Damn Boat Motors

[Duckslayer100]

I would bet the carbs were plugged regardless. You have multiple issues I'd guess. Hold your bulb straight vertical and pump it to see if it gets hard. If it doesn't you have either a fuel pump issue. Or if fuel runs out the overflow in your carbs you have a float bowl issue. Only achieving 3000 rpm's means one of several things. Low/lack of fuel to the cylinders. This can be caused by multiple things. Or your rings are stuck on your pistons. linkage not opening carbs as far as they need to be. One other question. When you start it at home on the muffs did you put it in gear and make sure the prop turns freely?

Can I check this by taking the air box off and just looking in the carbs while I pump the primer?

 

[MathewsZman]

Does the primer bulb get rock hard and stay hard? (que matthews for boner humor)
HMMM , that's a question better suited for breeding hunting dog's section ??

 

[Yoby]

Fixing issues like these can be fickle. You fix 1 problem and another pops up. You said gas was 10 yrs old, but he had it running last fall?

Follow the lines. Is there a fuel filter from the internal tank? did the tank get cleaned out? If any particles were in there they could float up into the fuel pump. It sounds like you started by diagnosing the symptoms.

Best bet would to fun through the fuel system and clean it. Ensure the tank is clean, clean the fuel pump (new diaphragm, lines ect as needed), clean the carbs again, check spark plugs again. Each step ensure there is no other contaminants that could plug an port a result in a blockage.

I can't tell you how many times I have starts by cleaning out a jet only to re-open it and find more gunk in it.

 

[eyexer]

Can I check this by taking the air box off and just looking in the carbs while I pump the primer?

just pull the cover. you will see or smell the fuel running out of the carbs. slow idling those old two strokes causes rings to stick on a regular basis. I've overhauled engines that would start great, run to the first fishing place, fish for an hour then try to take off and the thing wouldn't get on plane. When they get hot the rings stick and loose compression. Then free up when things shrink back down. If you don't find the issue is a fuel problem run some "ring free" in your fuel as well as sea foam.

 

[Duckslayer100]

I should clarify that the old gas was in MY boat. Before I installed the motor, I pumped as much of the old fuel out and then put in 10 gallons of fresh stuff.

I'm sure he ran fresh gas. We took the motor off his boat and installed it on mine. He had a nice bass boat that he put a 70 Yamaha on, which is what it was rated at. That was the only reason he wanted to get rid of the Johnson, because he wanted more power.

 

[Colt45]

3) New spark plugs. That initially was what I thought was a problem, because the bottom cylinder was wet and the plug seemed pretty corroded. Replacing the plugs seemed to help, but apparently didn't fix the main issue/s.

I had this issue on my 9.9 kicker for years, bottom plug was getting wet, top one ran dry. I kept a mental run time in my head and every 8 hours of run time I would pull the bottom plug, either clean/dry it or change it out. If I didn't do that, it would eventually get so wet that the motor wouldn't even start, which sucks when you are on the water wanting to pull cranks.
I change the needle valve in the carb, talked to lots of weekend mechanics, and was never able to eliminate it. Finally, last fall I could not get it started at all so took it in. Mechanic said it was the ECM module that was bad, it wasn't firing properly and the bottom spark wasn't firing hot enough and that's why my bottom plug was getting wet.
After changing out the ECM module, it starts like a champ. I really haven't used it much yet for cranking or put a whole lot of hours on it, usually do more cranking in the fall so I am not certain at this point if my problem is finally solved or not. My kicker is a 9.9 Mariner.
Just thought I would let you know about the ECM may be faulty causing a goofy firing sequence or its not firing hot enough.
I am not a mechanic either so hope this makes sense, just trying to help you out.

 

[Yoby]

3) New spark plugs. That initially was what I thought was a problem, because the bottom cylinder was wet and the plug seemed pretty corroded. Replacing the plugs seemed to help, but apparently didn't fix the main issue/s.

