1964 Speedifour seized? I think so now.

[Evinrude Boater]

Was burning off gas before taking my boat out for the season and it siezed. Initially I thought I caught something in the prop but it was clean. Tried to turn it over with the pull cord but it was locked up. After it cooled it can be turned over by the recoil starter.
I haven't tore into it yet to see what the cause and damage is and I can't determine what it might be. I thought maybe the oil separated from sitting over a month but I did slosh it around a bit putting the tank into the boat. I used up another tank that was sitting for the same period with slow and WOT running with no problems. Maybe it overheated but I happened to be watching the tell-tale today as well as the exhaust relief. It seemed to be pumping well. The only thing I can figure is that the water pump flew apart and stopped pumping water rather quickly.
Where to go now? I'll be replacing the water pump but should I be inspecting the cylinders for scoring before trying to run it again? Or should I just run a compression test to see if there is a significant change?
I've got all winter.
By the way, I just finished the trailer two weeks ago completing this five year project to restore the boat, motor and trailer. Just when I think I'm done, I'm right back into it.

 

[lbentz]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

well, a compression test would be a good place to start. The best thing to do, is drain the carb before parking it for the winter. Running the gas out is also like running it out of oil too. If your compression is inconsistant between cylinders, then I would pull the bypass covers to get a visual of the pistons.

 

[Evinrude Boater]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

Running the gas out is also like running it out of oil too.

I thought that applied to injected systems, not pre-mixed. It didn't run out of gas when it happened though. There was no black ooze running out of the lower end when we got it on the trailer. I hope that's from shutting down after running it fast instead of idling at the dock and loading up.

 

[Chris1956]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

EB - Did it unseize after it cooled? If so, take a compression test. If all cylinders are 90PSI and even, you are probably fine. Those motors are pretty tough.

The oil will never settle out of the fuel mix, no matter how long you wait. I will guess that you connected straight gas to it.

 

[freddyray21]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

check compression first and see. Like it's been said if the compression is good make sure the water pump is good again before running it. I don't run the gas out of mine. I just run them with stable in the gas and they are fine in the spring.

 

[Evinrude Boater]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

Chris, after it cooled I could turn it over. The gas was mixed 50:1 with stabilizer. I was using up the remaining gas in the tank before storage. I'll do a compression check next week and get back to the forum.

 

[asdasc]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

When I get into late fall, I just start mixing Stabil in the gas so that when I am done for the fall, I am all set. With the Stabil in there, you don't need to drain the fuel bowl or anything, right?

 

[F_R]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

Is/was there any sign of overheating? Such as smoke, hot smell, burnt paint,....? How fast were you going when it siezed? Yes, I have seen many water pump impellers fail suddenly and cause catastrophic damage.

If it did overheat, you need to replace the head gaskets and exhaust cover gaskets, at a minimum. If it scored piston skirts, well you know what that means. You will be able to see the piston skirts when you get the exhaust covers off.

It could have been something other than overheating also.

Oil does not settle out of the gas. And if it can't run out of oil without running out of gas at the same time. If it could, there would be siezed motors all over the place from running a tank dry. Before somebody yells at me, yes a multi-carburetor engine can run without gas and oil in one or more cylinders. But yours only has one carburetor. And yes, it is possible for one side of that one carb to be plugged up, but you would have noticed poor performance before it siezed.

 

[lbentz]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

I thought that applied to injected systems, not pre-mixed. It didn't run out of gas when it happened though. There was no black ooze running out of the lower end when we got it on the trailer. I hope that's from shutting down after running it fast instead of idling at the dock and loading up.

Well, injection systems will inject oil even after the gas runs out, but the conventional 2 stroke engines will run out of oil, when they run out of gas, simply because it's mixed together. Burning out the gas in outboards is derived from an old myth. People don't generally burn out the gas in their weedeaters, chainsaws, or dirtbikes, but they do, in the outboards. Hmmmm, why is that?
The real reason people burn out the gas in the outboards, is to prevent gas from leaking out of the carbs, when they detach them from their boats and lay them on their backs. When it misses the first time, then it's best to shut 'er off. Even when you think you've burnt it all out, there is still a little bit that remains, so burning all the gas out is pointless. Leaving gas in your Speedifour throughout the boating season will not hurt anything, but before you winterize it, it's not a bad idea to drain it out the gas (onto a rag) by simply removing the drain plug at the bottom of the carb. Fortunately, with the invent of gas addatives, that is no longer needed.


Pretty much all motors will have all that black **** running out of the exhaust end, because that is burnt oil, mixed with unburnt and it's just a big mess. EWWWW!! Not nice for the garage floor, so be sure to lay a piece of cardboard under your motor.

The deal with your motor seizing up, may be something that has been developing for a long time. the main thing that causes motors to seize up, is scored pistons. There are three things that cause pistons to seize up and that is bad gas, lack of oil and overheating. You can get a good visual of your pistons, through your exhaust ports or intake ports.

A lot of people believe that you can run these motors on 50:1 mix, but I would not really recemend it on anything older than 1972. Sure....9.5 and bigger are fully jeweled, but the pistons really aren't designed to run on anything thinner than 40:1 unless the pistons are pretty well worn. A fouled plug, is much better than a scored piston. Sure people get away with running these motors with 50:1, but the first time the engine gets hot, it's done for. More oil also prevents less heat and friction. People often run the 7 1/2's, 5 1/2's and such, with 50:1 mix, but that is a major no no. These type of motors are a fricton type and should run on 24:1 or thicker.

