1998 Mercury 90HP Stalling at Slow Speeds

[Oldsaltydog]

Starts easily, idles fine, runs really well, except it sometimes stalls while running in gear at around 1100-1200 rpm, and the primer bulb usually goes soft. But it will start right up after the bulb is primed. Seems like a fuel starvation issue. Any suggestions? (Cleaned carbs, new fuel filter, new plugs, and rebuilt fuel pump.)

 

[achris]

Re: 1998 Mercury 90HP Stalling at Slow Speeds

Silly thing to say, but have you checked that the tank vent is open?

 

[Oldsaltydog]

Re: 1998 Mercury 90HP Stalling at Slow Speeds

Yes, it's open. Thanks for responding.

 

[bryanredfish]

Re: 1998 Mercury 90HP Stalling at Slow Speeds

Sounds like the low idle jets are clogged. May be time for a carb job.

 

[2springers26]

Re: 1998 Mercury 90HP Stalling at Slow Speeds

primer ball& fuel pump update need to be done on ALL motors Built 2000 & older....( new fuel arre effecting old style parts) if your carbs are Clean do the fp & p ball update....

 

[Wellcraft 89]

Re: 1998 Mercury 90HP Stalling at Slow Speeds

2springers,do you want to fill us in on what your saying.is there a service bulletin on this?????<br /><br />Rich

 

[2springers26]

Re: 1998 Mercury 90HP Stalling at Slow Speeds

I'Ve attended many mercury training schools in the past 4 years.. the # 1 preach Is primer ball & fuel pump update... all Motors Built 2000 & older Should have the new primer balls( yellow rib on it)& square fuel pumps rebuild with new Kits... the new fuels of today are eating the rubber parts... fp// check valves are now clear plastic not rubber... I probbly find 5-10 boats a week that are Not laying flat... Most comon complains run ruff.. seems to flood, won't idle... If the valves are not flat... That cyl will flood.. for less than $25.00 In parts it well worth the update...

 

[Oldsaltydog]

Re: 1998 Mercury 90HP Stalling at Slow Speeds

Thanks 2springers26 for your reply. I have already rebuilt the fuel pump -- including the clear plastic check valves. And I will certainly buy a new primer bulb!