84 60 hp Johnson cooling system problem

[lmbr]

FYI, on YouTube I found a channel called "Dangar Marine" and he has several videos he posted about restoring an 80's model 30 hp Evinrude and these have been very, very helpful in allowing me to see what I need to know about a lot of this.

https://www.youtube.com/watch?v=_S1d-H9ZQLs&t=3s

 

[Bosunsmate]

Sounds like steady progress. If it was me id go one step further and take the head off and clean out in there.
You can put sandpaper on a sheet of glass and move the head on it in a figure 8 pattern. That gets rid of any warping that has happened to it over the years. Once its all shiny no high spots a left.
The headgasket is rather cheap and you wont need to do it again for years if things go as they routinely a meant too

 

[Bosunsmate]

Check the poppet valve next to the thermostat isnt warped from heat too, that opens up under high pressure at high speeds to dump lots more water through the system

 

[juno pierrat]

have gone thru an over heat on my 2cyl. removed water passage cover, all good, removed cylinder head cover, fairly clean, and finally the cyl head, found a hole in head gasket down by the thermostat, ether water was bypassing passages in head or cyl head cover, think i posted pics here, might check old posts,several years ago
and yes, cyl cover a pain to get off, easier to remove head.

also did tell tall mod, did mine at top under lifting eye (service alert shows a slightly different place), and i have a "multifunctional meter" (a induction tach with temp sensor), the sensor is on one of the middle cyl head cover bolts, gives readings very close to infra red gun, what I've found idles around 155 and at speed 115. system doesn't like 1800 to 2100 , temp go to 170. I know the 143 thermostat opening, but ive run 2 years now with mod and am happy. hope this helps in some way

 

[lmbr]

The valve above the thermostat had quite a bit of corrosion so I ordered a new grommet and spring (the spring was in 2 pieces due to corrosion). The plastic valve itself seems ok.
My original problem was no tell tale. I haven't run the motor enough to get it overheated so I think I'm OK there. From watching the videos it seems the tell tale is kind of seperate from the rest of the cooling system and there could be water circulating even without the tell tale showing it. But seems like the modification tell tale would show the circulation. I am replacing the thermostat and the valve parts since I don't know it the thermostat was opening. I'm really hoping the impeller and key fit because I'm thinking the worn key was keeping the impeller from pumping.
Didn't order a head gasket. This whole project is getting rather expensive. The boat is an 84 model fiberglass hull and the lakes I fish are full of stumps and I don't trust the strength of the hull. I really want to get everything working so I can sell it and upgrade to an aluminum boat. At 73 yo safety is my primary concern.

 

[Bosunsmate]

The tell tale should start pissing within about four seconds from start up. It is one of the earliest parts of the cooling system to get water and whatever the thermostat is doing at the time wont affect that one bit.
This impellor key sounds like a likely culprit.
Make sure you have the kill cord (lanyard switch) attached to you from the controls as if you hit something and get thrown about turning the motor off instantaneously is the safest way you want to be

 

[lmbr]

I already knocked a hole in an old boat and barely made it to the bank so I'm pretty cautious about that. And I was just easing along very slow. Guess I hit it just right.
Back to the repair. Probably should replace the head gasket since I'm right there now. Will take another week to get the part. I have spent weeks waiting on parts. Never thought getting the right part could be so difficult. Finding out that just because it's listed as the right part is no guarantee it is.

 

[lmbr]

Pulled the head this evening. All the water jackets look really clean considering it's an 84 model. So I really believe the problem has to do with the water pump. The impeller and the nylon key. The impeller that was in the motor when I started looked pretty good so I'm thinking the impeller key is the problem. Hope the one coming fits.

