1999 40 hp 2 stroke starts wide open

[987654sundance]

I have a 1999 Mercury 40 hp 2 stroke. When I start it, no matter where the throttle is, it wants to start wide open. I have to shut it down right away. Then sometimes I have to move the throttle around just to get it to start. I need your help??? Thank You

 

[carholme]

Re: 1999 40 hp 2 stroke starts wide open

What is your engine s/n?

Is this a tiller or remote?

Gerry

 

[987654sundance]

Re: 1999 40 hp 2 stroke starts wide open

What is your engine s/n?

Is this a tiller or remote?

Gerry

Hi Gerry, It's a remote, 3 cylinder, very low hours. Serial number OG862225 An elderly couple owed it on a pontoon boat and it sat for 4 years. I had to replace the stator, trigger, and voltage regulator because a magnet broke free from the flywheel. The carburetors needed to be cleaned along with the fuel tank. The fuel filter, plugs, water pump, lower unit oil and seals were all changed. When I start the motor it runs wide open so I have to shut it down, the throttle does not control the fuel at all, but it moves all the linkages. I also think there's a problem with the safety shut off switch because it turns over when it feel like when I turn the key.

 

[boatwerx]

Re: 1999 40 hp 2 stroke starts wide open

Hi Gerry, It's a remote, 3 cylinder, very low hours. Serial number OG862225 An elderly couple owed it on a pontoon boat and it sat for 4 years. I had to replace the stator, trigger, and voltage regulator because a magnet broke free from the flywheel. The carburetors needed to be cleaned along with the fuel tank. The fuel filter, plugs, water pump, lower unit oil and seals were all changed. When I start the motor it runs wide open so I have to shut it down, the throttle does not control the fuel at all, but it moves all the linkages. I also think there's a problem with the safety shut off switch because it turns over when it feel like when I turn the key.

Wow sounds pretty dangerous. Sounds like you may have a serious timing advance problem with stator and trigger linkage. And or a huge vacuum leak like no gaskets under the carbs perhaps or someone rebuilt the carbs faulty. Also a fuel leak direct into the intake from fuel pump can cause same issue. A proper and safe diagnostics of steps need to be taken before you or the engine gets hurt. I would start by squeezing the fuel ball and make sure theres good back pressure with no signs of leaks into the engine and or ball getting soft while holding pressure on it. If any of those things happen I would stop immediately and determine fuel leakage. Visually inspect the intake and carb gasket area for correctly placed and patterned gaskets. Also refer to a manual for proper engine timing if those items have been replaced?

 

[mikey7453]

Re: 1999 40 hp 2 stroke starts wide open

@gerry I don't know the answers to those right off the s/n I will hafta get ... How do I tell between the the other like I said I am new to the 2 cycle out board and don't know much but have a 1974 400hp jet boat just tring to get my own fishing rig going.... Whats up with other reply on this post do you know? New to this site too
Thanks in advance for any help or info you can give me

Mike

 

[carholme]

Re: 1999 40 hp 2 stroke starts wide open

987654sundance;

Your s/n comes up as:

MERCURY - ( 40 H.P. (1999 ))
Serial No: 0G862225 Model No: 1043412VN

Parts list for model 1043412VN:

40/50 JET 30 (3 CYLINDER) 2-STROKE - Mercury, Mercruiser, Force, etc. Parts Lookup

The service manual you require is 90-852572. If you do not have this manual, see my message to you in Notifications at the top of this page.

When you say that all the linkages move, have you actually verified that the trigger arm is connected and moves the trigger freely?

I am not too sure I understand your last comment.

Gerry

 

[carholme]

Re: 1999 40 hp 2 stroke starts wide open

Mike:

It is not good to hi jack a posting by another member as it confuses everything with two or more problems in one thread. You are better off to create a new post of your own so someone can deal directly with your problem.

Gerry

 

[mikey7453]

Re: 1999 40 hp 2 stroke starts wide open

Guess I didn't know I posted on someone else thread Gerry .... Sorry about that I am new to this site and didn't notice I done that ... I will try this again in a new thread

 

[987654sundance]

Re: 1999 40 hp 2 stroke starts wide open

Wow sounds pretty dangerous. Sounds like you may have a serious timing advance problem with stator and trigger linkage. And or a huge vacuum leak like no gaskets under the carbs perhaps or someone rebuilt the carbs faulty. Also a fuel leak direct into the intake from fuel pump can cause same issue. A proper and safe diagnostics of steps need to be taken before you or the engine gets hurt. I would start by squeezing the fuel ball and make sure theres good back pressure with no signs of leaks into the engine and or ball getting soft while holding pressure on it. If any of those things happen I would stop immediately and determine fuel leakage. Visually inspect the intake and carb gasket area for correctly placed and patterned gaskets. Also refer to a manual for proper engine timing if those items have been replaced?

Hi Gerry, I checked the carburetors and the gaskets are all in place. I did squeeze the priming ball and it did get soft and there was no visible fuel leaking externally. The fuel linkage all seams to be moving properly. I will have to check tomorrow when I may have more time. Thank you for your time and patience!