Mercury Optimax Stalls at high RPM

edgpr

Cadet
Joined
Dec 9, 2009
Messages
24
HI,
I have a pair of 2001 mercury optimax 150hp on a 25' footer. Last time i went out one of the engines was running perfect at low rpms (uder 2000rpms) but everytime i would go over 2K rpms it will run fine for about 15 seconds and then stall and die. You can crank right back up without a problem and it will idle, but at this point you can open wide throttle and rpms won't go up past 1500. if you let it idle for 5-10 minutes, it will work again for another 15 seconds or so. Im guessig its getting flooded with gas, but i really don't know where to start looking. Any help will be appreciated. Thank you.
 

edgpr

Cadet
Joined
Dec 9, 2009
Messages
24
Re: Mercury Optimax Stalls at high RPM

Also, the temperature stays cold, there are no beeps or any other indications that something is wrong...
 

Big flop

Petty Officer 1st Class
Joined
Apr 6, 2011
Messages
290
Re: Mercury Optimax Stalls at high RPM

From your discription it sounds like the VST tank
is running out of gas.
maybe filters, primer bulb, anti-siphon valve,
Fuel line coming apart inside, bad lift pump,
Plugged VST filter,
Install fuel pressure gauge and watch
for lost pressure.
 
Joined
Oct 28, 2010
Messages
923
Re: Mercury Optimax Stalls at high RPM

Duplicate the secenario again and drain the VST into a graduated cylinder and record amount, then pump the primer bulb until slight pressure is felt and drain into same container. If your amounts vary you could have possible fuel restriction/lift pump problem, if they pretty much equal I would suspect the low pressure fuel pump. Are you the orignial owner? If you are, did you receive a letter about direct injector recall as per service bulletin 2001-01.
 

aussieflash

Lieutenant Junior Grade
Joined
Feb 5, 2011
Messages
1,004
Re: Mercury Optimax Stalls at high RPM

If you have a manual I would be checking the EFI system first.Could also be ignition/ timing related.
 

edgpr

Cadet
Joined
Dec 9, 2009
Messages
24
Re: Mercury Optimax Stalls at high RPM

Duplicate the secenario again and drain the VST into a graduated cylinder and record amount, then pump the primer bulb until slight pressure is felt and drain into same container. If your amounts vary you could have possible fuel restriction/lift pump problem, if they pretty much equal I would suspect the low pressure fuel pump. Are you the orignial owner? If you are, did you receive a letter about direct injector recall as per service bulletin 2001-01.

No, im not the original owner. I bought it about a month ago so im not sure about the recall.
 

edgpr

Cadet
Joined
Dec 9, 2009
Messages
24
Re: Mercury Optimax Stalls at high RPM

What temperature is it reading?

It's cold, the needle is all the way at the bottom of the gauge.

Duplicate the secenario again and drain the VST into a graduated cylinder and record amount, then pump the primer bulb until slight pressure is felt and drain into same container. If your amounts vary you could have possible fuel restriction/lift pump problem, if they pretty much equal I would suspect the low pressure fuel pump. Are you the orignial owner? If you are, did you receive a letter about direct injector recall as per service bulletin 2001-01.

No, im not the original owner so im not sure about the recall.
 
Joined
Oct 28, 2010
Messages
923
Re: Mercury Optimax Stalls at high RPM

If problem persists, and you can not figure it out, may want to look into it. Take it to a dealer and they can determine whether it has been done by looking at the injectors, serial number, or Mercnet. I think they have to call tech service to get approval. Verify temp at Tstat with pyrometer.
 
Top