerning the replacement of the head gasket, so thought I should start a new thread.
After removing the port side thermostat, I found that the plastic parts had melted. The plugs, however, all seem to be fine.
Nevertheless, I'd like to just go ahead and replace the head gaskets while replacing the thermostats on both sides.
My question:
The Clymer manual is rather vague about how to replace these gaskets; is it possible to simply unbolt the head and replace the gaskets without removing the cover and the associated wiring? Any tricks I should be aware of as I attempt this?

While I'm at it, here's another thought: does anyone think that it would be beneficial while removing the thermostat (and the head for that matter) to inject vinegar into the water-circulation ports to remove any salt build up?
Thanks all,
Clive
Narragansett Outrage posted 07-09-2009 09:27 AM ET (US)
Any thoughts on this before I dig into it tomorrow? Hoping to be out on the water this weekend... although, if it keeps raining like this, I can probably just boat around my yard.
Whaler_bob posted 07-09-2009 11:26 AM ET (US)
You can remove the heads without removing the coils, etc.
The only rub is that you may need to torch some frozen head bolts- so at that point you'll have to remove the coils. I wouldn't remove the water jacket covers from the cyl heads unless they're leaking. They're a pain in the butt to get clean for re-gasket.
PS- have some Sea Foam or other carbon remover on hand and a razor scraper/wire brush to clean the heads and pistons while the heads are off. Also have plenty of carb cleaner on hand to wash down the pistons/cyl after de-carbonizing. Also, wire brush the cly head bolt threads then coat with grease prior to re-install. If the block threads look salty- run a tap through them. Torque head bolts in three steps- then re-torque after 10-20hrs use.
Good luck!
-Bob
Narragansett Outrage posted 07-09-2009 11:35 AM ET (US)
Excellent! Thanks Bob.
Clive
NewportMe posted 07-09-2009 02:21 PM ET (US)
While you have the heads off you may want to check to ensure that the heads are not warped. I overheated my 1989 evinrude 225 and the heads were slightly warped I had them machined back to true ( a couple thousandths ) and put in new gaskets and have had no problems for 2 years now.
Bruce
Narragansett Outrage posted 07-14-2009 07:55 AM ET (US)
I finally got around to removing the head yesterday.
This is the first time I've ever done anything like this, so when I got it off, I realized that I had no idea what a bad cylinder or piston looks like so I've taken some photos to show you.
http://i72.photobucket.com/albums/i199/oscarboscar/IMG000061.jpg
http://i72.photobucket.com/albums/i199/oscarboscar/IMG000071.jpg
To me, the cylinder walls don't seem to scored. There is certainly some carbon on the piston heads (which I assume I can remove with some decarbon treatment). When I grab the piston heads, I can wiggle them back and forth (not sure how much wiggle is OK, if any).
The only thing I notice is that burn mark on the lower part of the middle cylinder, underneath which you'll see that the aluminum casing is coming away from the steel cylinder wall. For anyone with experience in these things: is this thing ready to pack it in?
seahorse posted 07-14-2009 08:10 AM ET (US)
I'm afraid that you have major problems with that cylinder. It is pulled away from the cast iron sleeve and will never seal or transfer heat correctly.
Years back I saw a company's as that machines the cracked area away if it is not too deep and welds a collar around the sleeve. At the moment, I can't find any info on that procedure.
Narragansett Outrage posted 07-14-2009 09:05 AM ET (US)
Any cahnce that it may work for the rest of the season if I throw it back together?
Boo hoo.
Whaler_bob posted 07-14-2009 12:06 PM ET (US)
That block is shot Narragansett.... sorry.
It's already sucking in water from the separation area (see the discolored area on the cylinder wall just where the sleeve separation is- and if you look at the cyl head- there's probably a washed out clean spot adjacent to where the separation area is too) , and it's just going to get worse. People have used Marine Tex on areas like this- but it doesn't hold- the head gasket ring blows out- she sucks in more water- the rod bearings rust- and soon throws a rod.
If you can find a good used replacement block, you can probably use almost all of your old parts again- but you have to very carefully inspect the replacement block as sleeve separation is very common in these old blocks. Back when I worked at the Johnson dealership (in the early to mid 80's) the first thing we did to (older) used engines we hadn't serviced before was to pull the head(s) to see if it was even worth working on.
Narragansett Outrage posted 07-14-2009 12:51 PM ET (US)
Bob - bummer news. All this time spent changing the tank, the deck, the wiring, etc, and now this. Almost identical story to Jeff redoing his 22' Outrage.
So.. as I mentioned above, is it possible to just throw a new head gasket on there and maybe get it to run for the rest of the season? Or is this something where it'll just take another mile before it blows? Or is there no way of telling?
Clive
Whaler_bob posted 07-14-2009 02:31 PM ET (US)
When we pulled the heads- if we found something like that- we stopped all work and called the owner to come down have a look. In most cases- they bought a new engine from us- or a used one with a warranty. Can't tell you if it will last- we (as a certified Johnson repair facility who had to warranty our repairs) couldn't send something like that back into the field.
