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

[dumb boater]

As my name indicates, i'm a dumb boater! This boat has been in my family since new, and I'm the 3rd generation to use it....

I know absolutely nothing about engines, and limited mechanical abilities. (I sit in an office all day). Here's what happened...out on water about 5 miles from ramp...started hearing a loud sound by the throttle. Didn't know at the time is was the overheat warning sound! Been in the boat 30 years and it never did that before...

ok, so i'm worried about getting back to the ramp so i turn around and head back. I make it back with he warning sound still going off, and of course after i get back and look at the manual, i think oh #$?#$@!@!!!!! I should have stopped right away.

I also didn't look for water coming out of the engine for cooling...just slipped my mind...put it back in the water a week later to see if the streams of water were coming out...it wouldn't even turn over. Pulled boat back out and went home. Read manual more and checked the fuse...it was blown so i relaced that. I hooked up a hose to the intakes and started the engine. It did start, but seemed rougher than usual and a little smoke was coming out by the prop. No sreams of water so I'm pretty sure I at LEAST have a water pump issue.

Sorry for the length of this post, but i'm just a dumb boater that didn't recognize the signs i should have...feel like an idiot now...

If a motor is blown, will it still start? Based on what I've indicated above, what do you think my prognosis is?

 

[JB]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Your outboard will probably be okay once it gets a working water pump. Check the compression. If it is over about 60psi and within 15% give it a new impeller.

If not, it is fixable. Let us know what you have when you have done the compression test.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Your outboard will probably be okay once it gets a working water pump. Check the compression. If it is over about 60psi and within 15% give it a new impeller.

If not, it is fixable. Let us know what you have when you have done the compression test.

How do I check the compression? And what is an impeller? Sorry, I just don't know much about this stuff...

I do have an appointment at a boat shop next week, but if there's something I can do myself, I'm sure willing to try so I at least act like I know what I'm talking about when I take it in.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Your outboard will probably be okay once it gets a working water pump. Check the compression. If it is over about 60psi and within 15% give it a new impeller.

If not, it is fixable. Let us know what you have when you have done the compression test.

Have the boat at the shop now...compression tested at 75, 100 on one side and 125 and 125 on the other. It definately needs new water pump the mechanic said. He also felt that with the compression level on the one side, the odds of it running again may be slight. If it does run, he didn't think for very long. But he said he'll never know for sure. He said it is probably blown and maybe time for a new boat. Of course I'd like a new boat, but didn't want to buy one this year.

Do you think with those compression settings I should replace the water pump/impeller and hope for the best? Or am I thowing money at a lame duck? I don't do any mechanic type work and he said it was really difficult to get the lower unit off because it got so hot. To replace the water pump with labor is about $300.

I hate to put too much money in a 1979 boat, but I don't know. It's still in great condition on the inside.

 

[ryendube]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Have the boat at the shop now...compression tested at 75, 100 on one side and 125 and 125 on the other. It definately needs new water pump the mechanic said. He also felt that with the compression level on the one side, the odds of it running again may be slight. If it does run, he didn't think for very long. But he said he'll never know for sure. He said it is probably blown and maybe time for a new boat. Of course I'd like a new boat, but didn't want to buy one this year.

Do you think with those compression settings I should replace the water pump/impeller and hope for the best? Or am I thowing money at a lame duck? I don't do any mechanic type work and he said it was really difficult to get the lower unit off because it got so hot. To replace the water pump with labor is about $300.

I hate to put too much money in a 1979 boat, but I don't know. It's still in great condition on the inside.

those numbers are not great. older motor like that and that situation I wouldnt pay 300 for the water pump repair. Id try to find out why the one side has low compression prior to spending any money on it.

 

[daselbee]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Getting the lower unit off should have nothing to do with the fact that the engine got hot. He has given you true advice regarding the compressions and the future of the motor, but the water pump price is too high.
The part is 50 bucks or so, and he can do it in an hour in my opinion.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

If I could get a buddy of mine to help put a new water pump kit in, do you think it would be worth the $50 for the kit and a 12pack of beer for my buddy? I assume I have an hour of labor at $80/hr at the shop so far since it was so "difficult" to get the lower unit off. I think it's still off and I can tell them I'm going to think about it.

With those compression numbers, how likely is it that I'll get it working again? I know it got real hot (smoked some and smelled) that last time just before I pulled it out. I let it cool off for several hours and was able to start it later. It turned right over.

 

[ryendube]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

If I could get a buddy of mine to help put a new water pump kit in, do you think it would be worth the $50 for the kit and a 12pack of beer for my buddy? I assume I have an hour of labor at $80/hr at the shop so far since it was so "difficult" to get the lower unit off. I think it's still off and I can tell them I'm going to think about it.

