1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

[mfay1971]

Hi Everyone,

I hope one of you can help...extremely frustrating issue with my Johnson/Evinrude ob motor.

Here is the deal:

Engine has run perfect for the last 7-8 months, and is very well maintained.
Yesterday (after an entire day of perfect use) on the way back in, the motor started sputtering and bogging down. It happens at full bore, and just putting along.

Seemed like a fuel issue to me, so I focused on that. This morning I got up, pulled the carb and performed the following:
- Cleaned entire carb
- Replaced float
- Replaced ALL fuel lines, including external (from tank/water separator filter) and internal (inside the engine cover)
- Replaced fuel line bulb
- Replaced all external fuel connectors, including both on the line, and on the tanks
- Replaced external water separator filter
- Pulled the fuel pump and cleaned completely, this included disassembling the fuel filter and cleaning the entire unit, including replacing all fuel lines...as noted above
- Replaced both spark plugs

After performing the above service, I took the boat out, it ran perfect for 10-15 mins...and then the SAME THING happened again. Rough running, bogging down, until finally stalling out. Got back in with my electric trolling motor.

Notes:
- Fuel pump is only 8 months old
- Plugs were only 8 months old
- I rebuilt the carb 8 months ago (full rebuild kit)
- Spark plug wires are a few years old, and were not replaced 8 months ago

I know it's 3 days before Christmas, but I have several family members here for the holiday hoping to do some SouthWest Florida fly fishing for the holidays.

Thanks everyone! Any input is appreciated!

 

[alldodge]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Hi Everyone,

I hope one of you can help...extremely frustrating issue with my Johnson/Evinrude ob motor.

Here is the deal:

Engine has run perfect for the last 7-8 months, and is very well maintained.
Yesterday (after an entire day of perfect use) on the way back in, the motor started sputtering and bogging down. It happens at full bore, and just putting along.

Seemed like a fuel issue to me, so I focused on that. This morning I got up, pulled the carb and performed the following:
- Cleaned entire carb
- Replaced float
- Replaced ALL fuel lines, including external (from tank/water separator filter) and internal (inside the engine cover)
- Replaced fuel line bulb
- Replaced all external fuel connectors, including both on the line, and on the tanks
- Replaced external water separator filter
- Pulled the internal fuel filter (inside the engine cover) and cleaned completely, this included disassembling the fuel filter and cleaning the entire unit, including replacing all fuel lines...as noted above
- Replaced both spark plugs

After performing the above service, I took the boat out, it ran perfect for 10-15 mins...and then the SAME THING happened again. Rough running, bogging down, until finally stalling out. Got back in with my electric trolling motor.

Notes:
- Fuel pump is only 8 months old
- Plugs were only 8 months old
- I rebuilt the carb 8 months ago (full rebuild kit)
- Spark plug wires are a few years old, and were not replaced 8 months ago

I know it's 3 days before Christmas, but I have several family members here for the holiday hoping to do some SouthWest Florida fly fishing for the holidays.

Thanks everyone! Any input is appreciated!

Sounds like a fuel issue to me as well. Since it runs great and then starts dying after a given amount of time. Try running an when it starts remove the cap off the gas tank and see if it picks back up. If it does the vent isn't working and your drawing a vacuum.

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Dodge,

Thanks for the comment...and I did try that. My tanks have the screw vent on the tops of them...didn't help. :grumpy:

 

[Boatdoc58]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Are you sure it isn't overheating ?

 

[alldodge]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Dodge,

Thanks for the comment...and I did try that. My tanks have the screw vent on the tops of them...didn't help. :grumpy:

Then the next thought is fuel pump. I know you said the pump is 8 months but look here and see if the test shows anything.
Boatinfo - 1971-1989 Evinrude Service manual

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Thanks Dodge, looking now, and will post back after I look.

Boatdoc, how can I tell if it is overheating? I can tell you the water pump is new (7-8 months), and seems to be working fine with a steady stream of output.

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Ok all, here is the update:

Dodge, I tried the fuel pump test, but it tested ok. Either way, I replaced the fuel pump with a brand new one this morning. I also replaced a secondary fuel line that looked a little worn...Back below the carb (not attached to carb), and runs back connecting above the fuel pump. Looked good, but replaced it anyways...since I replaced all the others.

I set the boat in the water, ran it for 20 minutes, and and ran PERFECT. At about 21-22 mins, it crapped out again. Started sputtering...choking, etc. until it died. Had to use my trolling motor to get in again.

