200 johnson gt cant prime

[trans80]

need some help.last year the motor was sneezing and stalling at idle and sound the fuel restriction alarm at wot.i found the fuel line was rotted and replaced it and bulb with factory repl.also found one torn oring that goes between the carb and throttle plate and replaced it. went to the lake yesterday and the primer bulb would not get hard at all.it only took two sqeezes at the house on the muffs.the only thing i did was put more fuel in the tank which was difficult while gas was spitting back out. the vent line is clear and the pickup tube was also replaced. i fixed the idle issue but the restriction alarm went off again. when it went off at wot a friend reached back squeezed the bulb and the alarm quit but the bulb collasped when he did this. the siphon valve has been eliminated.

 

[tashasdaddy]

Re: 200 johnson gt cant prime

clogged or closed fuel tank vent, if bulb sucked partially flat.

 

[trans80]

Re: 200 johnson gt cant prime

the fuel tank vent is clear

 

[mikesea]

Re: 200 johnson gt cant prime

You can test the vent simply loosening the fill cap.your problem definatly indicates aplugged line prior to the squeeze ball or a bad vent.Could the tank have something floating in it that plugges the p/u tube.If you have access to a porable tank.Try it and see if things are ok.If so.Prob in tank set up.and ,not being a wiseguy.Is the ball flow arrow pointing toward engine(installed backwards)

 

[mikesea]

Re: 200 johnson gt cant prime

sorry double post

 

[jtexas]

Re: 200 johnson gt cant prime

is there an echo in here, mike?

Only one possible cause for collapsed primer bulb: restriction upstream.
Or bad bulb.
Ok, that's two possible causes: restriction upstream or bad bulb.
Or blocked vent. Three. Three possible causes.

You don't say what year motor, but assuming a carb'd engine, it takes more than two squeezes of the primer bulb to pressurize the line, especially a multi-carb engine, and especially if starting with empty carb bowls. The bulb itself just doesn't have the fuel capacity to fill even one of your carburetors.

Not sure what to make of that, and the fact that it never got firm at the lake, yet the engine ran......some apparent inconsistencies here......

But, gas spitting and bulb collapsing are both consistent with closed off tank vent.

 

[JBVolvo]

Re: 200 johnson gt cant prime

Not sure what to make of that, and the fact that it never got firm at the lake, yet the engine ran......some apparent inconsistencies here......

I gotta chime in here.
I had a similar issue with my 87 4hp.
I'd start it and it'd run for a while (15-20min) then choke out and die on me.
I'd squeeze the bulb and it just would not feel like it was building and keeping the pressure in the line. I had a feeling it was being pulled back into the tank.

Turned out that the vent on the cap was completely closed (funky vent I'd never seen before).

So it IS possible to start and run the motor for a while even with the vent completely closed....check yours out again. Easiest way as mentioned is remove the cap and see how it does

 

[Benny1963]

Re: 200 johnson gt cant prime

had same probs with mine replaced tank fuel lines 3/8inch only. went to large evirude bulb. cleaned and tightened fuel pump screens . rebuilt primer .
basicly went thru entire fuel sys no vro,on mine though
was cheap and ran like scallded dog till it blew up ,lol
bennyb

 

[trans80]

Re: 200 johnson gt cant prime

thanks for the replies. next time out ill try removing the fill cap while underway to see if this helps.i know the tank vent is working because i removed it at the lake and could easily blow through it but it just may not be enough vent i dont know .the motor is a 90 200 gt. boat is new to me.

 

[trans80]

Re: 200 johnson gt cant prime

took boat to the lake this past week and pumped the primer bulb and still could not get pressure to build.took the fuel line off at the vro and pumped the bulb.after about 5 min of pumping i started to get a stromg stream of fuel.reconnected the line and pump primer and finally built up pressure. ran fine for about 30 min then the alarm goes off again at wot only.removed fuel cap and tested it like that with no difference.stiil got the alarm and about a 300 rpm drop at wot.could this be a vro prob? anyone delt with this before.just cant seem to find the prob

 

[jtexas]

Re: 200 johnson gt cant prime

if the vent is open, it's enough...you're sucking gas pretty fast, but not that fast.

Have you checked the tank for debris and/or water?

I'd just go ahead and get a new primer bulb (if you haven't already), those things aren't too expensive and need to be replaced every once in awhile anyway.

But yeah, I think it could potentially be a fuel pump thing.