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mercury classic 50 problem??

butchyday68

New member
over the weekend i decided to sea foam my carbs. when i sprayed the top carb it bogged the motor as it's supposed to do. however when i did the bottom carb. there was no change. this motor is on a 24 foot pontoon and my top speed is about 10mph. my thoughts are it should do alittle better than 10. i am suspecting it's only running on top carb. any thoughts??
 
I am thinking that there is a spark problem on bottom 2 cylinders.-----Do a check for proper spark on all cylinders , It should jump a gap of 7/16" or better.------------------------If bottom carburetor was working the motor should have bogged down with the spray.----If bottom carburetor was not working it should have run better ( responded ) to the spray of seafoam.
 
Those motors will run on 1 carb but not well. I would remove both carbs and clean them well. What I found with mine was the float needle got stuck in the closed position ... very common if you have original OEM rubber tipped needles. You will need a pair of needle nose pliers to get it unstuck, tapping it won't work. Unfortunately there is nothing that you can do to free the needle in the bottom carb without removing it. The ethanol in the fuel causes it to swell and stick in the seat ... happened to me 3 times!

I am now running an enzyme additive that is supposed to stop that. As a practice, I pull my fuel line with the motor running at the end of an outing and burn some of the fuel out of the bowl. Not run it dry, but enough to allow the float to drop, therefore the needle is not in the seated/closed position.
 
took both carbs off just to clean, check them. did notice a slight difference in the resistance in the floats. the bottom carb had a slight bit more than the top. however after i got both cleaned and reinstalled they are both working great now. just have to get it in the water and try it out. thanks for the help guys!!
 
took both carbs off just to clean, check them. did notice a slight difference in the resistance in the floats. the bottom carb had a slight bit more than the top. however after i got both cleaned and reinstalled they are both working great now. just have to get it in the water and try it out. thanks for the help guys!!

Butch, How is the toon running now?
 
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