I am at a loss. I have either cleaned, replaced or rebuilt everything noted above in this thread. The only thing I have not replaced are the spark plug wires. Does this sound like something that would be caused by bad wires? Runs perfect, to die 20-25 mins after running?

Ugh...soooo frustrating. Any advice greatly appreciated.

 

[alldodge]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Starting to look more like something is either getting hot and breaking down or it's over heating. When it dies do you know if it is getting spark? I think your engine should have a vacuum cut out switch used to keep the engine from a runaway. If it goes bad you won't get spark but it usually works or doesn't, but since it is vacuum actuated heat could also effect it

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Dodge, thanks for the reply.

In terms of the spark, not sure if it gets spark when it dies...I can tell you that the output water while running is very warm, but not hot. I can keep my hand in it for as long as I want to.

Also, I am not sure about the vacuum cut out switch. I can research and see if that may be the issue. Stay tuned...

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Dodge, I researched my engine, and my year/HP size did not come with the vacuum cut-out switch. From what I can find, that was a feature on the 40hp in the 70's.

I'm starting to wonder if it's something with the ignition system/wiring/points after it warms up? I know you and boatdoc mentioned overheating, but I am not sure how to check that...other than feel test with the discharged water? Not sure how to check for spark when it dies either...any advice on how to check either?

 

[alldodge]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Dodge, I researched my engine, and my year/HP size did not come with the vacuum cut-out switch. From what I can find, that was a feature on the 40hp in the 70's.

I'm starting to wonder if it's something with the ignition system/wiring/points after it warms up? I know you and boatdoc mentioned overheating, but I am not sure how to check that...other than feel test with the discharged water? Not sure how to check for spark when it dies either...any advice on how to check either?

Get an infared temp gauge and check with the cowling off to measure heat. You could use your hand, but need to find out if your loosing spark or fuel. Have to wait for it to die and check to see which is missing.

 

[Bosunsmate]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

If you cant keep your hand on the heads its overheating.
Take a spark tester out with you

 

[jasper60103]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Would like to hear how this one works out.
Please keep us posted.

 

[w2much]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Sounds like power pack failure as it gets warm. You need to check the spark, especially when it quits.

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Update...took the boat out and ran it until the issue occurred. Ran great again, flying along for about 20 mins, then motor started surging, running rough, bogging...and then quit. Hooked up my timing light, cranked the engine...and had spark on both plugs.

Starting to think this is an overheating issue...but I replaced the water pump in May, and it's peeing like crazy. Water is very warm, but not hot. Can hold my hand under it for as long as I want to.

 

[AlTn]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

the water discharge you are referring to: is this the water pump indicator discharge water < pee stream >,or the water discharge from the exhaust relief holes <sputtering from the exhaust relief holes in the exhaust housing>?

 

[jasper60103]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Interesting. Seems like you covered fuel, spark and cooling, and I doubt compression is a issue as it ran great for 20 minutes.
One thought comes to mind though. I wonder if that wasted fuel being recycled back through the motor is the culprit? But I recall F_R mentioning this only affects the idle. I don't want to waste your time though. Hopefully someone chimes in with the answer.

The good news is at least you're getting stranded in Florida waters rather than Idaho. That would'nt be fun this time of year.
Hang in there.

jasper

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

AITn, water is flowing great from both the pee stream and the exhaust relief.

Jasper, great point! It's about 15 degrees in Idaho today!

Also, update on the boat: I have decided that whatever the issue is, it is beyond my pay-grade...the boat is now at the mechanic's shop.

I figure that he has better tools, he knows the boat well already (he is my regular mechanic), and can probably get me back on the water a lot faster than I can.

I'll post back after he diagnosis the problem. Either way, thanks for everyone's help and comments!

 

[jasper60103]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Yea, I'm curious to know what he finds. Thanks for the updates.

 

[mfay1971]

Re: 1983 25HP Johnson/Evinrude OB Bogs Down/Runs Rough/Stalls After Warming Up

Update from mechanic:

Issue is the stator assembly and ignition coil.

As an added bonus, he also found a leaky crankshaft seal we are replacing too. All in all, not bad. Parts were $71, including shipping. Around $75-$100 labor.

If shipping is speedy, I could be fishing with my new 9wt saltwater flyrod by the weekend.

Again, thanks everyone for the help...and I hope this post will assist anyone else with the same issue in the future.