Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Joe
 
Posts: n/a
Default 1983 15 hp Johnson o/b that just won't run right!



The problem with the 15 hp is as follows.

I bought this motor two years ago from a guy who claimed to be selling it
for the wife of a deceased friend. He didn't have much info on the engine
except to say it had not been run in at least 5 years. (I willing to bet

it
was like 10 or more years.)

Although originally I could not get it started, I've now had it serviced

by
three different repair shops, all with OMC backgrounds. It's been
decarbonized, had the carburetor cleaned and rebuilt, new plugs and had
numerous other minor issues resolved. The water pump hasn't been

overhauled,
but the mechanics have all claimed that the impeller is fine as the engine
produces a sufficient "pee-stream." However, the big problem hasn't been
solved.


If its been sitting for that long I would replace the impeller ASAP.

When the engine hasn't been used overnight or for a few days, it starts on
the first or second pull and will idle OK. It will also run fine under

full
power on that first run and push our 14ft aluminum skiff at 20-25 miles an
hour. From that point the reliability goes downstream fast and has me

ready
to use it as an anchor.

The fun starts when the engine will not idle after being run at full or

half
throttle. It will also not restart easily if it is hot and/or has stalled
out. You can sometimes get it started if you override the neutral-start
interlock and immediately give more throttle than the "over-rev" limiter

in
neutral will allow. I know it's dangerous and for that reason won't let my
kids drive it. Letting it sit for a while, an hour or so, gives you a

better
shot of restarting it, but not reliably and/or keeping it running.

Ironically, when I've picked it up, all the shops have told me how great

it
runs in the test tank; they claim it starts right up, idles nicely and

runs
as well as can be expected for this age motor. I don't doubt that it does
(in their test tanks), but I think they're all missing something. On the
other hand, I'm sure they think I'm neurotic about this engine.

Any thoughts suggestions or insights would be greatly appreciated.

Bill Lav


Have you checked the fuel system for adequate venting?
If not vented properly a vacuum can develop in the tank causing the problem
you describe.
Next time it happens try removing the gas cap and check for a vacuum.


  #2   Report Post  
noah
 
Posts: n/a
Default 1983 15 hp Johnson o/b that just won't run right!

On Tue, 12 Aug 2003 02:27:34 GMT, "Bill Lavernoich"
wrote:

The problem with the 15 hp is as follows.

I bought this motor two years ago from a guy who claimed to be selling it
for the wife of a deceased friend. He didn't have much info on the engine
except to say it had not been run in at least 5 years. (I willing to bet it
was like 10 or more years.)

Although originally I could not get it started, I've now had it serviced by
three different repair shops, all with OMC backgrounds. It's been
decarbonized, had the carburetor cleaned and rebuilt, new plugs and had
numerous other minor issues resolved. The water pump hasn't been overhauled,
but the mechanics have all claimed that the impeller is fine as the engine
produces a sufficient "pee-stream." However, the big problem hasn't been
solved.

When the engine hasn't been used overnight or for a few days, it starts on
the first or second pull and will idle OK. It will also run fine under full
power on that first run and push our 14ft aluminum skiff at 20-25 miles an
hour. From that point the reliability goes downstream fast and has me ready
to use it as an anchor.

The fun starts when the engine will not idle after being run at full or half
throttle. It will also not restart easily if it is hot and/or has stalled
out. You can sometimes get it started if you override the neutral-start
interlock and immediately give more throttle than the "over-rev" limiter in
neutral will allow. I know it's dangerous and for that reason won't let my
kids drive it. Letting it sit for a while, an hour or so, gives you a better
shot of restarting it, but not reliably and/or keeping it running.

Ironically, when I've picked it up, all the shops have told me how great it
runs in the test tank; they claim it starts right up, idles nicely and runs
as well as can be expected for this age motor. I don't doubt that it does
(in their test tanks), but I think they're all missing something. On the
other hand, I'm sure they think I'm neurotic about this engine.

Any thoughts suggestions or insights would be greatly appreciated.

