Lose power at WOT

[Daiken]

Just need some help looking in the right area. I have a 1977 Mercury Inline 6 1500 150hp that I lose power at WOT, but I can start right back up after the loss of power. This will happen 2 or 3 time while I'm out running around.

 

[timmathis]

Re: Lose power at WOT

Do you use the small 6 gal. tanks? If so make sure the vent is open in the cap. If that's not it have someone pump the bulb at WOT. If no help post and we can go from there. Good luck, Tim

 

[timmathis]

Re: Lose power at WOT

You said it would do this 2 or 3 times? Does it run o.k. after that? We need more info. how often does it do it?

 

[Daiken]

Re: Lose power at WOT

It stops just like the key was turned off. I have a large tank with a good vent. It has just started the last two trips out. I will be running, motor stops, I put back in neutral and turn key and it will start back up. It will run ok for a good long time then just start acting up.

 

[2cycle]

Re: Lose power at WOT

You may want to check/replace the fuel pump diaphragm (app. a $6 fix). Sounds like you are getting a vacuum leak somewhere. All it takes is a small pinhole. Also, if you have a built in tank, the anti-siphon valve could be causing the problem. I had the same thing happening with my 75 1500 and I had to rebuild the fuel pump and replace the anti-siphon valve with a standard fuel fitting. If you have an inline filter, replace that as well. <br /><br />Also, like Tim said, run a portable tank (if you have a built in one) to see if the problem still occurs. If it does, you know that the problem is in the fuel delivery. Good luck!

 

[Daiken]

Re: Lose power at WOT

I do have a inline fuel filter and will look at changing it. It will be a couple days but I will reply with more. Thanks, Dave

 

[Daiken]

Re: Lose power at WOT

b

 

[bobrock]

Re: Lose power at WOT

portable fuel tank or built in ????<br />theres a screen sock in the dip tube of a built in and they get clogged also you can tell that if the primer bulb collapses

 

[Daiken]

Re: Lose power at WOT

It is about 16 or 18 Gal metal tank. I will check that as well.

 

[timmathis]

Re: Lose power at WOT

You could have A sticking float in carb.

 

[laker925]

Re: Lose power at WOT

Clear inline filters--are they really a good investment? I have heard some real horror stories from some repair men on those things,Im still not sure on using them.

 

[Daiken]

Re: Lose power at WOT

Thanks everyone. Went and got a Fuel Pump kit. When I opened the Fuel Bowl on the pump the screen was pluged up. After installing the kit the motor runs great.