One dead cylinder 115 Hp

[bobbelser]

I have a 1975 115 Johnson Model # 115ETL75E only running on 3 cylinders I know this from pulling plug wires while running, number 3 makes no difference at idle or high idle. This motor has not been running for about 3 or 4 years, I have run at least 10 gal. of gas through it with seafoam added after I bought it. It has 120 to 125 lbs. compression on all 4 cylinders I have tried so far to switch plugs from good cylinder to #3 problem stays at #3 also tried switching coils problem stays at #3. Is it possible for the reed for this cylinder to be stuck shut causing this and if so how can I get it freed up with out tearing it down. I am going to try decarbing it tonight with seafoam if that don?t work any suggestions. I don?t have a manual yet for this motor I bought it on a bass boat to put it on my pontoon when I get it running right.

 

[tashasdaddy]

Re: One dead cylinder 115 Hp

don't do the decarb, till you get that cylinder firing. just a waste, as it will not clean the cylinder.

if i'm not mistaken the top carb services the top cylinders, the bottom. right side, right side, left, left. it is a basicly 2 carbs in one. independent orifices for each cylinder. i think i would investigate the orifices for that cylinder. sitting that long, i would consider rebuilding both carb. you can see diagram, by following the prompts here. http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

you will see that there are 2 slow speed and 2 high speed orifices, one on each side.
http://forums.iboats.com/showthread.php?t=244013

 

[SKEETR]

Re: One dead cylinder 115 Hp

Try moving the plug wires as well. As far as the reeds go, I'd look elsewhere for now. Do you have spark on #3 or is it just not dropping rpm when the wire is pulled?

 

[bobbelser]

Re: One dead cylinder 115 Hp

I have spark on #3 it does not effect the motor when I pull the spark plug wire the other 3 cylinders do quiet a bit, both at idle and high idle.

When I switched the coils I switched the plug wires also.

Thanks for the replies

 

[SKEETR]

Re: One dead cylinder 115 Hp

I would first go the fuel delivery route as suggested by tdaddy. Have you tried pulling the plug wire at any rpm above idle? Either way I'd eliminate the fuel part of the equation before suspecting the power pak.

 

[iwombat]

Re: One dead cylinder 115 Hp

Let's beat the horse until it's really dead . . .

Just how are you determining that you've got spark on that cylinder. Are you using a spark tester w/ a 7/16" gap? If not, you can't be sure that it's sparking under load.

 

[bobbelser]

Re: One dead cylinder 115 Hp

With the motor running I stuck a screw driver in the plug wire and held the shaft 1/2" to 5/8" from the end of the plug and could see the spark and hear it snap.
I have had the motor running to about 3,000 RPM and it is the same no effect when I pull #3 wire.

 

[ezeke]

Re: One dead cylinder 115 Hp

If you are running with no fuel to that cylinder then you are also running that cylinder with no lubrication. I would prepare for the worst or rebuild the carburetor. I definitely would not run it again.

 

[bobbelser]

Re: One dead cylinder 115 Hp

I have run about 10 gal. of fuel through it on the water since I bought it, it does pretty good at running speed just won't idle right, and I rechecked compression last night when I found this cylinder wasn't working and it is still 125 lbs.. The plugs on all four cylinders are wet when I pull them after running. I am just a shade tree machnic I used to work on old cars, but this just has me baffeled.

 

[tx1961whaler]

Re: One dead cylinder 115 Hp

There is spark and compression confirmed at the cylinder, and the spark plug has been confirmed good, so all that's left is the fuel part of the equation.....so it souds like it's time to take the carb off and rebuild it.

 

[bobbelser]

Re: One dead cylinder 115 Hp

I also think all it could be was fuel I will work with it this weekend and let you all know

Thanks for the ideas

 

[tx1961whaler]

Re: One dead cylinder 115 Hp

Do yourself a favor and take a few pictures of all of the linkages and springs before you take it apart.......and hopefully you have a good manual for the engine.

 

[cdoliver]

Re: One dead cylinder 115 Hp

you could test the fuel problem by spraying premixed fuel in the throat of the carb that supplys fuel to that cylinder while its running. If it picks up it is definately the carb... or reeds... most likely carb.

 

[cdoliver]

Re: One dead cylinder 115 Hp

if that motor hasn't been running for 3-4 years and you haven't cleaned the carbs... you are going to find some gummed up jets for sure...

 

[bobbelser]

Re: One dead cylinder 115 Hp

You guys were right it was the fuel. I pulled the bowl drain from that side and the fuel just barley ran out I pulled the bowl drain from above it and it pored out. I used some choke cleaner to spray into both the high and idle jets then when I started it I could tell a difference right away. Also ran great on the water. It is on the back of my pontoon 24' tracker party barge now I just need to finish hooking everthing back up and get it back in the water.

Thanks again for all the replies.