Bill Lav


Bill- I suspect that the engine shops haven't run this engine long
enough to heat it up. Time is money, ya' know? )

Your problems sound like they are heat related, which could be a coil
breaking down, condenser breaking down, etc. Call the last guy that
worked on it and ask if he guarantees his work. If not, move on, and
find a shop that will do it right.

FWIW, get the impellor replaced. If the old one is brittle and
cracked, it could "pee" at idle, and fail to move enough water at WOT.
It's also possible that there's a partial blockage in the water flow.

Finding a good boat mechanic is a lot like finding a good car
mechanic. You pays your dollar, and you takes your chances. I've
been 50% lucky, I've got a great boat mechanic.

Good luck,
noah

Courtesy of Lee Yeaton,
See the boats of rec.boats
www.TheBayGuide.com/rec.boats
  #3   Report Post  
Larry
 
Posts: n/a
Default 1983 15 hp Johnson o/b that just won't run right!

I'm leaning on a bad stator on this one. When they get hot, the
windings expand and if something's broken loose the spark sucks until
it gets cool again.

When it's cool and running fine, hook one plug wire up to an external
spark plug that's grounded to the block so you can see the spark.
Note how the spark looks.

Then, when it's running like crap, do that again and see if you don't
see a real thin, wimpy weak spark that compression can blow out the
fire to.....

I had a stator on an Evinrude 3-cyl 55 that worked great whenever a
mechanic was looking at it because, in his haste, he never got the
motor hot enough to make it fail....

Gets hot under that flywheel.....



On Tue, 12 Aug 2003 02:27:34 GMT, "Bill Lavernoich"
wrote:

The problem with the 15 hp is as follows.

I bought this motor two years ago from a guy who claimed to be selling it
for the wife of a deceased friend. He didn't have much info on the engine
except to say it had not been run in at least 5 years. (I willing to bet it
was like 10 or more years.)

Although originally I could not get it started, I've now had it serviced by
three different repair shops, all with OMC backgrounds. It's been
decarbonized, had the carburetor cleaned and rebuilt, new plugs and had
numerous other minor issues resolved. The water pump hasn't been overhauled,
but the mechanics have all claimed that the impeller is fine as the engine
produces a sufficient "pee-stream." However, the big problem hasn't been
solved.

When the engine hasn't been used overnight or for a few days, it starts on
the first or second pull and will idle OK. It will also run fine under full
power on that first run and push our 14ft aluminum skiff at 20-25 miles an
hour. From that point the reliability goes downstream fast and has me ready
to use it as an anchor.

The fun starts when the engine will not idle after being run at full or half
throttle. It will also not restart easily if it is hot and/or has stalled
out. You can sometimes get it started if you override the neutral-start
interlock and immediately give more throttle than the "over-rev" limiter in
neutral will allow. I know it's dangerous and for that reason won't let my
kids drive it. Letting it sit for a while, an hour or so, gives you a better
shot of restarting it, but not reliably and/or keeping it running.

Ironically, when I've picked it up, all the shops have told me how great it
runs in the test tank; they claim it starts right up, idles nicely and runs
as well as can be expected for this age motor. I don't doubt that it does
(in their test tanks), but I think they're all missing something. On the
other hand, I'm sure they think I'm neurotic about this engine.

Any thoughts suggestions or insights would be greatly appreciated.

Bill Lav



Larry

Extremely intelligent life must exist in the universe.
You can tell because they never tried to contact us.

  #4   Report Post  
Clams Canino
 
Posts: n/a
Default 1983 15 hp Johnson o/b that just won't run right!

Low speed winding to be specific. (assuming Jonnyrudes have one)

-W

"Larry" wrote in message
...
I'm leaning on a bad stator on this one. When they get hot, the
windings expand and if something's broken loose the spark sucks until
it gets cool again.

When it's cool and running fine, hook one plug wire up to an external
spark plug that's grounded to the block so you can see the spark.
Note how the spark looks.

Then, when it's running like crap, do that again and see if you don't
see a real thin, wimpy weak spark that compression can blow out the
fire to.....

I had a stator on an Evinrude 3-cyl 55 that worked great whenever a
mechanic was looking at it because, in his haste, he never got the
motor hot enough to make it fail....

