dying out Merc 2 stroke

[Wilsonriverfisher]

1996 merc 25hp 2 stroke it dies at idle with throttle knob turned down. Is the primer bulb suppose to stay hard? Also noticed after letting it idle low it would die going into gear unless i do it quick. It is new to me motor and it looks like the plugs are worn. I also noticed with the cover off and running at idle the fuel filter does NOT stay full it slowly lowers. Any ideas would be great I have a Manual.

Thanks
M

 

[Wilsonriverfisher]

Re: dying out Merc 2 stroke

Whats the deal do I need to know a secret hand shake now? Is something I said worded improperly?

 

[rndn]

Re: dying out Merc 2 stroke

Patience. This is a great forum and as soon as one of the many experts, not me, have a chance, they will chime in.

 

[yorkserv]

Re: dying out Merc 2 stroke

I am not a specialist in this but these are things that I have read and I have experienced.

Yes the primer bulb should be i dont know if hard is the right word to use but more like full but soft as the motor is off. It seems as if you have an air leak in one of your fuel lines and you are getting just enough fuel while the engine is sitting at idle but when you place a load on it starves the engine out. It is something that you may want to inspect the entire fuel line you can be running the motor lean and will cause internal damages.

Second thing to check is if you have a adapter connection from fuel line into engine that could be causing a restriction i read in one thread to remove the adapter and feed fuel line straight in.

Last maybe carbs need cleaning could have tarnish some where in the carb not allowing the bowl to fill up. Try pumping the primer bulb while running the engine and have some one shift the motor into gear to see if you have the same problem

Also one thing that i read is pump primer bulb to see if you get gas coming out of carb vent to assure you are getting fuel into the carb

Once again just things i have learned through reading alot of these threads and to get you started till some one with more knowledge can assist you good luck.

 

[Robj]

Re: dying out Merc 2 stroke

Yes the primer bulb should stay hard and full of fuel when the engine is running. If it is not, you fuel pump needs a rebuild. Try running it while pumping the fuel primer, it should stay running.

Regarding your idle, how many rpm's at idle? Could be too low or it is time for a carb rebuild. I would first fix the fuel pump and then see how that works out.

If plugs look worn, time to buy new ones, they are cheap.

Have a great day,

Rob.

 

[Silvertip]

Re: dying out Merc 2 stroke

No! The primer bulb will NOT stay hard once the engine is running. Remember, fuel is being sucked through it, not forced through it. What it should NOT do is be sucked flat. It is also perfectly normal for a fuel filter to have a void in it. It all depends on the orientation of the filter. If it is installed perfectly vertical it will likely have no void. Horizontal or tilted a little will cause a void. No harm in that. If the plugs are suspect, replace them -- they are cheap and quickly eliminates a potential problem. A compression check is always a good idea when dealing with running issues. All the tinkering in the world will not make an engine run decent if it has low compression. If you have no idea when the carb was cleaned, rebuild it. On the other hand, the idle speed adjustment may simply be set to slow.