I have seen cases where separation has just started- and the owner was able to get the remainder of the season out of it- but in your case- the separation is fully developed and is peeling away from the cast iron cylinder sleeve already. I personally wouldn't chance using it in that condition and would start looking for a replacement block to put my good parts into.
The good news for you is there's lots of good blocks around for your vintage engine at reasonable (as compared to new) prices.
Narragansett Outrage posted 07-14-2009 03:14 PM ET (US)
Damn, damn, damn.
Well, I know this is going to sound like amateur-hour (and I do appreciate your input), but I think I'm going to try to shove some JB Weld in there and try to get her to run for the rest of the season.
Truth be told, the 235 gets horrendous mileage (perhaps 1 mile to the gallon), and I've been looking for a reason to get another motor. I can't see spending the amount I'd have to spend on repairing this one, only to end up with the same mileage.
Just going to make sure my Seatow membership is up to date....
Whaler_bob posted 07-14-2009 03:21 PM ET (US)
Well, as long as you know the risks then it's totally up to you.
Hope you get the rest of the season out of it- just be gentle with her (and don't venture too far out) ;-)
Narragansett Outrage posted 07-16-2009 05:03 PM ET (US)
Just in case I do come to my senses, do you have any recommendations on where I could buy a 235 block?
C.
Whaler_bob posted 07-17-2009 10:41 AM ET (US)
I'd start w/the local dealers & repair shops. Shipping on heavy items can be expensive. Failing that, do a Google search for "used outboard parts" and you'll see some of the big shops down in Florida have lots and lots of inventory.
Buckda posted 07-17-2009 10:57 AM ET (US)
Sorry to hear about your problems, but I don't think I'd be looking for a used block in Florida - too much saltwater use and too many hours!
I'd look to combine a fall "color" trip to see the leaves change across the upper Midwest. Western New York, Pennsylvania, Ohio, Michigan and Wisconsin shops probably have these blocks from owners who repowered their vessels with absolutely nothing wrong with the old motor other than it was old. Boats in this area are fortunate to see 50 hours of use a season - and many receive far fewer hours than that!
Plus, with the economy here in shambles, it is likely that shops are interested to move inventory.
Look around.
Good luck.
Dave

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Author	Topic: 1983 Evinrude 235 Head Gasket Replacement
Narragansett Outrage	posted 07-05-2009 10:01 AM ET (US) This is related to the overheating of my 1983 Evinrude 235 from another post (thermostat melt-down) - I've got a question concerning the replacement of the head gasket, so thought I should start a new thread. After removing the port side thermostat, I found that the plastic parts had melted. The plugs, however, all seem to be fine. Nevertheless, I'd like to just go ahead and replace the head gaskets while replacing the thermostats on both sides. My question: The Clymer manual is rather vague about how to replace these gaskets; is it possible to simply unbolt the head and replace the gaskets without removing the cover and the associated wiring? Any tricks I should be aware of as I attempt this? While I'm at it, here's another thought: does anyone think that it would be beneficial while removing the thermostat (and the head for that matter) to inject vinegar into the water-circulation ports to remove any salt build up? Thanks all, Clive
Narragansett Outrage	posted 07-09-2009 09:27 AM ET (US) Any thoughts on this before I dig into it tomorrow? Hoping to be out on the water this weekend... although, if it keeps raining like this, I can probably just boat around my yard.
Whaler_bob	posted 07-09-2009 11:26 AM ET (US) You can remove the heads without removing the coils, etc. The only rub is that you may need to torch some frozen head bolts- so at that point you'll have to remove the coils. I wouldn't remove the water jacket covers from the cyl heads unless they're leaking. They're a pain in the butt to get clean for re-gasket. PS- have some Sea Foam or other carbon remover on hand and a razor scraper/wire brush to clean the heads and pistons while the heads are off. Also have plenty of carb cleaner on hand to wash down the pistons/cyl after de-carbonizing. Also, wire brush the cly head bolt threads then coat with grease prior to re-install. If the block threads look salty- run a tap through them. Torque head bolts in three steps- then re-torque after 10-20hrs use. Good luck! -Bob
Narragansett Outrage	posted 07-09-2009 11:35 AM ET (US) Excellent! Thanks Bob. Clive
NewportMe	posted 07-09-2009 02:21 PM ET (US) While you have the heads off you may want to check to ensure that the heads are not warped. I overheated my 1989 evinrude 225 and the heads were slightly warped I had them machined back to true ( a couple thousandths ) and put in new gaskets and have had no problems for 2 years now. Bruce
Narragansett Outrage	posted 07-14-2009 07:55 AM ET (US) I finally got around to removing the head yesterday. This is the first time I've ever done anything like this, so when I got it off, I realized that I had no idea what a bad cylinder or piston looks like so I've taken some photos to show you. http://i72.photobucket.com/albums/i199/oscarboscar/IMG000061.jpg http://i72.photobucket.com/albums/i199/oscarboscar/IMG000071.jpg To me, the cylinder walls don't seem to scored. There is certainly some carbon on the piston heads (which I assume I can remove with some decarbon treatment). When I grab the piston heads, I can wiggle them back and forth (not sure how much wiggle is OK, if any). The only thing I notice is that burn mark on the lower part of the middle cylinder, underneath which you'll see that the aluminum casing is coming away from the steel cylinder wall. For anyone with experience in these things: is this thing ready to pack it in?
