Anyone want to take a stab ad diagnosing this engine? Video inside.

[RaisedByWolves]

95 25hp evinrude. Will not idle and is very hard to start.

Compression is 110/110, carb was just cleaned as well as coils swapped for ones that tested better than original and good wires swapped for bad. Motor has slight water leak out of the cooling jacket gasket near lower cylinder. It also cooked the impeller and plastic pump body while running in a tank.

Not sure if thermostat is working or not but the tell tale never gets hot.

I have only had this motor for a few weeks and it was a mess when I got it. It is a bear to start but was running OK the first time out. Second time out it was making a banging sound, Kind of like a miss but worse and it went up/down with throttle.

Then it ran fine later in the day after coolng off for an hour or so, hence me swapping the coils/wires.

Then I took it out and this was all it would do.

First vid, Throttle plate is open and timing cam not quite on the stop. Moving the timing cam around while running didnt change anything.

https://youtu.be/Dh8XGl0kUEQ

Second vid, more poor running, tell tale and exhaust stream.


https://www.youtube.com/watch?v=HqMkioLECg8

 

[flyingscott]

Check spark, it sounds.like that motor is.running on one cylinder. Spark needs to jump 7/16" gap. You may also.want.to re check your compression.

 

[tpenfield]

RaisedByWolves I worked with a guy who was raised by wolves

As for the outboard, it sounds a lot like my Johnson 4.5 hp. If all pans out on the spark, I'd go after the carb & fuel supply.

 

[racerone]

Water out of the tell tale does NOT go through the motor.-----It is an indicator for the water pump working or not.----It does NOT tell you that the motor is cooling properly.----What is your starting procedure ?----Using the primer pump on the motor properly ?----And check for spark on both leads too.

 

[RaisedByWolves]

I can’t get it to start easily via the suggested procedure in the manual, it will be flooded. I’m actually questioning weather the enrichener is working properly or letting fuel pass when it should not.

Before rebuilding the carb, squeezing the bulb too much would cause fuel to squirt into the carb via I think the upper enrichener barb on the top rear of the carb. The itty bitty one.

This stopped after the rebuild but it still does not like to idle. I melted the pump running it in a barrel and the only time I could get a good idle was when it was hot with no water pumping.

Im also wondering if it getting hot finished off the leaking water jacket gasket and is now flooding the lower cyl(near the leak) as the poor performance happened right after that and there was what appeared to be water in the gap on the plug when I checked for fouled plugs.

I suspected the water was just splashed on there from outside of the motor but now I wonder.

Could a blown gasket have sent exhaust through the cooling system and caused the pump to burn up?

 

[RaisedByWolves]

Ok went out today when I got home and pulled both plugs and yep, the bottom one had water in it.


Pulled the head and I think my suspicions about burning up the pump with exhaust gasses were correct.

 

[oldboat1]

Replace the water pump before further running. Replace the head gasket after resurfacing the mating surfaces; torque to specs, and torque again after running. If the top of the head is too hot to touch, the motor is too hot. It should be running at approx. 140F if you have a heat gun for testing. 160F is overheating.

You may have further damage due to water in the cylinder(s), but I would do the above and test it. Hope for the best.

 

[RaisedByWolves]

Got all new gaskets, t-stat, spring and washer, replaced the pump and surfaced the head.

Hopefully this will solve some of the issues I was having.:cold:

Just for effect, here’s a pic of the pump I removed.

shoot pic are too big

 

[RaisedByWolves]

Fixed the pic.

The stainless inner ring is spus about a quarter turn.

Also a pic of the top of the head showing carbon in the water jacket.

Is that normal?

I got it back together tonight and checked the compression and got 135/135. Then I went to start it ready for a fight and it fired on the first pull using the recommended starting procedure and.......it even idles!

Now I need to get it on the water and set the carb for proper idle under load.

 

[racerone]

This pump was running dry at some point.----Extreme heat will melt the plastic and the cup rotates.----Needs a new pump housing.

 

[RaisedByWolves]

As god is my witness that happened with it running in a large garbage can.

The pump and impeller were replaced last fall and I had it out twice this year last time being the day before it went TU.

Hence my crazy theory on the blown head gasket forcing the water out.

Is the carbon in the water jacket normal?

Does not seem like it should be there.

 

[racerone]

The impeller ran dry !!

 

[Fed]

As god is my witness that happened with it running in a large garbage can.

But was the water level well & truly above the pump and not just covering the intakes?

 

[Joe Reeves]

You know where the water pump is located.
The water pump is not self priming.
In the water, test tank, trash can, whatever... the water must be completely above the pump housing.
If the water pump is not submerged, the pump will draw air, and the exhaust blast will destroy the pump housing etc.

The slow speed adjustable needle valve does not require a load to be tested upon... in gear, under high throttle, has nothing to do with the slow speed adjustment. It can be adjusted quite satisfactory running in a large trash can, as follows.
********************
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
********************

 

[RaisedByWolves]

Thanks for the helpful input Joe, while it runs counter to the manual(if I’m reading it correctly) I’ll try that.

As to your sig line, can anyone tell me if carbon should be in the water jacket?

Yes the pump was submerged, but I found much of the missing head gasket in the space under the water jacket and really can’t fathom how it got there other than exhaust gasses.

ETA: If you look at the pic of the back of the head you can see a tiny portion of the debris that was in there along with gooey black residue.

When I removed the lions share of this it was clearly head gasket material.

 

[Joe Reeves]

Thanks for the helpful input Joe, while it runs counter to the manual(if I’m reading it correctly)

I'd appreciate it if you would take the time to explain that statement. What did I have to say that was "counter" to the manual?

 

[RaisedByWolves]

I'd appreciate it if you would take the time to explain that statement. What did I have to say that was "counter" to the manual?

2-63 covers the procedure as I understand it and states that the final adjustment be made in water under load.

Why do people here get so defensive?

 

[Joe Reeves]

WOW!..... 2-63 huh?, Really?... I'll need to buy a manual to read up on that!

Defensive? No, not really. Just wondered what purpose that mention served.

 

[RaisedByWolves]

WOW!..... 2-63 huh?, Really?... I'll need to buy a manual to read up on that!

Defensive? No, not really. Just wondered what purpose that mention served.

It just differed from what I read and seemed much easier. I know a lot about a lot of things and could make you an entire outboard from raw stock(Toolmaker), but the link and sink and their interactions have me dumbfounded and this motor is a mess, so I’m very by the book atm rather than seat of the pants like the stuff I do understand.

Will set it up correctly in the barrel today and hit the water tomorrow.

 

[RaisedByWolves]

Ok, went out on the lake today and the motor starts and idles beautifully!

But now it has learned a new trick.


Runs fine and the boat gets up on plane, but then it just falls on its face after 40-50 seconds.

This was the first time.


https://www.youtube.com/watch?v=UwMU...ature=youtu.be



Then after fishing for an hour or so it ran fine for a minute but then did it again and I got it on video going from 20mph ish do just falling on its face and bucking.

Right near the end of the vid.

https://www.youtube.com/watch?v=cAeJ...ature=youtu.be


Fuel issue?

Bad seal?


I pumped the ball while running and got no change when it was doing this.