Mercury 40Hp Lightning Xr

[joshagius]

hey all just wondering if anyone has owned a mercury 40hp lightning xr 2 stroke and has had a problem with the engine were it decelerates in speed without toching the throdle and then splutters down and stops running ? i have heard of afew people owning this engine and have had similar problems i was wondering if anyone was able diagnose there problem with it i have taken it to a marine mechanic but the problem didnt occour when they did a service but often happens to me when i go out for a fish !

[deek]

Hi joshagius,

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Cheers

Deek

[ron.c]

sounds like it is starving for fuel. did you open the vent on the tank.

[a boat]

Hi, we have sold many of these engines over the years and have not seen any more or less problems than all the other brands that come thru here. As mentioned if it a slow decrease it most liekly will be fuel related and the easiest things to check at home are the boats fuel supply and fit a new primer bulb. How old is it, has the carbies ever been serviced and also the fuel pump.

Cheers,

Huey.

[fishon]

also check all the joins on the fuel line are all tight i had the similar problem it was surging when

i got to WOT

changing and making sure every 1 was super tight fixed this problem

[rickb]

hey all just wondering if anyone has owned a mercury 40hp lightning xr 2 stroke and has had a problem with the engine were it decelerates in speed without toching the throdle and then splutters down and stops running ? i have heard of afew people owning this engine and have had similar problems i was wondering if anyone was able diagnose there problem with it i have taken it to a marine mechanic but the problem didnt occour when they did a service but often happens to me when i go out for a fish !

G/Day Josh, I had one of those little beauties years ago.

Fantastic motor, The only prob's I had was what you are having

all it took was replacing the primer bulb,some times I forgot to

open breather.

Mate last time we spoke did I tell you how to make a maltese

cross with two matches.

Cheers Rick.

[Browny76]

On 17/09/2010 at 8:26 AM, joshagius said:

hey all just wondering if anyone has owned a mercury 40hp lightning xr 2 stroke and has had a problem with the engine were it decelerates in speed without toching the throdle and then splutters down and stops running ? i have heard of afew people owning this engine and have had similar problems i was wondering if anyone was able diagnose there problem with it i have taken it to a marine mechanic but the problem didnt occour when they did a service but often happens to me when i go out for a fish !

Did you end up fixing the problem? Mines doing the same, when it starts to bog down I pump the primer and away she goes. So I'm assuming fuel problem maybe stemming from the fuel tank side. Let me know how you went!!

[will_l]

On 10/24/2016 at 9:59 AM, Browny76 said:

Did you end up fixing the problem? Mines doing the same, when it starts to bog down I pump the primer and away she goes. So I'm assuming fuel problem maybe stemming from the fuel tank side. Let me know how you went!!

Mate I had this issue with my last boat that had a 40 lightning XR, its fuel. The fuel line was old and had a lot of gunk in it. Just bought a new one for $20 and it ran perfectly.

 

[jeffb5.8]

I had similar problem with a 2007 25hp Mercury, Mine was the fuel bulb had started to collapse and partially block the fuel hose, under full revs it would cause the bulb to start to internally collapse even more until the point it stopped, the outside of the bulb looked fine but was hard as a rock.

Changed fuel line and it was all fixed, until the plastic fuel tank internal pick up hose played up, swapped to my spare metal tank and all fixed again.

[Browny76]

Thanks guys this sounds like what I need to try. The fuel looks old and I did notice the bulb collapsing.