With those compression numbers, how likely is it that I'll get it working again? I know it got real hot (smoked some and smelled) that last time just before I pulled it out. I let it cool off for several hours and was able to start it later. It turned right over.

oh itll run, but like poop. you have half the compression in 1 cyl and kinda low in another. the test was most likely done while the motor was cold aswell who knows what itll be like warm. could be a crack/warp(this will get worse as it heats up), failed gasket(pray its this and it the cheapest fix but unlikely after overheat) cylinder wall could be pooched../shrug. if you and your buddy can do it , do it. Also I agree with above poster what does over heating have to do with removing the LU? I must be missing something?

 

[dumb boater]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Thanks for the info. I looked at the Pump Kits with Housing here on iboats. Other than $1 difference, is Sierra or Mallory better?

 

[daselbee]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Thanks for the info. I looked at the Pump Kits with Housing here on iboats. Other than $1 difference, is Sierra or Mallory better?

Sierra kits are fine.

Get ALL those fasteners from the marine dealer who has it apart right now.
Very important. Some of those bolts are 15 bucks each (or more).
I think you should have seven bolts for L/U attachment to midsection, one special bolt for shift rod to shift linkage, the trim tab, and any bolts taken off when they took off the lower engine shrouds if they did that.

A couple of things to watch out for since this is your first one:

1.. Those impeller blades must sweep in the correct direction when the driveshaft turns clockwise. The impeller has a top and a bottom side. Look carefully. Oil that impeller up a bit with TCW-3 to make the assembly easier.
Do not get any gasket debris down inside the L/U under the water pump area. It could block the W/P input when the new pump begins drawing water.
The impeller key must be installed correctly, and you will see that the "top side" of the impeller blocks the key from riding up and out of the driveshaft flat.
2. Look up inside the midsection and take close note of a copper tube that is coming down from the top. That water tube mates up with the output of the water pump housing. You will see a black tube coming out the top of the housing. That copper water tube goes into the black output tube of the pump housing. It is hard to get it in there with such tight spaces as you slowly close the L/U up against the midsection. That output also has a grommet in it that only goes in one way. The taper of that rubber grommet goes "up" to easily recieve the water tube and seal the system there. Lightly lube that water tube grommet too.
3. You can help the re-assembly of the L/U to the midsection by temporarily installing a couple of threaded rods in the sides of the midsection, and using nuts to slowly pull the L/U up to it's mating surface. Once in place, remove the rods and install the bolts. Keeps you from struggling with the weight of the L/U as you try to align the water tube and the shift rod. You have to be smart when sizing the length of the threaded rods if you use them. You may not be able to get them out once everything is in place because of interference with L/U fins.
4. Use OMC gasket compound (Permatex aviation formagasket) on the L/U bolts to keep corrosion down.
5. As you guide the L/U up to it's mating surfaces, the shift rod will be protruding out the top of the midsection under the carbs. Align the top of the shift rod with the shift linkage while all is still loose to aid in making that connection easily. DO NOT TURN THE SHIFT ROD, as that changes it's length and you will not shift properly.
6. There is no sealer required between the L/U and the midsection.

Anything I leave out, guys?

FUN!

 

[Sherman]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

I would pull the head on the side and check the head gasket. That way you can take a look at the cylinder walls if they look smooth with no deep scratches and the top of the piston(s) look good put in a new head gasket and recheck the compression.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Sierra kits are fine.

Get ALL those fasteners from the marine dealer who has it apart right now.
Very important. Some of those bolts are 15 bucks each (or more).
I think you should have seven bolts for L/U attachment to midsection, one special bolt for shift rod to shift linkage, the trim tab, and any bolts taken off when they took off the lower engine shrouds if they did that.

A couple of things to watch out for since this is your first one:

