70hp johnson multiple problems?

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scsdiver

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Location
Edgewater, FL
so i have been dealing with multiple problems with my outboard. the first is i have had two tanks of bad gas which i believe now keeping my tank full of gas has solved that problem and obviously not a motor issue. i installed a fuel cell in front of my 17' tracker and installed a new fuel line. the motor is fairly new to me and i am not sure if the previous owner ran ethanol free gas or not however i am running standard gas from a good station. my problems are the motor is seems to clog very quickly on the water side. i have installed a new impellor and upgraded cup as well as all gaskets and seals in regards to lower unit and the water pump. however if we get into a silty area or drive through a shallow spot for no more than a minute the water system seems to get clogged and it stops peeing. it is clogged enough that it will put the motor into idle mode. the happens whether in shallow water or just running. we went out yesterday and were never in shallow water but where in some silty spot and it stopped it up so my question is that every time i go out i have to come back and clean out the water jacket as best i can and the seems to be ok. is there a better way to do this or is there possible something that needs inspected, replaced,cleaned?? having to take the motor apart everytime i get home is ridiculous. secondly i have a intermitent fuel issue. somedays it runs fine no problems somedays it doesnt like to idle after running, sometimes it quits running at idle sometimes seems like its starving for gas. at times the primer bulb is full, sometimes its not. its almost like i have a vacuumm problem and a air leak?? any ideas would be great.
 
That sounds like a long way to pump fuel from the front of the boat to the back without a little help but I dont know... Have you checked all of the seals on the water tube to make sure that they fit good and tight on the tube and that the gasket under the water pump is sealing good and the intake is clear? Just some things that come to mind...

Steve
 
in regards to the fuel line i think we have several problems there to. im going to replace the old line from the fuel pump to the carbs as i dont know how old it is and it sat unused for 2 years. i think our second problem is that the deck filler we installed has a vent/overflow connection and we have found that the lid is sealed so it does not vent. so i think we are having a vacuum issue as well. not sure if the length is a issue or not the total length of fuel line is about 11 or 12'. however the oddity is when we have fuel line issues it seems as though the primer ball does not stay firm like there is a air leak.

in regards to the waterpump. i am 100% certain everything is good in the lower unit it is all new and i already had someone else tip me off that i had the cup not in quite right the hole was off so i have fixed that. the screen and everything below the pump seems clean and in good shape. the problem i think is in the block. the tube and all the seats are new and good. when the motor stops peeing i remove the thermostat and blow air back through where the indicator line comes out of the exhaust manifold and usually some crud comes out. ill put the thermostat back in and hook water up and it pees a good stream. so with that said i think there is some kind of blockage inside the block maybe? we had a lot of wasp nest and dirt dobbers around the motor and inside the exhaust cavity.
 
If the tank isnt vented then it will loose prime. Ever try it with the lid open and the cap loose to see what it does? As for the water pump, wonder if there is a piece of old impeller floating around in there. Or like you said wasp nest or mud dobbers nest in there. when it does this have you ever went home and put muffs on it and ran it? To see if it pees then?

Steve
 
acwd said:
If the tank isnt vented then it will loose prime. Ever try it with the lid open and the cap loose to see what it does? As for the water pump, wonder if there is a piece of old impeller floating around in there. Or like you said wasp nest or mud dobbers nest in there. when it does this have you ever went home and put muffs on it and ran it? To see if it pees then?

Steve
yes i have gone home and put muffs on it and still does not pee and visually the screen in the lower unit looks clean before i hook them up. i have tried running it with the cap off and unfortunately i cannot say for certain it is better or worse. as it only has the fuel issue some times. i cant say it happens on warmer days than colder days it is very random i have been trying to find some sort of pattern to the issue but i cannot seem to find one. my next step is to switch back to a portable tank that is closer to the motor and will rule out anything before the fuel pump.
 

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