Merc primer bulb won't get hard

grandx

Petty Officer 1st Class
Joined
May 21, 2001
Messages
383
Can anyone suggest why my primer bulb wont get hard. It's a new bulb, no anti siphon device in line. ?Bad bulb??? would fuel pump sealing or check valve cause this??
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Merc primer bulb won't get hard

It may be the primer bulb,EVEN if it is new.<br />There have been a bunch of bad ones found.<br />But one question, does gas leak from the carb(s)?
 

grandx

Petty Officer 1st Class
Joined
May 21, 2001
Messages
383
Re: Merc primer bulb won't get hard

Never seen gas leaking from carbs, I feel like I can't get any gas to the carbs. We have fuel tank, water separator, bulb, fuel pump, inline filter, carbs in this order. You'd be there a long time getting the see thru inline filter full of fuel. I usually give up when I can get it 1/2 full, then it usually starts, with a little choke and throttle maybe. I feel fuel moving in the bulb, feels like it comes in from the tank and right back to it,with a little going the right direction each time. Bought fuel pump kit to put in this weekend to stop gas leaking from pump (I've only seen this happen when I'm lucky enough to get the bulb hard). Almost bought another bulb too, but I can get one later if need be, Know how to test a bulb, or where would you look next, I'm planning on the fuel pump kit not solving all the problems...
 

boatmotor

Seaman
Joined
Jan 22, 2001
Messages
54
Re: Merc primer bulb won't get hard

Hi Grandx Not to be smart but did you<br />connect bulb in right direction. <br />Regards Tom
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Merc primer bulb won't get hard

LOL,yea boatmotor,it don't hurt to ask, but mine did that on my 120force and 7.5merc, and it was a new primer bulb in both cases. But yes, that would give the same result
smile.gif
<br />Also, remove the pickup tube from the fuel tank. If it has a little ball inside of a cage-like thingy on the end of the tube,take it off and sacrifice it to the toilet-god.<br />It's a worthless device called an anti-syphon check ball,and it will never work the way it was designed to...So toss it.
 

grandx

Petty Officer 1st Class
Joined
May 21, 2001
Messages
383
Re: Merc primer bulb won't get hard

no anti siphon in line, and yea, no offense taken here, but the bulb flow arrows are pointed to the engine and not the fuel tank. I welcome all possibilities, keep em coming. I'll bet between us we have it fixed by Sunday.<br /><br />Thanks for the posts
 

Bluefish

Petty Officer 2nd Class
Joined
Mar 14, 2001
Messages
125
Re: Merc primer bulb won't get hard

Had this problem for years with my O/B for me its been the floats in the carbs, I think that they are not/stop seating in the bowls. Samething as you? hard to start,must choke and throttle to start engine.My problem is the boat stays in the water for the season, so I keep the engine tilted up and some of the gas runs out and the floats aren't seated when not using the boat and this is letting the floats get stickey?? What I do is remove the overflow hose on the carb and spray crab cleaner gum out in let it sit 5min and start the engine to run it out.It's allways worked for me.<br />Good Luck
 

grandx

Petty Officer 1st Class
Joined
May 21, 2001
Messages
383
Re: Merc primer bulb won't get hard

I put fuel pump kit in, leak stopped, put a new bulb in. Engine seems to idle fine in the back yard with garden hose hooked up. Plan on going out next weekend, will post results next Monday.<br /><br />dg
 

grandx

Petty Officer 1st Class
Joined
May 21, 2001
Messages
383
Re: Merc primer bulb won't get hard

Motor ran fine this Saturday, thanks for everyone's input. Looks like I discovered a leak on top of the trim cylinder though. I'll try my hand at this next. Thanks for everyone's help.
 
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