Running more oil only prolongs the life of your outboard. This is your play toy......treat it like your baby.

 

[freddyray21]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

I have so many older motors and to keep from getting mixed up I will run them all on 24:1 unless it's a real old one then 16 or 8:1.

 

[Evinrude Boater]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

The gas I was using was used earlier in the year then I switched out the tank and put it in my small boat with a 1965 5 hp Johnson. It ran fine in that motor. Prior to the siezure we were running full out and all speeds in between just to use up the gas in the tank, not to run the engine dry. It was close to full throttle when it stopped. I didn't have the tilt lock engaged and the motor came up out of the water and skidded along the surface a few seconds as we slowed down. Scary!
This engine had peeling paint before I got it five years ago. Chances are it has overheated in the 40 years before I got it. I check the temperature of the engine with an infrared thermometer at the start of the season and this year I installed a tell-tale stream. While running I felt the stream temp and it was like washing your hands in hot water. Tolerable but a bit too hot. It ran flawlessly all year, except when one high speed jet plugged up. Last year I used 24:1 for the last tank of the year.
This winter I'll trace the high temp horn wire and get one hooked up.

 

[lbentz]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

Well, gas that's used for a 5hp, is definately safe for your Speedifour. That is typically mixed a little thicker anyhow, per instructions.

Your thermostat may possibly need replacing, if she's running that hot. If your motor is in nice condition, along with the boat, then she may be worth overhauling, if it ends up needing it. These are great motors and are pretty reliable.

I have a 1984 15hp Johnson that a former customer just gave me last month. The thermostat in it was seized for sometime, due to salt water corrosion. The last time he ran it, it got hot enough to discolor the head and locked up on him. I pulled the head and intake bypass covers and saw that each piston was scored in at least three places. OUCH!! Funny thing is, it still runs great, so it must not have locked up the rings in their groves (which scoring often does). This is usually what causes inconsistant compression readings, between cylinders.

This winter, I'll tear it down and put new pistons and rings in it. It's in prime condition, so why not. I'll get years of service out of it.

 

[freddyray21]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

those 15's are real good runners. I am also a fan of running too much oil maybe. Most of the motors I have are 24:1 so I seem to run all the motors on it even the 50:1.

 

[lbentz]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

yea, doing that, will only help prolong the life of them. What the heck, it may foul out plugs quicker, but it's better than a stuck/scored piston.

I think 24:1 is maybe only 3 or 4 onces more oil than 50:1 so it wouldn't be too noticable. Cheap assurance.

 

[Evinrude Boater]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

It doesn't appear to have siezed. I think the lower crankcase seal blew out and it stalled. I likely tried to pull start it with it still in gear and the lock out prevented it from moving. I remember shifting it into neutral later when it was out of the water.
The compression is 80-90 psi. The water pump checks out to be OK but when I pulled the lower end, the O-ring on the driveshaft was missing so I went looking for it up the exhaust shaft. The photos show what I retrieved. A steel ring and a piece of flexible plastic. The steel ring is bent from pulling it out. From what I see on the BRP parts diagram I can't tell what this is. I didn't find the driveshaft O-ring.
Assuming this is the lower seal, is it easier to pull the power head or exhaust shaft to replace the seal?

 

[Chinewalker]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

Hi EB,
I think it would be easier to pull the powerhead. You need to remove the inner exhaust housing from the outer and then powerhead from the exhaust housing.
I think I may have some used lower carbon seals and such if you need anything...
- Scott

 

[Evinrude Boater]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

Scott, what are carbon seals? I have a feeling I'll need to tear into it before getting a parts list together. I know the port side motor mount needs to be replaced. Can you PM if you have any? Is there anything else I should do while the power head is lifted out?
When I look up the exhaust tube inside the engine it looks like a connecting rod across the opening. What am I looking at?

 

[Evinrude Boater]

Re: 1964 Speedifour siezed

Re: 1964 Speedifour siezed

I have the power head sitting on its side in a wheel barrow. There's no easy way to work on the bottom. I can see the two bottom pistons through the exhaust ports and they look great. The bottom seal assembly is missing the retaining washer, part #305125 between the snap ring and the spring. The spring looked like it could come off around the snap ring. The steel washer, carbon seal and O-ring are there. I don't have the experience to know if the disintegration of the retaining washer could result in enough crankcase pressure loss to cause it to stall. Also, there's a puddle of oil on top of the adapter plate and I don't know if this is normal or excessive blow-by. The O-ring looks worn on the inside since it's flattened now.
Have I found the cause of the sudden stalling?

 

[1946Zephyr]

Re: 1964 Speedifour seized? Maybe not

Re: 1964 Speedifour seized? Maybe not

Well, it looks like I'll be working on a 75 hp Evinrude quite similar to this one. It should be fun. It looks to be in decent shape, so we'll see how things go.

 

[Chinewalker]

Re: 1964 Speedifour seized? Maybe not

Re: 1964 Speedifour seized? Maybe not

Hi EB,
The oil is normal (to a degree) on those motors - they're prone to puddling of unburned fuel in areas - their reputation as thirsty buggers is well deserved. The worn o-ring in the carbon seal could be contributing to excessive amounts of oil building up as it seeps out the bottom of the crankcase. Certainly won't hurt to replace it. Not sure if the washer is enough to kill the sealing properties, though.
I can see the rings in the one photo. Won't hurt to pull the intake port covers and make sure all the rings are loose in their grooves. Use a popsicle stick or the like so you don't scratch them. Be prepared to make some gaskets, though...
- Scott