I had this issue on my 9.9 kicker for years, bottom plug was getting wet, top one ran dry. I kept a mental run time in my head and every 8 hours of run time I would pull the bottom plug, either clean/dry it or change it out. If I didn't do that, it would eventually get so wet that the motor wouldn't even start, which sucks when you are on the water wanting to pull cranks.
I change the needle valve in the carb, talked to lots of weekend mechanics, and was never able to eliminate it. Finally, last fall I could not get it started at all so took it in. Mechanic said it was the ECM module that was bad, it wasn't firing properly and the bottom spark wasn't firing hot enough and that's why my bottom plug was getting wet.
After changing out the ECM module, it starts like a champ. I really haven't used it much yet for cranking or put a whole lot of hours on it, usually do more cranking in the fall so I am not certain at this point if my problem is finally solved or not. My kicker is a 9.9 Mariner.
Just thought I would let you know about the ECM may be faulty causing a goofy firing sequence or its not firing hot enough.
I am not a mechanic either so hope this makes sense, just trying to help you out.

I am trying to understand the mechanics of this. Water was coming in the exhaust?

I had an issue with my 6hp Johnson. I would swap plugs and decided I need to get to the bottom of things and pulled the head off. Turned out to be a gasket on the head had a poor seal. Cleaned, replaced gasket and torque to spec. no more water issues.

 

[Allen]

Yoby,
No, as I read it the spark wasn't hot enough to efficiently keep that lower cylinder from collecting un-combusted fuel. That's a tricky one.

 

[Yoby]

Yoby,
No, as I read it the spark wasn't hot enough to efficiently keep that lower cylinder from collecting un-combusted fuel. That's a tricky one.

Ahhhhh wet from unused fuel & oil (assuming 2 stroke)... got it. Sorry was thinking water obviously.

 

[Colt45]

Ahhhhh wet from unused fuel & oil (assuming 2 stroke)... got it. Sorry was thinking water obviously.

You got it, just fuel though as my kicker is 4 stroke........... hopefully the wet plug issue is behind me

 

[Davey Crockett]

Interesting topic, I wish I had read this 2 weeks ago. Last week my 50 hp mercury fouled the top plug , I spun it over and noticed the spark wouldn't jump but put 4 new plugs in and it fired right up and ran good so I thought I wasn't getting good ground when I checked for spark. Next time out it fouled the top two plugs so I blamed it on the carb. Gave it a good drink of sea foam and changed the plugs that were missing and it ran fine for a couple hours and fouled another plug. Put another new plug in but this time the cylinder didn't fire, No spark. Brought it home and checked it out and both the Stator and switch box are way out of specs. so ordered parts yesterday.

 

[Duckslayer100]

Well boys and girls, the time has come to inform you of the culmination of many months of wondering, researching and working.

I decided that I couldn't in good conscience bring the motor in to a professional to get worked on. I just needed to rip the carbs out again and see if maybe I didn't clean it well enough.

So I took them out, cleaned them again (took out the idle screws and some other ports that I hadn't noticed the first go-around), and put everything back together being sure to cinch down fuel lines good and tight. Then, just in case the angle of my driveway was messing with results, I parked the boat on the street before lowering the motor into a large plastic trash bin. It always ran better with the muffs on then in the lake, so I wanted to make sure the exhaust was under water to get a more accurate result.

Primed the bulb and it got nice and hard. Good first sign. Turned the key, choked it and BOOM...sucker fired right off!

I messed with the idle screws a bit until I got it close, then took it out for it's maiden voyage this weekend. She ran like a dream. Started right up, no hesitation or threatening to die, and it took off and had plenty of power. Plus, even after fishing for awhile, it started up again no problem.

So THANK YOU to everyone who gave me their 2 cents and helped me with this process. Too bad summer is already almost over, but I'm looking forward to hopefully getting it on the water at least once more before hunting season.

 

[Ericb]

Moral of the story keep your Johnson clean!

 

[3Roosters]

but did you catch any fish?? haha

 

[Duckslayer100]

but did you catch any fish?? haha

We did! Brought a single 14-inch eye home that my son split with his little cousin. If we would have had more than an hour to fish, we may have done better. But I was just happy that everything worked.

 

[WormWiggler]

Moral of the story keep your Johnson clean!

Well, what I got was if your Johnson ain't right, head down the street and put it in a big old tub......

beer....