1988 Mecury 45HP Classic Fifty

[mremy]

Hi there,
I have recently purchased a 1988 Merc 45 HP Classic Fifty outboard. I have yet to have it in the water but it seems to do ok with hose and ear cups. However, I noticed some residual fuel leaking fromt he carborator when the engine is fully tilted back. Also, when I prime the ball, fuel pours through the lower carb. The shop who put it in says this is because this motor has spring loaded needles and too much pumping will cause the fule to by pass the carb. I didnt think I pumped too much, just normal, until it was hard. Is this explanation sound legit, or should I worry?
Thanks
Mike

 

[verado7]

Re: 1988 Mecury 45HP Classic Fifty

thats a great motor i have the exact same one , it is normal for some fuel to spill out when the motor is tipped up , as far as overpumping the bulb yes you can if you you really try - just pump ball just till it fells hard -not like a rock but just firm and hold it there if it loses pressure look to see if fuel is leaking out carb if so float needs adjusting but chances are you need to rebuild them (very easy to do) as its probably the needles that aren't seating anymore- it could also be the prime bulb that is leaking back to the tank thru the one way valve in the bulb replace bulb ....if you do a carb rebuild i found the best float settings was parrelel to the bowl with carb upside down .

 

[Grizzlybear]

Re: 1988 Mecury 45HP Classic Fifty

I got the exact same motor and have found it way too easy to flood when you are priming it with the ball. I actually never use the pump at all now, starts without it. I heard the same thing about the fuel by-passing.

 

[verado7]

Re: 1988 Mecury 45HP Classic Fifty

if you are able to flood it with the bulb either you are priming way to hard or your floats aren't set properly and if its been a few years it's time for a new needle and reset the floats . you should not be able to flood the engine by priming .

 

[AMD Rules]

Re: 1988 Mecury 45HP Classic Fifty

Flooding the engine, or having some gas pass the seats are related but separate topics.

weeping needle/seat
Yes, even a good needle/seat will allow fuel to pass if you keep squeezing once its firm. They're not a perfect seal and are not designed to hold large pressures. Leaking some fuel is not surprising. Suggestion is not to over pressurize, as it also stretches out your fuel pump diaphragm reducing its life. You can hear the carb bowls filling... stop when they are full.

hard starting - flooding the crankcase with fuel
If you actually flood the motor easily, and make it difficult to start, then I'd agree that the needle/seat is worn and should be replaced.

Thats a really nice motor you have.

Good luck on the water.