primer bulb questions...cant keep prime!

steve forsythe

Petty Officer 1st Class
Joined
Nov 7, 2001
Messages
245
When starting boat, i prime the bulb and she takes 3 or 4 long cranks, with choke, to start and stay running. Some times i have to put it in neutral and rev it to get her going. (200hp Merc carbed,year 2000) When i check the bulb it is half soft. Same thing when running for awhile and then cutting her off for 20 minutes, she wants to start but sputters and dies unless i rev it a little. Again soft prime bulb. QUESTION- Do i just buy a new bulb, or is there somewhere else to look for this problem like vents or something. I dont know much so please explain as much as possible. Thank you,
 

Pursuit2150

Chief Petty Officer
Joined
Dec 3, 2001
Messages
553
Re: primer bulb questions...cant keep prime!

I am assuming you have a built in tank,if so it is vented.If you are using portables,you need to open the vent to prevent vacumn.<br /><br />It sounds to me like a bad check valve in the bulb,also check for kinks in the fuel line or possible obstructions.<br /><br />To check for obs.you will need to disconnect lines and blow them out.<br /><br />Try that 1st,without going to possible other problems,for an engine that new,I hope the simple solutions work.<br /><br />Come back with how you made out.
 

petryshyn

Commander
Joined
Oct 3, 2001
Messages
2,851
Re: primer bulb questions...cant keep prime!

Purse*Snatcher <br /> Does your problem go away if you maintain a hard primer ball by hand, or is the soft ball just an observation?
 

steve forsythe

Petty Officer 1st Class
Joined
Nov 7, 2001
Messages
245
Re: primer bulb questions...cant keep prime!

When i prime the bulb by hand it helps a lot BUT, i feel like the bulb doest actually get fully hard. I feel like it used to get fully hard but now, no matter how many times i squeeze, it doesnt want to get or stay fully hard. Ive seen the bulbs for sale in West Marine with a hose attachment, should i try one of those?
 

Pursuit2150

Chief Petty Officer
Joined
Dec 3, 2001
Messages
553
Re: primer bulb questions...cant keep prime!

You can buy a bulb w/o the hose at K or Wal-mart, or any marine store.
 

steve forsythe

Petty Officer 1st Class
Joined
Nov 7, 2001
Messages
245
Re: primer bulb questions...cant keep prime!

Being that i am not sure how to "blow" out the lines to see if they are obstructed, would that be your first step, buying a new bulb? If that doesnt work are there easy vents to check besides the one in the side of the hull? I have a 120 gallon below deck fuel tank. Thanks.
 

Ross J

Lieutenant Junior Grade
Joined
Nov 30, 2001
Messages
1,119
Re: primer bulb questions...cant keep prime!

A few things you could check. If the bulb remains soft to feel then the fuel pump sucking fuel into the motor may be at fault. Should pumping by hand improve this then its the pump! As you state the fuel tank is a large one and this could be enough with a tired pump to cause this problem. It sounds most likely though to be in the area of an air lock or such. Can you empty the tank? If so then a visual check can be made of the entire fuel line for possible blockages and inspection of vents, or valves at the primer. Replacing the primer bulb with its fuel line would eliminate this problem.<br />Ross
 

Pursuit2150

Chief Petty Officer
Joined
Dec 3, 2001
Messages
553
Re: primer bulb questions...cant keep prime!

The bulb would the quickest fix.If there is an obstruction, you can disconnect the fuel line at the tank and at the bulb input side and blow it out with a portable compresser, or by mouth.Should only take 5 min.just make sure the clamps are tight.<br />I didn't want to get into the fuel pump possibility,try the simple fix 1st.
 

rbu

Seaman
Joined
Jan 17, 2002
Messages
66
Re: primer bulb questions...cant keep prime!

I would just replace the bulb.<br /><br />Fow what it's worth, my experience has been that the Tempo brand bulbs suck. I would advise getting one from Merc, OMC or Yamaha.
 
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