1.. Those impeller blades must sweep in the correct direction when the driveshaft turns clockwise. The impeller has a top and a bottom side. Look carefully. Oil that impeller up a bit with TCW-3 to make the assembly easier.
Do not get any gasket debris down inside the L/U under the water pump area. It could block the W/P input when the new pump begins drawing water.
The impeller key must be installed correctly, and you will see that the "top side" of the impeller blocks the key from riding up and out of the driveshaft flat.
2. Look up inside the midsection and take close note of a copper tube that is coming down from the top. That water tube mates up with the output of the water pump housing. You will see a black tube coming out the top of the housing. That copper water tube goes into the black output tube of the pump housing. It is hard to get it in there with such tight spaces as you slowly close the L/U up against the midsection. That output also has a grommet in it that only goes in one way. The taper of that rubber grommet goes "up" to easily recieve the water tube and seal the system there. Lightly lube that water tube grommet too.
3. You can help the re-assembly of the L/U to the midsection by temporarily installing a couple of threaded rods in the sides of the midsection, and using nuts to slowly pull the L/U up to it's mating surface. Once in place, remove the rods and install the bolts. Keeps you from struggling with the weight of the L/U as you try to align the water tube and the shift rod. You have to be smart when sizing the length of the threaded rods if you use them. You may not be able to get them out once everything is in place because of interference with L/U fins.
4. Use OMC gasket compound (Permatex aviation formagasket) on the L/U bolts to keep corrosion down.
5. As you guide the L/U up to it's mating surfaces, the shift rod will be protruding out the top of the midsection under the carbs. Align the top of the shift rod with the shift linkage while all is still loose to aid in making that connection easily. DO NOT TURN THE SHIFT ROD, as that changes it's length and you will not shift properly.
6. There is no sealer required between the L/U and the midsection.

Anything I leave out, guys?

FUN!

This is probably a stupid question but what is the small black plastic piece and small white plastic piece for? It came with the Sierra kit...

I went to the evinrude site and reviewed a diagram of the gear case. I have a 1979 Johhson 115 HP, Model 115TL79R 1979.

Does the larger o-ring 73 sit directly on top of the Grommit Imp Housing 72 that is also rubber? This doesn't make logical since to me, but hey, what do I know! I also can't locate the piece 66 impeller seal in my kit??

And as for turning the shift rod...what if I did (again, a dumb boater), I think I put it back to where it was, but I can't remember for sure. How can I tell other than it not working when I put it back on?

And last but probably not the least...does the small gasket go direcly under the teeth of the drive shaft? The shop took it apart, so I'm very green at exaclty where things came from!

I did order a service manual, but of course the parts came before that!

And thanks for the help. This is actually kind of fun for this office idiot!

 

[daselbee]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

So you bought the sierra kit? Were there no instructions?
1. From your description, you may be talking about the impeller key when you refer to the small black and white pieces.
The impeller key goes between the driveshaft and the impeller, located on that flat area of the driveshaft. It goes only one way, and when in place creates the mechanical connection between the driveshaft and impeller. Without it, the impeller will spin on the driveshaft. That would be part# 57 on the drawing. They provide two to take into account different designs. You will only use one.
2. No, O-ring 73 goes on top of the driveshaft. The old one is probably still there. If not you will see the groove for it. Piece #66 should be there.
If not in the kit, you could re-use the old one.
3. If you turned the shfit rod, it must be reset to the proper height. You must get that height from a service manual, or maybe someone here can post it. Then you very accurately measure from the center of the shift rod hole at the top, to the mating surface of the gearcase. You would have to turn it in full turns to affect the length, so unless you did that, I would assume it is right.
4. I can't figure out "the small gasket under the teeth of the driveshaft" part. You talking at the top of the driveshaft, where there is a groove below the splines? If so, that's where the o-ring goes.

They take a lot of liberty on that drawing. The most confusing part is that they don't show the full length of the driveshaft, and that sort of displaces the parts from their true positions, if that makes any sense.

Dry fit it with no sealers to make sure you have it right. Be absolutely sure you have that impeller key in its location, and make sure you mate the water tube up to the top of the pump (outlet) when putting the lower back up.

 

[Dhadley]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Use an OE water pump kit. Change both head gaskets. Change all 4 deflectors once the heads are off. Most likely the low compression on the one side is due to a blown, or partially blown, gaslet. Comperssion should be no greater than 15 lbs different between high and low. If the compression ends up consistant on each side but different side to side, check to make sure you have a matching set of heads.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

So you bought the sierra kit? Were there no instructions?
1. From your description, you may be talking about the impeller key when you refer to the small black and white pieces.
The impeller key goes between the driveshaft and the impeller, located on that flat area of the driveshaft. It goes only one way, and when in place creates the mechanical connection between the driveshaft and impeller. Without it, the impeller will spin on the driveshaft. That would be part# 57 on the drawing. They provide two to take into account different designs. You will only use one.
2. No, O-ring 73 goes on top of the driveshaft. The old one is probably still there. If not you will see the groove for it. Piece #66 should be there.
If not in the kit, you could re-use the old one.
3. If you turned the shfit rod, it must be reset to the proper height. You must get that height from a service manual, or maybe someone here can post it. Then you very accurately measure from the center of the shift rod hole at the top, to the mating surface of the gearcase. You would have to turn it in full turns to affect the length, so unless you did that, I would assume it is right.
4. I can't figure out "the small gasket under the teeth of the driveshaft" part. You talking at the top of the driveshaft, where there is a groove below the splines? If so, that's where the o-ring goes.

