Outboard motor.. 135hp '76 Evinrude, spark, gas, dead cylinders..

[Dabba]

Resposted from Marineengine.com. We are clueless..

My friend's motor runs great out of water, but wont go above idle in the water. Anyway, we pull the plugs, and facing the heads, the right side cylinders, those plugs are alot cleaner than the left side. The Lower right plug looks untouched. So We started trying to run the motor on 1 to 2 cylinders systematically to see if those cylinders were indeed dead. The motor will run on one cylinder on the left side. The top right, it will try to kick over but wont, the bottom right it just cranks, no kicking over. So we think the right two cylinders, espically the lower right arnt firing. They are getting spark. We also took those inspection covers off that gave access to the side of the cylinders. We tried cranking it and we had atomized fuel coming out of each. I'm not sure if its getting enough fuel or not, but we have fuel and spark but it seems like the cylinders are dead.. Any ideas? were dumbfounded.


I was thinking it could be the power pack, the plugs give a little spark but im just not sure how a good plug with powerpack should be sparking. We are just lost.. Thanks

 

[MIKESMONZA]

My Dad Had A Original V-4 Evinrude,1959 model "50 HorsePower"
>Fore Runner of that Motor you are talking about,,
We had that Motor from 1959 to 1968,,
no real Problemns
But Lost 2-3 Starter's Years apart
Thrown thru cover into the Water lol
From backfire's while we had it,,,,

Then in the Summer Of 1968,,
And After a Really Bad Back Fire,
it barely had any power,,
to get out of the Boat Slip to the Trailor,,

We got it Back to the House Checked Every thing out,

Changed Fuel, Spark Checked,,,Magneto was Hot,,lol "Finger Test"
hooked up water hose attachment,,,It Still barely ran,,,,
Then Removed a Side Plate,Leading from
,intake manifold from 2bbl carb?? or under Carb???
To Cylynder Intake for Air/Fuel delivery and Found a Broken Reed Valve,,

It Looks like a Piece of Stainlless,,,,
And is Springy,,One was Missing a Piece???

Efectively Killing one Side of Motor,,
With out it You have No compression,,?,,,It been awhile,,
So i Went to a Dealer And Bought a Replacement,,
actualy two,,, they wear out,,
,I hope this Helps,
Mike

 

[Dabba]

yeah, we opened up the side access port, right where the throttle body meets the cylinders. we cranked it and were getting fuel out of the t-body. we dont see anything like a reed in there. its sparking but im not sure if its sparking enough... any tips on checking that? all i can think is were not getting enough spark otherwise im stumped..

 

[Thunder]

Things to check
Reinstall the inspection plate.
First pull the plug wires or the coil wire so the engine does not start. crank it over and look at the front of the Carbs with the throttle open. If gas is spitting out of one of the carb(s) you have a bad reed valve. or you can pull a carb(s) and see the reed plates to see if any of them are broken.
If the reed valves are ok then suspect the ignition system. IIRC the 135s have only one powerpack and coil?

As for the spark. The spark should robust and blueish in color. If it is weak and orange the power pack or coil may be bad.

 

[Dabba]

My friend looked into the carb and said he saw the high rpm jet firing..Im not sure, im not good with carbs. The spark was blue, but certainly not livly. Looked kind of small, but then again i have nothing to reference it to.. I didnt even know gapless plugs existed..

 

[Thunder]

Did you check the compression? May have a blown head gasket.

 

[hunter29078]

Not sure about the 76 but I believe they had individual Coils or powerpacks for each individual cylinder. Might not be getting enough spark to each individual plug. Also you might want to try joining and posting on the hull truth. Alot of knowledgeable people on that sight when it comes to boat and motors.

 

[Dabba]

Im already on marineengine.com Compression is at 100 on all cyilnders. Were gonna replace the coils/power pack and see if that does it. Will keep you guys updated

 

[Fordum]

When I was growing up, I spent a lot of time on the water. I always used to see outboards running up and down the river with no covers on. When I would ask, they would tell me that it either ran better that way, or would only run that way. Never knew why. Most of the time they did not know either.
Years later, I was in a friend's outboard shop, and one came in that way. I asked if he knew why folks did that.
He said yes. It was because the exhaust manifold gasket was bad. If they left the cover on, the exhaust would fill up the cover and choke the engine out.

If yours won't run in the water, it might be that, but its a long shot.
Other thing to look for, is a bad fuel pump. I had one that would run fine on the barrel, but not on the boat. Turned out that I was setting the can up high next to the motor on the bench, low in the boat.

Of course, your setup is a built in tank, but if there is an angle difference, it might have trouble picking up fuel.
Otherwise, the main reason it won't run in the water is either back-pressure or the load on the prop. Probably back-pressure since you could still rev it in neutral. If its back-pressure, then the in the water/not in the water is probably a red herring. You just are not getting power.

I would suspect the fuel. The ethanol situation has been a disaster.
Do a search on my post " gas that will break your engine".

J.

 

[Dabba]

were gonna try the coils then powerpack. i suspect its load on the prop secondary to a bad cylinder. i grew up around boats and never saw em run without the covers. maybe its a freshwater thing? ill check bck and keep you updated