And then it died

[R Willis]

I have a 96 model, 25hp Johnson on a 14 flat bottom. It was sitting up for a couple of years.
I got it running and put it in the water and it would not run over mid throttle.
I put a carb kit in and it seemd to run fine. GPS speed was 23-25mph. I figured that must be about right.
The other day I installed a tach for it. I used the factory wiring on the motor control, set the tach at 6 pulses.
Today I put it in water. It started out running about like it did when I put the carb kit in, it was 24mph, but at full thottle the tach was only showing 3800 rpm. I was experimenting with weight distribution and relocated the fuel tank to the midship. This is a new 12gal tank, hose etc.
Started out again and ran about the same, then started bucking like it was running out of fuel. Checked the vent and it was open. Swapped fuel hoses, no change.
As i was heading the back to the dock it began losing rpm, down to 3200. by the time I got back to the dock (3miles) it was barely running and eventuall died. It will start and slow idle but will die under load.
There is a new filter in the gas line between the tank and engine.

Could this be the fuel pump? Looking for suggestions rather than just throwing parts at it.

Thanks
RW

 

[Cofe]

Re: And then it died

I am suspecting the high speed jet is getting plugged up.
On the side of the carb bowl there is a screw with the high speed jet behind it. Remove the screw and use a small wire to clean out the jet.
Your motor symptoms could be many things, but I would try this first before moving on to more costly choices.

 

[Chinewalker]

Re: And then it died

Did it overheat? Was it pumping water? What are your compression numbers?

 

[R Willis]

Re: And then it died

OK, here is the latest... it may be a little long but I need to provide all the info I can in hopes of figuring out what is wrong with my motor.

after original post... I read Chinewalkers reply and realized that I had not checked for water flow when the motor was acting up. At the time it gave me no indication of being hot, but this moring I did a compression test first thing, both cylinders 140 plus, I guess this is OK.
Put in new spark plugs, Hooked up water and started the motor, it was pumping water and looked good. Idle was fine and would pick up rpm.
Took it to the river. It ran fine for about 3 minutes then lost power again, rough idle, would not accelerate above maybe 1500 rpm without stalling.
Loaded the boat, went and got a fuel pump kit. Installed the kit, I did find that one of the fuel pump check valves was bad.
With the new kit in, back to the river. At first it did not want to pick up and go but after a couple of tries it began running fairly good. Max rpm still only 3800, but going 24mph (gps). I ran it down the river about a mile and seemed to be running fairly good.
I slowed to a stop and decided to change the tilt on the motor to see how it affected the speed. After tilting the motor up, making the adjustment and setting it back down the motor did not want to run again. Hard to start, seemed like a fuel problem still. I could cover the throttle inlet and get it to start, but it would not keep running. I finally put the moter tilt back at the original setting and succeeded in getting it to a rough idle. I was able to limp back to the dock at a 1000 rpm but could not accelerate above that. The idle was very rough. I am beginning to wonder about the coils or ???

I don't know what the tilt would have to do with it, but I had changed the tilt yesterday before problems started so I though I would mention it.

I am at a loss and my son is coming home Tuesday. Hoping to go fishing together.

any suggestions are appreciated.
Sorry for the long post.

25 hp Johnson (1996) 14' flatbottom. Carb kit put in last week. Fuel pump kit and spark plugs today.

Thanks,

RW

 

[Cofe]

Re: And then it died

Does pumping the bulb have any effect when it is acting up? If it does, you have a fuel delivery problem. Tank suction, Tank Vent, O-rings in the hose connections, kinked hose, loose hose fittings, dirty carb, Old fuel, water in the fuel.
Did you test your fuel pump after you installed the kit?

 

[levi_tsk]

Re: And then it died

carb float not adjusted right ? too much pitch on the prop?? too much pitch lugs the engine and causes all kinda problems -let it eat !!

 

[hidef]

Re: And then it died

What is the model number of the outboard? You could have multiple issues but without knowing the particulars of your outboard it makes it harder to help you trouble shoot the issue.

 

[thewaya]

Re: And then it died

I have had this problem with 2 motors in the past....
It could be several things...and I am no expert but Here is what I did..
The first was a bad fule problem...had cloged up my filter and carb jets had
to be cleaned out.
The second was a dirty carb...soaked the carb in cleaner. worked fine.
it still does it if I let it sit up for a length of time.
I get carb cleaner and spray it in the carb and the spark plug holes.
I then turn the motor over to eject the fluid out of the cylinders and put
back the spark plugs and start it..... may have to take the carb off and soak it.
try spraying in the carb cleaner while the motor is running...just enough to keep it running
dont stall it completely out....do this several times and if the rpm picks up you have a carb problem
Did you do a overnight soak on the carb when you put in the kit?

 

[Tim Frank]

Re: And then it died

When you put in the carb kit did you clean the HS jet as Cofe suggested?
Also, if there are welch plugs on that carb, did you pop them and clean in behind them?

 

[R Willis]

Re: And then it died

Thanks for the replies and help!

To all, the whole fuel system is new. Tank, hose w/filter, etc. I rebuilt the carb last week and it seemed to be running good on the test run. Then I installed a tach, went back out the check performance and evaluate prop, etc. On this run, after about 2 miles down the river, (max rpms 3800, 24mph) I stopped and shifted the tank, etc to evaluate weight distribution. When I started it back up was when the current problems began. It began running slower, lined out at 3200 rpm for a while then soon after dropped down to barely above idle, then quit. (see OP)
Got it home, next morning I rebuilt the fuel pump, I did find a check valve that was coming apart. Test run after rebuilding the fuel, it ran good for about a minute then died and restarted, this happened a couple of times, then it lined out and began run ok (only 3800 rpm), I went down the river a ways, stopped for a minute. Restarted and it began the same thing all over again. It would only run just above idle (1000 rpm). I limped back to the dock and went home.
After reading the replies I am wondering if some debris from the fuel pump check valve got into the carb. I will pull it tomorrow and do another clean and rebuild, checking for debris.

As far as the max rpm of 3800, I do have questions about the prop but will address that in another thread.

The model is J25TEEDA.

Thanks for the help, I will post updates.

RW

 

[boobie]

Re: And then it died

I believe on that mtr the tach should be set on 5 pulse.

 

[R Willis]

Re: And then it died- But Now it Lives!!!

Re: And then it died- But Now it Lives!!!

OK, just a follow up on this saga.

After all of the replies and reviewing the chain of events, Here is the simple version of the events.
Motor was only running about mid throttle (had been sitting a couple of years).
I cleaned the carb. No change.
I pulled the carb and installed a kit. It was better for a while then started stalling again, poor idle, no acceleraton, etc.
I rebuilt the fuel pump and discovered one of the check valves was coming apart.
Test run, it was good for a couple of miles, then the symptoms started again.
Began to suspect that debris from the check valve must have gotten into the rebuilt carb.
This morning, being pressed for time, I called the local boat shop and took it them to check the carburetor. They pulled it apart and found suspected debris. Cleaned it all out and put it back together. Test run, it ran really good!
Suspicion confirmed and remedied. All is good.
But now I do have some new questions but I will start a new threadl

Thanks to all for your help and suggestions.

RW