# mercury 40 hp



## Dillusion (May 21, 2012)

Sounds normal...every primer ball I have ever owned has needed to be primed again after 30 minutes. Not out of the ordinary.


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## steve77777 (Nov 12, 2013)

thx


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## Creek Runner (Sep 1, 2011)

> the boat runs great but sometimes idling and going slow the ball gets soft and engine dies, and also if i turn it off for 30 minutes the ball is soft.I ran it for 30 minutes with no problem then i docked it ,waited 30 minutes started back up then tried to go and stalled out ,bulb was soft  then i squeezed the bulb a bunch and it started right up and took off and ran great again,the mechanic said bulb looks kinda new-could this be a bad ball? has this happened to anyone of you,please help thankyou....



Going to have to disagree with you on this one Matty, no engine should stall from idling or going slow. Either its loading up or starving for fuel. 

Also there really shouldn't be a need to pump the primer bulb after setting for 30min. 4 Hours yes but not 30min.


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## mark_gardner (Mar 18, 2009)

> > the boat runs great but sometimes idling and going slow the ball gets soft and engine dies, and also if i turn it off for 30 minutes the ball is soft.I ran it for 30 minutes with no problem then i docked it ,waited 30 minutes started back up then tried to go and stalled out ,bulb was soft  then i squeezed the bulb a bunch and it started right up and took off and ran great again,the mechanic said bulb looks kinda new-could this be a bad ball? has this happened to anyone of you,please help thankyou....
> 
> 
> 
> ...



I agree with creek   my guess is that its starving, possibly a leak....how old are your hoses and primer bulb ?


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## steve77777 (Nov 12, 2013)

well i bought the boat used like 3 months ago and have had this issue,the primer bulb looks new and hoses look good,question would the leak have to be from the primer bulb to the engine? or from the bulb to the tank? and is there a way to find this leak? should i replace the ball first then if its not that go to the next thing since the ball is i guess under 30.00..? its kinda weird when it does it just random but when its doing it i just squeeze the ball and its good again for awhile.


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## steve77777 (Nov 12, 2013)

also could it be the tank is in the front of the boat?does this play into anything?


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## HaMm3r (Dec 11, 2006)

I too must disagree about the primer bulb losing prime. I pump it a couple times at the start of a trip and never touch it again the entire day. There may be half a day fishing in between motor runs and it still stays primed. Even after trailering a couple hours home sometimes, it just fires right up for driveway flushing.

I run a Merc 25hp, 2-stroke and use one of the new EPA-mandated tanks with the old-style, non-EPA approved cap. Just for comparison purposes.


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## Dillusion (May 21, 2012)

Oh, I must have forgot about that part of his post while addressing the need to reprime after thirty mins issue.

Yes losing prime at idle isn't normal...my engine idled for 20 minutes today at the ramp without dying out in neutral.


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## steve77777 (Nov 12, 2013)

im gonna put a new bulb on and ill let you know in a few weeks if it fixes the problem ,thankyou everybody


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## steve77777 (Nov 12, 2013)

so i put a new primer bulb on and ran it through no wake zones today for 2 hours and every ten minutes it would putter and stall ,then finally when i heard it start to stall i would pump the ball and it would run another ten minutes,now process of elimination ,could it be the anti syphon valve or could the water seperator have anything to do with this? any help would be appreciated thx....


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## DuckNut (Apr 3, 2009)

All other items are just a guess but start eliminating the obvious and cheap.

The primer bulb is an easy way to siphon. If the siphon is working and then stops it is because it has air.

My first and simple guess would be to replace all of the fuel line, clamps, fittings and filter under the cowling. Air up high means siphon stops working.

Also, make sure you are not creating a suction on the tank.


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## steve77777 (Nov 12, 2013)

ok all fixed,i hooked new gas tank up, then the same thing happened then i took it and had the fuel pump diaphragm replaced and all is running perfect,it wasnt pumping while in lower rpms but at higher speeds it was pushing harder so the seals where working but only at higher speeds


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## 'Nano-Skiff' (Aug 27, 2012)

I love it when there is an answer on these types of threads. Have fun.


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