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1998 J70 Any Thoughts?

A

Asport-16

Contributing Member
Ok so ill try this question. I have a 1998 Johnson 70. I put new carbon reeds and new fuel lines from tank to motor, rebuilt the carbs(think i was to meticulous setting the float levels) i have a service manuel so went by specs. I put a new water pump in also. It starts right up and runs good, big improvement since the install of the carbon reeds. Im on the Peace river so you have to cruise just above idle because of the sandbars here. It stalls after a while and it wont start again. Seems like when i try to pump up the bulb its full of air. I have a 20 gal internal tank that i cleaned out good. This never happened before i put the reeds in. After bout an hour of paddling I tilted the motor up fully and started the key and it kicked over. Put it back in the water and ran fine again like it never happened. Even though I did all the work myself my experience is limited. I havnt performed the link and sink yet. Im taking her back out and just going to go up and down the river with the boat ramp in sight to see if it happens again. Any thoughts on what this problem could have been? What should be done next for my engine? It has 140 psi across the board. Full tank of non ethanol. Water separator installed with new filter. Ive only been behind the wheel of this boat for six months and on this river, if you break down you might be out there a very long time with just alligators to rely on a tow. Lol I may be missing something because of me missing experience. Could there have been air in my line? Could a carb float been stuck? Any feedback would be great? Thanks
 
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Did you replace the primer bulb or just the fuel line? The bulb could have a bad check valve is allowing fuel to flow back into the tank. Also, have you checked the fuel pump diaphragm for pin holes? It could be you don't have a good seal on the pump and it's not drawing up enough fuel to supply the engine.

Those 70's will sip fuel at low speed so it could be you're idling on what's in the float bowl and then it finally runs out.
 
Not sure what your reply to post # 3 is saying.----Are you saying that you have test run with a " known to be good " tank and hose , yes or no ?
 
I said I installed brand new lines from the internal tank in the boat to a new water separater to a new bulb to the motor new fuel lines under the cowling too. It must of been water from sitting settled somewhere from condensation then got to the motor because on my second outing i ran it for 4 straight hoursand no problems. Im More Concerned with the high idle seems as though it is stuck in quick start idleing way to high. I try to just keep it in 1 gear.
 
Okay, you likely have 2 separate problems. When it had air in the line, there has to be something in the check valve of the bulb and /or a way for air to get into the line between the bulb and fuel tank. This includes the verticle tube and fitting in the tank itself. I had an integral tank a couple years ago start sucking air where the vertical tube in the tank couples with the elbow on top of the tank. Have seen this even more commonly with cheap plastic 6 gallon tanks too.
High idle can be a huge host of things.
 
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