Hesitation at WOT 82 johnson 70hp J70ELCNB

[Evinrude Trouble]

I have a 1982 johnson 70hp Sea Horse Model# J70ELCNB and am having some problems with hesitation at WOT and the remote control box periodically buzzes. I have Replaced the fuel pump diaphram, replaced all the carb jets (expensive) and rebuild all three carbs, I replaced all fuel line with 3/8 gas hose with an inline filter. We did not used to have this priblem this is a recent thing the motor used to run fine without this hesitation. The boat will jump out of the hole just fine but the problem is noticed after the boat is on plane. It sounds and feels like someone is cutting back the throttle ever so slightly and thne pushing it back up to WOT and when the throttle cuts back it lasts for 2 or 3 seconds then back up to WOT then cuts back for a second kind of like a yo-yo, the motor also vibrates a little more than it used to. My second problem is that it sounds like a buzzer is going off in the control box and i have been told that this is an over temp alarm? This problem also happens intermitently and the tell tale stream is strong when it happens and it has happend when we are at WOT and when we are in neutral and have not run the motor long. Does this alarm have a thermostat that could go bad or could this be a short. I dont think the motor is over heating. I am going to replace the ignition switch because it really needs it. Another more frequently posted problem is that I dont feel like i am getting top end on the motor. I have checked the timing and it seems to be spot on for what the manual says. Have recently replaced the spark plugs. Any help with any of these problems would be greatly appreciated, thanks for reading.

 

[mikesea]

Re: Hesitation at WOT 82 johnson 70hp J70ELCNB

the hesitation sounds like you may be leaking spark through a bad plug wire or cracked coil,I think this because you say the carbs and fuel pump etc were done and I assume done correctly.you might try putting a good set of wires on the eng.the a;arm I think is an impeller,not getting enough at high and low speds,the tell tail indicates you are pumping,but not how much your pumping,if the impeller wasnt changed ,start there,it should be chanbged yearly,with gear oil

 

[Evinrude Trouble]

Re: Hesitation at WOT 82 johnson 70hp J70ELCNB

It probably is due for a water pump rebuild and i have done the carbs, and fuel pump by the book with sierra parts. I still dont think i'm getting top end and i dont have a tach to see what kind of RPM i'm turning out. I checked the timing but i have read about this link and sync procedure. If timing is spot on what kind of adjustments do i need to make to carbs? Butterflys are wide open when throttle is wide open, the cam that acuates the carb linkage has two marks on it and it says start, and thats where the linkage acuator sits on the cam is in between those marks at neutral. Is there a test that you can do to see if the coild is leaking spark and if so how is it done. I would not be suprised if the coils and power pack are original. What is the estimated life time of coils or is it if you take care of the motor and dont run it hot it souldnt be somthing you have to worry about. Could it be a fouled plug and if so since they are pretty new what would cause such fast carb build up? Has anybody used this sea foam stuff? Does it work and do you use it as a one time treatment or every time you fill the tank up?

 

[tashasdaddy]

Re: Hesitation at WOT 82 johnson 70hp J70ELCNB

carbs can be cleaned to day, and clogged tomorrow. sediment in tank. curd in hose breaking off. a little speck you missed. coils and power packs are totally unpredictable. seafoam is great for a decarbing, also great as a fuel additive, as it keeps clean carbs clean, from varnishing. not crud in the gas thou.

 

[Evinrude Trouble]

Re: Hesitation at WOT 82 johnson 70hp J70ELCNB

is ther any way you can test your coils or powerpack with a multi meter to see if they are still good? Is the alarm in the control box themostatically controled? Is there anything else i can do to try and get top end out of my motor? I got ahold of a tach today, does anybody know what the WOT RPM's are for this motor idle RPM's?

 

[Evinrude Trouble]

Re: Hesitation at WOT 82 johnson 70hp J70ELCNB

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