MERC 5.7 STALLS AFTER SITTING 15-20 MIN IN HOT WEATHER

[casadelago]

Hello fellow trouble-shooters!,<br /><br />I have a 2003 Ski Centurion 5.7 Merc mid engine, carborated direct drive ski boat. I have a problem with a "Stalling No Fuel" issue, @ higher outside air temps...I thought I would run by you guys before I contact the dealer, hoping that one of you have run into this problem before since there are a million boats out there with this engine set up.<br /><br />The Problem: After the boat sits (after a morning of sucessful skiing) the boat will re-start right up (no problem) but will die shortly after you apply the throttle, This only happens when the outside air temp is hotter than 90Deg. (runs fine in the winter @ 70-85Deg) Once the engine dies it takes about 3 minutes to get fuel back in it and it runs fine until your next intermission. The engine Temp is constant 175 Deg, and all other gauges check OK, I have pulled the cover to see if I am getting extreme heat in the engine compartment (barely warm)and thinking it may be a vapor lock in the fuel line, or possibly a faulty sensor to the fuel pump? or could it be something else? Sometimes you can save it by pumping the throttle when it is starting to die, nothing else is wrong and it runs great as long as I don't take long intermissions before each ski run.<br />Any I deas or help from the group would be appreciated.

 

[TwoBallScrewBall]

Re: MERC 5.7 STALLS AFTER SITTING 15-20 MIN IN HOT WEATHER

Vapor lock sounds likely. <br /><br />

(runs fine in the winter @ 70-85Deg)

and oh yeah, I hate you... <br /><br />Just kidding of course!

 

[casadelago]

Re: MERC 5.7 STALLS AFTER SITTING 15-20 MIN IN HOT WEATHER

Steve,<br /><br />If the problem is vapor lock, what would be some suggestions? I have tried the cap, the fuel lines are new, no kinks etc...<br /><br />Thanks...

 

[Trent]

Re: MERC 5.7 STALLS AFTER SITTING 15-20 MIN IN HOT WEATHER

Install some insulation on the fuel lines in the engine compartment.

 

[Blk-n-Blu]

Re: MERC 5.7 STALLS AFTER SITTING 15-20 MIN IN HOT WEATHER

Cas, One thing you could try if your not already doing it is let the engine idle in neutral at about 1200 RPM for several minutes after running hard before shutting down. It seems more people are having this problem due to changes in gas formulations.

 

[rodbolt]

Re: MERC 5.7 STALLS AFTER SITTING 15-20 MIN IN HOT WEATHER

you may also try adding the merc low pressure fuel pump kit to help prevent vapor lock and maybe the merc cool fuel cannister.<br /> sounds like its a fuel boiling in the lines (vapor lock) problem. remember fuel under a vacum can boil at 50*F.<br /> good luck and keep posting

 

[casadelago]

Re: MERC 5.7 STALLS AFTER SITTING 15-20 MIN IN HOT WEATHER

Trent / Blk-n-Blu / Rodbolt,<br /><br />...is there a chance it could be a sensor? I will try all recommended solutions and appreciate the help. We will be heading up there next wk-end so I'll provide feedback... Thanks Again!