Gets hot under that flywheel.....



On Tue, 12 Aug 2003 02:27:34 GMT, "Bill Lavernoich"
wrote:

The problem with the 15 hp is as follows.

I bought this motor two years ago from a guy who claimed to be selling it
for the wife of a deceased friend. He didn't have much info on the engine
except to say it had not been run in at least 5 years. (I willing to bet

it
was like 10 or more years.)

Although originally I could not get it started, I've now had it serviced

by
three different repair shops, all with OMC backgrounds. It's been
decarbonized, had the carburetor cleaned and rebuilt, new plugs and had
numerous other minor issues resolved. The water pump hasn't been

overhauled,
but the mechanics have all claimed that the impeller is fine as the

engine
produces a sufficient "pee-stream." However, the big problem hasn't been
solved.

When the engine hasn't been used overnight or for a few days, it starts

on
the first or second pull and will idle OK. It will also run fine under

full
power on that first run and push our 14ft aluminum skiff at 20-25 miles a

n
hour. From that point the reliability goes downstream fast and has me

ready
to use it as an anchor.

The fun starts when the engine will not idle after being run at full or

half
throttle. It will also not restart easily if it is hot and/or has stalled
out. You can sometimes get it started if you override the neutral-start
interlock and immediately give more throttle than the "over-rev" limiter

in
neutral will allow. I know it's dangerous and for that reason won't let

my
kids drive it. Letting it sit for a while, an hour or so, gives you a

better
shot of restarting it, but not reliably and/or keeping it running.

Ironically, when I've picked it up, all the shops have told me how great

it
runs in the test tank; they claim it starts right up, idles nicely and

runs
as well as can be expected for this age motor. I don't doubt that it does
(in their test tanks), but I think they're all missing something. On the
other hand, I'm sure they think I'm neurotic about this engine.

Any thoughts suggestions or insights would be greatly appreciated.

Bill Lav



Larry

Extremely intelligent life must exist in the universe.
You can tell because they never tried to contact us.



  #5   Report Post  
Bill Kiene
 
Posts: n/a
Default 1983 15 hp Johnson o/b that just won't run right!

Bill,

That is a good, very popular motor that they should be able to get running
well for you. It is less than 20 years old too. Don't give up on it yet.

--
Bill Kiene

Kiene's Fly Shop
Sacramento, CA
www.kiene.com

"Bill Lavernoich" wrote in message
gy.com...

Just a quick follow up to my initial post.

I stopped by the "third" guy's shop this afternoon. He claims that I

never
told him it was "hard starting after it had been run" and that it wouldn't
idle when hot. All his notes showed was that he wrote down "hard

starting"
when I dropped it off, which of course wasn't the case when he first

started
it. He's living proof that most people only listen to the first couple of
words and "assume" the rest.

Also, he apparently didn't do anything to the carburetor except change a
couple of gaskets and adjust the idle screw. He questioned the condition

of
the tank and gas, and whether I had properly vented it. Brand new plastic
OMC 3gal. tank and fresh gas and oil. This OMC tank doesn't have a
screw-vent on the cap. I also raised the "overheating Stator" issue, but

he
downplayed this as the most expensive part of the engine that "everybody
replaces" when they don't have to. Of course he also didn't look at the
water pump and impeller because he didn't think it was a problem. (Of
course, he was going to give it a complete going-over.)




Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Power lift retrofit for 48 HP Johnson? Rural Knight General 0 August 8th 03 07:30 PM
Help: 50 hp Johnson ('72) allergic to water DundasJim General 4 July 21st 03 02:25 AM
15 HP Johnson overheat Q Joe Here General 8 July 15th 03 03:11 AM
55 johnson for parts Bob General 1 July 11th 03 02:33 PM
Stiff steering on Johnson 15hp Lloyd Sumpter General 1 July 11th 03 12:22 AM


All times are GMT +1. The time now is 07:14 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 BoatBanter.com.
The comments are property of their posters.
 

About Us

"It's about Boats"

 

Copyright © 2017