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Primer blub never gets firm. 1995 150hp

M

mcgurk

Member
The motor is 1995 150HP ocean runner. I’ve been working on solving a lack of power at WOT. She won't go over 4500 RPM. Compression normal, rebuilt carbs, replaced cracked primer blub, and yesterday I found a small crack in the fuel line that attaches to the fuel strainer on the engine. I had seen small air bubbles inside strainer when squeezing the blub. After the hose repair, no more bubbles. However the blub never gets firm like on my old mercury outboards. Is this normal for this motor?
 
Re: Primer blub never gets firm.

No, that's not normal, it should get hard. Hold the bulb in a vertical position with the arrow facing up..... pump it. If it does not get hard, I would assume that either the valves in the bulb are faulty or you have fuel leaking like mad in the powerhead section somewhere.
 
Re: Primer blub never gets firm.

Thanks, I didn't think it was normal but a confirmation from one who knows is always welcome. The bulb is brand new, but that doesn't mean it is good.

I thought I fixed the only fuel leak with the six carb rebuilds. A brass BB seal was missing in one of the plastic carb bowls. I don't know how long that was an issue. I replaced the bowl.

I'll look for any other possible leaks tomorrow, but at least now I know what is normal regards the primer blub.
John
 
Re: Primer blub never gets firm.

If you have that silver colored fuel line and it is more than a couple of years old it could be causing your problem. The stuff swells internally until the supply gets restricted. Here's how I diagnosed mine. Take fuel line off at engine, as in remove the fitting from the line. Put that in an empty tank. Pump the primer bulb. You should get unrestricted full pulses of fuel every time you pump the bulb. If not, you have a bad bulb, or a restriction or air leak.
 
Re: Primer blub never gets firm.

All fuel lines are black. Not silver. I'll keep looking for a air leak in the fuel delivery system. I'll let you know what I find.
John
 
when installing carbs on motor using grese fill grove then install o ring . this will prevent fuel leakage between carb and throttle body vst seal should be done as well.fuel bowls are enexpensive when cleaning or replacing make sure high speed jets are tight if your bowl drian screw does not have a tit on the end ask dealer for this style. due to expansion of the plastic the high speed jets can back out restricting fuel and burn up your motor. hold steady pressure on primer bulb manualy turn red choke valve to see if it leeks.
 
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