Folks....

I have a 15 HP Johnson model J15RENM outboard motor (rope start) and a
25 HP Mariner model 25ELH outboard motor (electric start). Both are 2
cycle engines where you mix the oil with the gas.

Neither motor has run for about 2 years now. Before the long set,
they ran sweet. I took them both out last week, and I now have to run
the 25 HP Mariner at full throttle, and the 15HP Johnson at half
throttle.

The Mariner runs sweet at full choke, but I don't want it that way. I
never used to have it choked at all (except briefly to start it). The
Johnson runs good at half throttle, but then wants to stall once in a
while. As soon as the motor labors and sounds like it's dying, I pull
the choke out a little more. Sometimes I can save it, and sometimes
it stalls. One pull of the rope though is all it takes to start it
again.

Both seem to be starving for fuel, and I'm assuming that it is some
varnish buildup. They ran so good before the 2 year period, that I'm
pretty certain there is nothing mechanical going on. I am going to be
running some SeaFoam through the fuel system this weekend. I've
already run a little through the system, but it hasn't showed signs of
helping yet. I know I have to give that a little more time though.

What I'd like to get is a scan from a manual on either (or both) of
these two motors as to exactly where the fuel filter is, and also how
to get to the carburetor jets. Even a digital picture from a camera
would work for me if someone would happen to have one of these models,
and might happen to have it apart. I'd just like to know where they
are and what they look like before I tear into anything.

Thanks..... Mac

You chances are slim that someone has a picture. You could try to buy a
service manual. My experience with most small engines is that he carb is
pretty straight forward. The main jet is going to be immersed in the fuel
bowl if it has one. If not it is still usually pretty obvious. You should
disassemble and clean the entire carb. The idle circuit and any other
compensation circuits are more likely to be gummed up that the main anyway.
The fact that one of them runs at full throttle suggests that as well. At
full throttle it's the main jet you are running on. Lack of idle suggest
the idle circuit. Look for a rebuild kit online or locally as you'll want
to replace the various gaskets and o-rings. Make sure you spray carb
cleaner and if you have it, compressed air through all the small fuel
passages.

wrote in message
ups.com...
Folks....

I have a 15 HP Johnson model J15RENM outboard motor (rope start) and a
25 HP Mariner model 25ELH outboard motor (electric start). Both are 2
cycle engines where you mix the oil with the gas.

Neither motor has run for about 2 years now. Before the long set,
they ran sweet. I took them both out last week, and I now have to run
the 25 HP Mariner at full throttle, and the 15HP Johnson at half
throttle.

The Mariner runs sweet at full choke, but I don't want it that way. I
never used to have it choked at all (except briefly to start it). The
Johnson runs good at half throttle, but then wants to stall once in a
while. As soon as the motor labors and sounds like it's dying, I pull
the choke out a little more. Sometimes I can save it, and sometimes
it stalls. One pull of the rope though is all it takes to start it
again.

Both seem to be starving for fuel, and I'm assuming that it is some
varnish buildup. They ran so good before the 2 year period, that I'm
pretty certain there is nothing mechanical going on. I am going to be
running some SeaFoam through the fuel system this weekend. I've
already run a little through the system, but it hasn't showed signs of
helping yet. I know I have to give that a little more time though.

What I'd like to get is a scan from a manual on either (or both) of
these two motors as to exactly where the fuel filter is, and also how
to get to the carburetor jets. Even a digital picture from a camera
would work for me if someone would happen to have one of these models,
and might happen to have it apart. I'd just like to know where they
are and what they look like before I tear into anything.

Thanks..... Mac

On Wed, 18 Jul 2007 23:23:40 -0000, wrote:

Folks....

I have a 15 HP Johnson model J15RENM outboard motor (rope start) and a
25 HP Mariner model 25ELH outboard motor (electric start). Both are 2
cycle engines where you mix the oil with the gas.

Here's a blow-up of the Johnson carb:
http://www.crowleymarine.com/brp_par...rams/38195.cfm

I didn't google further, but using model/serial numbers you can
sometime find info. Sometimes you're just better off buying a manual
if you think it's worth it.
One time an IDE controller went out on a daughters computer
motherboard. It was a Compaq Presario something or other, and
a new MB was @400 bucks. I spent a few hours reading through google
results on a number and found a 2 exchange discussion on some obscure
tech board where one of the techs said to another something like "That
Compaq Presario board is no different than the Acme 105 except for the
Compaq logo in the bios." So I bought an Acme 105 for 96 bucks and
all was well. But you have to have tolerance for that kind of
searching.

--Vic

On Jul 19, 8:16 am, Vic Smith wrote:
On Wed, 18 Jul 2007 23:23:40 -0000, wrote:
Folks....

I have a 15 HP Johnson model J15RENM outboard motor (rope start) and a
25 HP Mariner model 25ELH outboard motor (electric start). Both are 2
cycle engines where you mix the oil with the gas.

Here's a blow-up of the Johnson carb:http://www.crowleymarine.com/brp_par...rams/38195.cfm

I didn't google further, but using model/serial numbers you can
sometime find info. Sometimes you're just better off buying a manual
if you think it's worth it.
One time an IDE controller went out on a daughters computer
motherboard. It was a Compaq Presario something or other, and
a new MB was @400 bucks. I spent a few hours reading through google
results on a number and found a 2 exchange discussion on some obscure
tech board where one of the techs said to another something like "That
Compaq Presario board is no different than the Acme 105 except for the
Compaq logo in the bios." So I bought an Acme 105 for 96 bucks and
all was well. But you have to have tolerance for that kind of
searching.

--Vic

Looks like they want $38 for a kit. Kinda steep. It's "marine" :-)
Kit for a similar carb on a mower would be $14. You could disassemble
first being real careful and see if you can get by with the old
parts. That's what I usually do. It should be obvious when you tear
it down if you are going to have to buy the kit or not. Not sure what
the needle valve is but I'd pay close attention to that while
cleaning. Another good reason to get a service manual as you're going
to have to adjust that when you put it back on.

On Thu, 19 Jul 2007 11:50:39 -0700, jamesgangnc
wrote:


Looks like they want $38 for a kit. Kinda steep. It's "marine" :-)
Kit for a similar carb on a mower would be $14. You could disassemble
first being real careful and see if you can get by with the old
parts. That's what I usually do. It should be obvious when you tear
it down if you are going to have to buy the kit or not. Not sure what
the needle valve is but I'd pay close attention to that while
cleaning. Another good reason to get a service manual as you're going
to have to adjust that when you put it back on.

Speaking auto only, since I never worked on an OB, everything "carb"
seems to be getting really expensive. I put a few float kits and
needle valves in carbs, but always heard they must be chemical bathed
to clean passages. Had a 67 Skylark carb screwing up and it only cost
me $25 for the 2-barrel Carter reman and 5 minutes to do the swap.
Next time I entertained the carb replace idea was after doing the
heads on my van's 350. Hey, why not throw on a carb (4-barrel)
while I'm in here? Then I priced it. @400 bucks. Kept the old carb.
For a number of reasons, I *really* like FI.

--Vic