They take a lot of liberty on that drawing. The most confusing part is that they don't show the full length of the driveshaft, and that sort of displaces the parts from their true positions, if that makes any sense.

Dry fit it with no sealers to make sure you have it right. Be absolutely sure you have that impeller key in its location, and make sure you mate the water tube up to the top of the pump (outlet) when putting the lower back up.

Yes I bought the Sierra Kit, and it came fast from iboats...only a couple days by mail. But, the kit had absolutely no instructions, so I'm winging it totally from looking at parts diagrams...

1. On the key...I thought that's maybe what the plastic deals were. I used the metal pin from the original so that should work.

2. See attached picture where I put the small o-ring on top of the drive shaft in the grove...I assume I'm in the right spot.

Regarding missing piece 66, would that part only be included with certain types of casings? I took a picture of the old and new casings and posted it here. The old one appeared to have this piece. There is no place to put one on the new casing. It has tabs in it or something that go flush against the driveshaft. See the pic.

3. Does anyone have a manual out there that can help me with the exact measurements for the shift rod? I have a manual on the way, but of couse I'm not patient!

4. Small gasket under the teeth was my attempt at referring to the o-ring on top of shaft. BUT, I have another o-ring that's larger than that one that I don't have a clue where it goes. Is it possibly an extra part? Or does this possible go between the Cover (part 70) and the casing? or where?

Thanks!

 

[daselbee]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Looks good so far, but I am not there....
Sometimes the kits have parts not needed for various applications. That may be the case regarding that seal. I would look carefully for grooves, indentations, slots, etc that are the same size as that seal, and possibly determine fit that way.

I do not have the shift shaft length.

 

[dumb boater]

Re: 79 Johnson Outboard - Blown???

Re: 79 Johnson Outboard - Blown???

Looks good so far, but I am not there....
Sometimes the kits have parts not needed for various applications. That may be the case regarding that seal. I would look carefully for grooves, indentations, slots, etc that are the same size as that seal, and possibly determine fit that way.

I do not have the shift shaft length.

Thanks daselbee...I wanted to make sure I wasn't missing anything, so I pulled the casing off one more time to see if I missed any grooves. The plastic casing slid off from the metal cup when I pulled it off, and what do you know there was a nice groove for a seal! The metal cup was already in the casing when I got it, so I thought it was pre-assembled or something.

So I've now got a water pump ready to go...I slid the LU on with the help of my daughter, and now I'm having trouble getting the shift rod back into the slot where the screw goes through...needless to say I can't get my hand in there. Is there a trick? And should it be left in neutral, reverse or forward?

Thanks again for you help!

 

[dumb boater]

Re: 79 Johnson Outboard - New Water Pump/Impeller - Has prostrate trouble??

Re: 79 Johnson Outboard - New Water Pump/Impeller - Has prostrate trouble??

Ok, I got it back on...all bolts and everything hooked up. Put on ear muffs and started the engine. Only get a dribble out of pee hole. Is that all it's going to do with muffs, or do I need to check something else?

 

[wilde1j]

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

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

The key your motor uses is a metal key, rather than the plastic eccentric locking cam, and the Sierra kit may not accommodate it correctly. Did you old impeller have a keyway slot, rather than a flat area? The impeller may be rotating on the drive shaft. As DHadley suggested, A BRP kit would remove all uncertainty AND they come with instructions. I personally don't like the aftermarket water pump kits, especially after having the center hubs of impellers come loose after a week or so on more than one motor. The vendor will go unnamed! You did save a few bucks, though.

 

[dumb boater]

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

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

The key your motor uses is a metal key, rather than the plastic eccentric locking cam, and the Sierra kit may not accommodate it correctly. Did you old impeller have a keyway slot, rather than a flat area? The impeller may be rotating on the drive shaft. As DHadley suggested, A BRP kit would remove all uncertainty AND they come with instructions. I personally don't like the aftermarket water pump kits, especially after having the center hubs of impellers come loose after a week or so on more than one motor. The vendor will go unnamed! You did save a few bucks, though.

I turned the shaft with my hand and the impeller was spinning. I did use the metal key pin with it and it seemed to fit in with the impeller fine, but I'm new to this and maybe when it spins fast it loses it's connection. Heck I don't know. The shop told me there was no impeller left when he pulled it out...now that's old and its amazing the motor probaby even works. Where would I get a BRP kit? Or is there something else I should do?