1982 johnson 70 hp WOT problem.

JimeeB

Cadet
Joined
May 25, 2011
Messages
24
Ok guys here is the issue and steps I have already taken.

1st the issue...
When doing a lake test idling out of the no wake, the motor preforms flawlessly, as soon as I start to throw the coals to it it loses power and will eventually die if I stay in the throttle. I can push in on the key switch and activate the primer and the motor will pick up and run ,however it does not run as it should. The rpms seem to be ok but it just does not seem to have the power it should. Also it tends to want to slow down over time and again activating the primer will bring it back around.

Steps that have been taken are as follows.
All steps taken from my Clymer manual.
Timing set to 19 deg BTDC
Carbs taken apart and cleaned (and they looked quite nice for sitting all winter)
New oil/fuel mixture.
Compression checked good.
good spark at all three plugs.
Synchronized carbs cam and follower.
No overheating water pump was changed also

Now on some other posts I have read here, people state to run at WOT and pump the primer bulb to see if that has any effect, I have not done this yet as I am the only person on the boat and I dont really want to leave the helm and go to the back of the boat. I am sure you understand why..

So am I dropping a cylinder at WOT??? When I'm on the water it really does not sound like a miss, rather just very
sluggish'
And as I said If I try to go WOT and keep it there without doing anything else she will fall flat on her face and die.
I didnt mention the prop pitch because I am 99.9 % sure that its not the prop. And to be quite honest I forget what pitch it is right off hand.

Any suggestions???
Thanks.
JimeeB
Oh, and if it matters this engine is mounted to a 22 ft pontoon.
 

retiredfornow

Petty Officer 1st Class
Joined
May 9, 2011
Messages
355
Re: 1982 johnson 70 hp WOT problem.

Is that motor new to the pontoon, or did it run good before, like last fall? In other words, when did this start happening.
 

JimeeB

Cadet
Joined
May 25, 2011
Messages
24
Re: 1982 johnson 70 hp WOT problem.

Is that motor new to the pontoon, or did it run good before, like last fall? In other words, when did this start happening.
No the motor is not new to the boat and it ran fine 2 seasons ago. Last season we had problems with the gearcase and got all of that worked out but the boat never really went out on the lake. Prior to that it ran like a dream.
Been scratching my head on this one. 2 morrow I am taking the fuel pump off and inspecting it I suspect the diaphragm is probably wore to the point that it just wont deliver enough fuel for WOT operation. I hope thats it coz I really dont want to shell out the extra $$ for a new power pack.
But I suppose you asked your question for a reason, so what were you thinking it may be????
 
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