seahorse	posted 07-14-2009 08:10 AM ET (US) I'm afraid that you have major problems with that cylinder. It is pulled away from the cast iron sleeve and will never seal or transfer heat correctly. Years back I saw a company's as that machines the cracked area away if it is not too deep and welds a collar around the sleeve. At the moment, I can't find any info on that procedure.
Narragansett Outrage	posted 07-14-2009 09:05 AM ET (US) Any cahnce that it may work for the rest of the season if I throw it back together? Boo hoo.
Whaler_bob	posted 07-14-2009 12:06 PM ET (US) That block is shot Narragansett.... sorry. It's already sucking in water from the separation area (see the discolored area on the cylinder wall just where the sleeve separation is- and if you look at the cyl head- there's probably a washed out clean spot adjacent to where the separation area is too) , and it's just going to get worse. People have used Marine Tex on areas like this- but it doesn't hold- the head gasket ring blows out- she sucks in more water- the rod bearings rust- and soon throws a rod. If you can find a good used replacement block, you can probably use almost all of your old parts again- but you have to very carefully inspect the replacement block as sleeve separation is very common in these old blocks. Back when I worked at the Johnson dealership (in the early to mid 80's) the first thing we did to (older) used engines we hadn't serviced before was to pull the head(s) to see if it was even worth working on.
Narragansett Outrage	posted 07-14-2009 12:51 PM ET (US) Bob - bummer news. All this time spent changing the tank, the deck, the wiring, etc, and now this. Almost identical story to Jeff redoing his 22' Outrage. So.. as I mentioned above, is it possible to just throw a new head gasket on there and maybe get it to run for the rest of the season? Or is this something where it'll just take another mile before it blows? Or is there no way of telling? Clive
Whaler_bob	posted 07-14-2009 02:31 PM ET (US) When we pulled the heads- if we found something like that- we stopped all work and called the owner to come down have a look. In most cases- they bought a new engine from us- or a used one with a warranty. Can't tell you if it will last- we (as a certified Johnson repair facility who had to warranty our repairs) couldn't send something like that back into the field. I have seen cases where separation has just started- and the owner was able to get the remainder of the season out of it- but in your case- the separation is fully developed and is peeling away from the cast iron cylinder sleeve already. I personally wouldn't chance using it in that condition and would start looking for a replacement block to put my good parts into. The good news for you is there's lots of good blocks around for your vintage engine at reasonable (as compared to new) prices.
Narragansett Outrage	posted 07-14-2009 03:14 PM ET (US) Damn, damn, damn. Well, I know this is going to sound like amateur-hour (and I do appreciate your input), but I think I'm going to try to shove some JB Weld in there and try to get her to run for the rest of the season. Truth be told, the 235 gets horrendous mileage (perhaps 1 mile to the gallon), and I've been looking for a reason to get another motor. I can't see spending the amount I'd have to spend on repairing this one, only to end up with the same mileage. Just going to make sure my Seatow membership is up to date....
Whaler_bob	posted 07-14-2009 03:21 PM ET (US) Well, as long as you know the risks then it's totally up to you. Hope you get the rest of the season out of it- just be gentle with her (and don't venture too far out) ;-)
Narragansett Outrage	posted 07-16-2009 05:03 PM ET (US) Just in case I do come to my senses, do you have any recommendations on where I could buy a 235 block? C.
Whaler_bob	posted 07-17-2009 10:41 AM ET (US) I'd start w/the local dealers & repair shops. Shipping on heavy items can be expensive. Failing that, do a Google search for "used outboard parts" and you'll see some of the big shops down in Florida have lots and lots of inventory.
Buckda	posted 07-17-2009 10:57 AM ET (US) Sorry to hear about your problems, but I don't think I'd be looking for a used block in Florida - too much saltwater use and too many hours! I'd look to combine a fall "color" trip to see the leaves change across the upper Midwest. Western New York, Pennsylvania, Ohio, Michigan and Wisconsin shops probably have these blocks from owners who repowered their vessels with absolutely nothing wrong with the old motor other than it was old. Boats in this area are fortunate to see 50 hours of use a season - and many receive far fewer hours than that! Plus, with the economy here in shambles, it is likely that shops are interested to move inventory. Look around. Good luck. Dave