yamaha priming

richard sparks

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Aug 20, 2012
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I have a 1984 50 HP Yamaha, removed and cleaned all three carbs. The hose bulb is hard as a rock, but I can't get any gas in for priming. After squarting a little WD-40 in the carbs, it starts and runs fine. What is the problem? Thanks
 

cmchb1

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Aug 16, 2012
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Re: yamaha priming

Did you check if carb have gas in it. Maybe The flotter regulation is to low. Did you clean buildup rust every where. Did you remove all screws and check inside. Some times the main chamber is clog.
 

Capt Ken

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Jul 30, 2002
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2,269
Re: yamaha priming

Sometimes the little valve where you connect the fuel line doesn't compress and won't allow fuel to flow to the engine. You can check it by removing the fuel line at the fuel filter and see if when you squeeze the bulb, fuel flows through.
 

richard sparks

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Re: yamaha priming

Did you check if carb have gas in it. Maybe The flotter regulation is to low. Did you clean buildup rust every where. Did you remove all screws and check inside. Some times the main chamber is clog.

Yes, the bottom hose is clear, I can see the gas going into the carbs, and it goes in easy until the float stops it. Once the carbs are full and the ball is hard I cannot force any gas into the carbs for starting.
 

99yam40

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Re: yamaha priming

Apparently if the carbs are full of fuel, then your choke is not operating properly or your starting procedure is wrong
 

robert graham

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Apr 16, 2009
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Re: yamaha priming

Yes, the bottom hose is clear, I can see the gas going into the carbs, and it goes in easy until the float stops it. Once the carbs are full and the ball is hard I cannot force any gas into the carbs for starting.
The primer bulb fills the float chambers, the float needle valves close preventing any further fuel from being pumped into the chambers(just like in the back of a toilet), and the ball gets hard like it's supposed to. Like 99yam40 said, you have a problem with your fuel mixture enrichening device(choke or prime start).
 

richard sparks

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Re: yamaha priming

The primer bulb fills the float chambers, the float needle valves close preventing any further fuel from being pumped into the chambers(just like in the back of a toilet), and the ball gets hard like it's supposed to. Like 99yam40 said, you have a problem with your fuel mixture enrichening device(choke or prime start).

On my 1984 50 HP ETLN motor there isn't a prime start, if there's one where is it located? The chokes are pulled in manually. There is a solenoid that is connected to the three chokes, does this solenoid open or close the chokes?:mad:
 

99yam40

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Re: yamaha priming

should close the butterflies when you hit the choke switch.

Is there a reason you have not looked at them when operating the switch to see what they do and if they are closing all the way like was said?
 
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