15 hp engine

F
fishtales
My engine sputters then stalls when in drive at the lowest speed. I have to give it has in order to keep it from stalling. But if it is in nutral I can keep it at the same low setting and it won't stall out on me. Has anyone else seen this?
 
O
OnTheFly
fishtales said:
My engine sputters then stalls when in drive at the lowest speed. I have to give it has in order to keep it from stalling. But if it is in nutral I can keep it at the same low setting and it won't stall out on me. Has anyone else seen this?

Sounds like not enough idle to keep the motor going under load. As you already know, as soon as gears, shaft, and prop come into play, it will slow the engine down and if the idle's not up it could stall. I had a boat that did this and it gets really frustrating. Hope this helps. :)
 
F
fishtales
Thanks. I have a call in to a guy who will take a look at it, but its going to cost 75 bucks an hour and he already said it would be about an hour and a half. It is a 4 year old mercury short shaft. Is there an easy way to look to see if it is the idle
 
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OnTheFly
fishtales said:
Thanks. I have a call in to a guy who will take a look at it, but its going to cost 75 bucks an hour and he already said it would be about an hour and a half. It is a 4 year old mercury short shaft. Is there an easy way to look to see if it is the idle

Idle or throttle adjustment should be easy to find. Another thing that could be happening is something may be wound inside the prop shaft area that is restricting rotation. A piece of rope once wound itself around the prop shaft of my father-in-laws boat and the motor would instantly stall when put into gear. We removed the prop and cleaned out all the rope and it ran fine. Perhaps send Irishrover a message. He's got twin Merc's on his boat and I'm sure he can give you more ideas.
 
T
Thuggin4Life
For sure its the idle my little six horse did the same thing.
 
F
fishtales
I might try see if there is something caught in the shaft and while doing so attempt to locate where i can adjust the idle. It is a start. Thanks
 
S
SNDSLGR
Low idle probly due to a partialy plugged pilot jet. Adjust your idle and if that dont help clean the carb thuroughly.
 
O
Osprey
Have you tried running some SEAFOAM through it? Good stuff...it works wonders!
 
F
fishtales
I'm not real familiar with sea foam. I was going to use it in my car when I accidentally let it run out of oil. When I asked around the service tech I talked to said that the engine was still too new for it and that using sea foam may cause damage. At some point it might be a good idea especially if there is build up
 
E
ecarpet1
It should be really easy to adjust the idle on your motor. I think about the only adjusment screw left on most of the carbs is the idle adjust.

I run old motors that eat lots of gas but are easy to adjust the carbs.
 
M
Mike123
Adjust the air fuel screws..

There should be a wide open one and an idle one.
With it wide open turn them until it wants to die, then turn the other way till it wants to die, then find the middle of the two where it runs the best.

Do the same at idle with the idle adjustment.
 
G
GDBrown
Low speed stall

Low speed stall

fishtales said:
My engine sputters then stalls when in drive at the lowest speed. I have to give it has in order to keep it from stalling. But if it is in nutral I can keep it at the same low setting and it won't stall out on me. Has anyone else seen this?

I had a simmilar problem that I finally traced to a plugged low speed exhaust port. When the engine is at idle there is not enough exhaust pressure to push the water out of the lower unit and is allowed to escape from a small exhaust port at the rear of the engine above the water line. It drove me nuts for a whole season before I accidently found it while cleaning. It is not shown in any diagram that I could find and the guy at Steven's marine confirmed that the port plugging will cause stalling. I used a small hex tool(1/8 in) to clean it and never had a problem after cleanning.

Hope this is helpful,

GD
 
F
fishtales
I will see if I can find that hole and clear it up. It works it just stugles. It is in storage but an going to pick it up tomorrow after my class.
 
F
fishtales
Well I decided to bring it in and have it looked at. From what the mechanic indicated it is the carburetor. So you guys were right. I need to figure out how to work on theses things.

The good news is that it will be running the way it was intended to run. I am also looking to upgrade the boat to something a little bit longer and deeper with steering. Most of the time I am fishing on a lake or taking it in the bay for crab.

With the current boat there is always a chance we might drown so from now till about February I'm going to be looking for a boat. In the mean time thanks for the help and I will keep posting.
 
L
livin2fish
fishtales said:
I'm not real familiar with sea foam. I was going to use it in my car when I accidentally let it run out of oil. When I asked around the service tech I talked to said that the engine was still too new for it and that using sea foam may cause damage. At some point it might be a good idea especially if there is build up

hey fishtales did you get your engine problem fixed?
 
F
fishtales
Well it is finally done. They cleaned the carb and suggested running the engine till it is empty everytime we take it out. So I will need to disconect the fuel line every time. They also fixed a pigging noise by making an ajustment on the engine cover. The ping would only happen when the engine ran at full speed. Anyhow I am very thankful for all the help.

Once I get it home I think I will fill up the garbage with water and stick it in to give it a test run before taking it out to a river or lake.
 

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