Merc outboard questions
 

Took my Lund/Merc 40 4 cyl 2 cycle fishing the last two days. It cuts out
quite a bit, and I'm suspecting jetting. The gas is fresh. Plugs are new.

I need to buy a manual, but don't want to part with the $$$. I've done a
lot of carb adjustments on cars, motorcycles, atv's, etc.

This motor has two carbs. Are the low speed jets just brass screws that you
adjust at a high idle? Something was mentioned about high speed jets, and
do those need to be adjusted when the boat is going fast? Or is it a thing
of 1 1/2 turn from closed, or something like that?

The engine compartment is crowded on that motor, but I know I could pull the
cowling, and figure it out with a flashlight and some time.

Help would be appreciated, especially links to diagrams so I could pick out
the high and low, and other tips.

That is, when you're not busy talking politics. Politics is just too boring
and depressing, so I have decided that I want to go boating and fishing
instead, and at least if the end comes, I'll be standing in my boat for the
initial nuclear flash.

thanks.

Steve

Merc outboard questions
 

On May 3, 3:04*pm, "SteveB" wrote:
Took my Lund/Merc 40 4 cyl 2 cycle fishing the last two days. *It cuts out
quite a bit, and I'm suspecting jetting. *The gas is fresh. *Plugs are new.

I need to buy a manual, but don't want to part with the $$$. *I've done a
lot of carb adjustments on cars, motorcycles, atv's, etc.

This motor has two carbs. *Are the low speed jets just brass screws that you
adjust at a high idle? *Something was mentioned about high speed jets, and
do those need to be adjusted when the boat is going fast? *Or is it a thing
of 1 1/2 turn from closed, or something like that?

The engine compartment is crowded on that motor, but I know I could pull the
cowling, and figure it out with a flashlight and some time.

Help would be appreciated, especially links to diagrams so I could pick out
the high and low, and other tips.

That is, when you're not busy talking politics. *Politics is just too boring
and depressing, so I have decided that I want to go boating and fishing
instead, and at least if the end comes, I'll be standing in my boat for the
initial nuclear flash.

thanks.

Steve

Check out this iboats thread:

http://forums.iboats.com/showthread.php?t=170490

Steve, has the boat sat for quite a while. If so then the fresh gas is
good but the innards of the carb are probably corroded a bit. One
thing a person can do is to get some "Seafoam" and use it via the
directions.

http://carfood.com/noname34.html

it's used a lot on motorcycles, and snowmobiles etc. it's pretty good
stuff and it might cure the problem without having to take the carbs
off an have them soaked and rebuilt.

Merc outboard questions
 

"SteveB" wrote in message
...
Took my Lund/Merc 40 4 cyl 2 cycle fishing the last two days. It cuts out
quite a bit, and I'm suspecting jetting. The gas is fresh. Plugs are
new.

I need to buy a manual, but don't want to part with the $$$. I've done a
lot of carb adjustments on cars, motorcycles, atv's, etc.

This motor has two carbs. Are the low speed jets just brass screws that
you adjust at a high idle? Something was mentioned about high speed jets,
and do those need to be adjusted when the boat is going fast? Or is it a
thing of 1 1/2 turn from closed, or something like that?

The engine compartment is crowded on that motor, but I know I could pull
the cowling, and figure it out with a flashlight and some time.

Help would be appreciated, especially links to diagrams so I could pick
out the high and low, and other tips.

That is, when you're not busy talking politics. Politics is just too
boring and depressing, so I have decided that I want to go boating and
fishing instead, and at least if the end comes, I'll be standing in my
boat for the initial nuclear flash.

thanks.

Steve

I just got a manual for my Force (actually EVERY Force) on CD on ebay for 2
bucks and 3 for shipping. It's kind of a PITA not having a book but I can
print the pages I need.
Also, related to Tims post, didn't you clean the bowls and jets? I
remembered that discussion from a few weeks ago with someone. If not, you'll
find a bunch of gunk from the old gas evaporating.

Merc outboard questions
 

wrote in message
...
On Sun, 3 May 2009 14:04:53 -0600, "SteveB"
wrote:

Took my Lund/Merc 40 4 cyl 2 cycle fishing the last two days. It cuts out
quite a bit, and I'm suspecting jetting. The gas is fresh. Plugs are
new.

I need to buy a manual, but don't want to part with the $$$. I've done a
lot of carb adjustments on cars, motorcycles, atv's, etc.

This motor has two carbs. Are the low speed jets just brass screws that
you
adjust at a high idle? Something was mentioned about high speed jets, and
do those need to be adjusted when the boat is going fast? Or is it a
thing
of 1 1/2 turn from closed, or something like that?


The idle jets are adjusted similar to your old cars.
Run then in tight and back them out 1 1/4 - 1 12 turns for a starting
point. That only affects the idle. The high speed jets are fixed.

I doubt this will fix anything.

What do you mean "cutting out?"

If this is a gradual cutting in and out I would still be looking at
fuel but if it is abrupt you could have an ignition problem. Can you
figure out if this is just one cylinder?

The "cutting out" is mainly I feel that it does not attain highest rpms
possible. It does not spit or sputter at high speed, but does it quite a
bit at low between idle and about 5 mph.

I did not really dig into the engine yet. I completely rebuilt an Evinrude
60 that sucked a stainless washer into a cylinder, so think I could just
disassemble and check float bowls, etc, and fiddle with the low speed jets
in a tank of water. I kinda figured the 1.5 turn thing, as that seems to be
standard, tho not for all. My ATV is 1 1/8 turn. go figger. I will
eventually take this to a real mechanic at a shop, but I just hate paying
big bucks for small simple fixes that I can do.

Until then, there's a list of things I need to work on in the boat, as is
common with all boats. For now, it runs okay, just that low speed stalling
problem that's aggravating.

Thanks for the help.

Steve

Merc outboard questions
 

"SteveB" wrote in message
...
Took my Lund/Merc 40 4 cyl 2 cycle fishing the last two days. It cuts out
quite a bit, and I'm suspecting jetting. The gas is fresh. Plugs are
new.

I need to buy a manual, but don't want to part with the $$$. I've done a
lot of carb adjustments on cars, motorcycles, atv's, etc.

This motor has two carbs. Are the low speed jets just brass screws that
you adjust at a high idle? Something was mentioned about high speed jets,
and do those need to be adjusted when the boat is going fast? Or is it a
thing of 1 1/2 turn from closed, or something like that?

The engine compartment is crowded on that motor, but I know I could pull
the cowling, and figure it out with a flashlight and some time.

Help would be appreciated, especially links to diagrams so I could pick
out the high and low, and other tips.

That is, when you're not busy talking politics. Politics is just too
boring and depressing, so I have decided that I want to go boating and
fishing instead, and at least if the end comes, I'll be standing in my
boat for the initial nuclear flash.

thanks.

Steve
Our local library system has manuals for various outboards, outboard
families, cars, and motorcycles. Have you tried looking there. The local
system's catalog is on line making a quick check easy. Yours may be as well.

Merc outboard questions
 

"tak" wrote

Our local library system has manuals for various outboards, outboard
families, cars, and motorcycles. Have you tried looking there. The local
system's catalog is on line making a quick check easy. Yours may be as
well.

Dang. Thanks. I would have never thought of that.

Steve