1979 80HP Mercury

Kissdude

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Can anyone tell me, why in my driveway my engine starts every time but when I get to the lake and launch the boat, it takes for ever to start. Could this be cause the fuel doesn’t stay in line or something? Also I’m really worried about turning engine off in the middle of lake that it might not start. Any procedure on how to get it running if if doesn’t start would be appreciated. Thanks in advance
 

airshot

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Exactly what steps do you take in the driveway to start your motor ? On muffs?
 

racerone

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Help the forum help you by posting the actual compression values.----Do you raise the fast idle lever for cold starts?-----Do choke flappers close when key is pushed in , or button is pushed?
 

jimmbo

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Is it actually running on all Cylinders when on the Muffs?
 

Nordin

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When you are in the lake (water) you have back pressure from the water to the exhaust.
On muffs.......no.
As jimmbo and racerone says, check the compression and check for spark at all cylinders.
 

racerone

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Load test the battery.----Take starter apart for inspection and ohm test on armature.----These steps are important and cost no beer tokens.
 

Kissdude

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Exactly what steps do you take in the driveway to start your motor ? On muffs?
I have the motor in a 100 gallon water tank and it starts just fine with the leaver up. After it warms up I can start it with one push of the choke and one turn of the key. When I get to the lake and load boat in the water, I lift throttle leaver, push choke and it turns over. Squeeze fuel bulb till it’s hard (which is new) but it doesn’t start. After about ten minutes looking like an idiot it will finally start. Not sure what I’m doing wrong but also scared to turn engine off mid lake and having it not start again.
 

racerone

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Do you push the choke to be on all the time while cranking it over?
 

racerone

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Do choke flappers close when you push the choke button?----Are choke flappers a tight fit ( not warped)
 

Chris1956

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You should not need any choke when restarting the motor. Those motors are real hard to flood, but maybe you have done it with the excess choke.
 

Kissdude

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Choke flappers do close all the way. It almost seems like I have no fuel getting to the carbs. Does fuel empty from the line back into portable tanks? And why with a brand new bulb does it not seem to get hard when I squeeze it after travel?
 

racerone

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Bulb has to go hard.----So you have a leak.----Inspect INSIDE your fuel tank.----Some plastic tanks are junk.-----Check fuel pump diaphragm.-----Check float valves.-----Once motor has started the bulb does not need to be hard.
 

Kissdude

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I will check for leaks but I’m using the quick silver metal tanks( have 4 of them in really good shape), might have to try another bulb. In transport, does the vent have to be closed?
 

Chris1956

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Vents on portable tanks need to be open when using the motor. If the vent is closed, you will starve the motor of fuel and possibly cause a vacuum in the fuel tank.

Fuel will not empty back into fuel tank unless there is a vacuum in the tank. it will never empty the carbs back into the tank, but carb fuel does evaporate if the motor sits for hours.
 

airshot

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In your description of starting procedures you mentioned using choke then squeezing ball....should be the opposite. Plug or connect the fuel line to the motor, then squeeze ball until hard or resistance ( some do not get rock hard) then push and hold choke for a few seconds, release, lift lever then turn to start, if it doesn't fire right away push key to choke again. Mine starts best and quickly this way.
 

Kissdude

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In your description of starting procedures you mentioned using choke then squeezing ball....should be the opposite. Plug or connect the fuel line to the motor, then squeeze ball until hard or resistance ( some do not get rock hard) then push and hold choke for a few seconds, release, lift lever then turn to start, if it doesn't fire right away push key to choke again. Mine starts best and quickly this way.
Oh I see, I was leaving the fuel line hooked up all the time, maybe I should un hook for travel then? What I was saying is after a few squeezes, I would try the engine with the choke but thought I had to keep pushing choke, didn’t know I had to let go and try it.
 

Kissdude

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Vents on portable tanks need to be open when using the motor. If the vent is closed, you will starve the motor of fuel and possibly cause a vacuum in the fuel tank.

Fuel will not empty back into fuel tank unless there is a vacuum in the tank. it will never empty the carbs back into the tank, but carb fuel does evaporate if the motor sits for hours.
What does one do after fishing on lake with motor off for about an hr? What’s the procedure for starting up again if it doesn’t start right away?
 

jimmbo

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What does one do after fishing on lake with motor off for about an hr? What’s the procedure for starting up again if it doesn’t start right away?
Turn the Key, it it doesn't catch and run, give it a bit of Throttle. Unless you are boating in sub-freezing Temps, the Motor isn't going to cool down too much in an hour.
If it still doesn't want to run, try a bit of Choke, with the Throttle still advanced
If still no Joy, the Engine needs some work. Compression Test, Ignition Inspection, and Fuel System Inspection.
 

Chris1956

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The motor must crank with the choke button pushed and held, or she will not choke. You should only need to choke the motor once a day, when first starting. Of course, if she doesn't want to restart, a bit of choke (1-2 sec) when cranking can help start 'em.
 
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