 

[Bosunsmate]

Plane the head on a sheet of glass or mirror with light sandpaper on it, you will be amazed as to how warped they get and arent noticeably so to the human eye. Warping can allow combustion pressure into the water jacket which reduces water flow

 

[lmbr]

Got another impeller today, doesn't fit. I measured the impeller that I took off originally and searched online until I found one that will fit the measurements. Hope this one does it. This one is listed for a 2 cylinder 40 - 60 hp. loopcharged small gearcase. Seems the key phrase is "small gearcase". This impeller stuff is getting expensive. Bought a kit first, then 2 impellers that don't fit and now another impeller and key. Did get some fine sandpaper, 320 grit, and a piece of glass today. Will work on that until the head gasket comes in and then start reassembly of the head and cover.

 

[oldboat1]

http://ww2.iboats.com/Gearcase/dm/cart_id.549345883--session_id.079922773--view_id.1539926

Check your model number. Seems like water pump selection should be pretty straightforward for the '84(?)

 

[jakedaawg]

Got another impeller today, doesn't fit. I measured the impeller that I took off originally and searched online until I found one that will fit the measurements. Hope this one does it. This one is listed for a 2 cylinder 40 - 60 hp. loopcharged small gearcase. Seems the key phrase is "small gearcase". This impeller stuff is getting expensive. Bought a kit first, then 2 impellers that don't fit and now another impeller and key. Did get some fine sandpaper, 320 grit, and a piece of glass today. Will work on that until the head gasket comes in and then start reassembly of the head and cover.

I wonder if you have an aftermarket pump, like a redhead or whatever that brand is.

you may want to bite the bullet and just buy an OEM pump. Takes all the guessing out. OEM=right parts for the job, every time. Remember "boating is cheap " said no-one ever.

 

[lmbr]

oldboat1 - I definitely used my model number when looking for parts. Seems like I know the parts diagrams by heart now.(Not really) I looked at quite a few suppliers. What I found out was that there are several variations of the pump. Many of the part numbers are obsolete or discontinued and I had to go thru "replaced by" over and over again.

jakedaawg - Replacing the pump would also require replacing the drive shaft as the shaft in my motor is 1/8" in diameter smaller.

This has been a very frustrating experience and I definitely am going to sell this boat and motor once I get it running and find something newer. I know that is no guarantee because I went thru a similar experience with an 02 Nissan 50 hp I had. It was a great motor but many of the parts for it were discontinued and no replacements available.

 

[oldboat1]

Did you try the link I posted? Maybe that pn is already familiar to you, though.

 

[lmbr]

Yep, already bought 2 of that pn. Both too big.

 

[racerone]

The earlier bigger gearcase may have been fitted on your motor .----Post pictures of old impeller along with new parts.-----Is od of impeller too big or the bore for the shaft ?----Are you buying parts " on line " or from a shop with " in depth " motor knowledge ??----What gearcase is on this motor ?----Standard or the " commercial " that uses the 3 cylinder gearcase ??----Time to consult your local dealer !

 

[lmbr]

Good news!

Reassembled the head and head cover. I have replaced the thermostat and pressure valve along with giving everything a good cleaning. Cylinders both looked really good. Found a replacement impeller wedge key that fits among the many parts I have purchased . Used a water hose to run water into the water tube and the tell tale worked just as it should. The first water pump kit I bought had the correct size impeller in it, but just the wrong type of key. The impeller that was originally in the pump was in really good shape and I was tempted to just reuse it but decided after all I have gone thru with this, I will just wait until I get the new impeller. Prior to this water pump issue, I had overhauled both carburetors, replaced the fuel pump, fuel lines, added a water separator, cleaned the fuel tank, (even added a fuel gauge), and rewired the boat completely. After sitting up for 3 years I needed to be able to trust it.

This has been a quite the project but been good for 2 reasons: First, I know that the motor has had a going thru and is in good shape, and Secondly, I have had quite an "on the job" education in outboard motors. (Which is a good thing.) Ready to get this wrapped up and get on the water. Lots of Crappie are waiting on me.

 

[oldboat1]

Appreciate the feedback! If comfortable with gauges, consider a temp gauge (surface temp sensor -- easy installation). In any case, good boating!