1969 3 cyl 70hp Johnson

[markdenoyer]

Model# J70ELCDC<br /><br />I have little power out on the water. It seems as if my outboard is running on 2 cyls. The engine will run fine in the driveway but not on the water.<br /> Ignition: I have spark on all three spark plugs. <br /> Fuel: I have sprayed down the throats of the carbs and they seem to be clean. They were clean before I started. I have a water seperator/fuel filter just off of the inboard tank as well as a new filter on the power head itself. <br /> I closed off the top carb with a piece of cardboard as the engine was running and it stalled. Then I placed the cardboard over the lower carb the engine stalled. But when I closed off the middle carb the engine kept running. When I removed the cardboard from the middle carb fuel flowed Out the front of it.<br /> Could it be that the reed block behind the middle carb is stuck open? If the reed block is stuck open can you have a cylinder pressure? I am going to do a pressure check tomarrow when I buy the tool on the way home from work.<br /> Any suggestions all? Thank you.

 

[marinegrh]

Re: 1969 3 cyl 70hp Johnson

COMPRESSION AND SPARK IS WHERE ID START, PULL OUT YOUR JETS ON THOSE CARBS ALSO, #2 #1 ARE EASY, # 3 TAKES A SPECIAL TOOL OR A SMALL SCREWDRIVER THAT WILL GET BETWEEN THE LOWER COWL AND CARB, EVEN BETTER, PULL THE CARBS, DOESNT TAKE THAT LONG, AND YOU CAN CHECK THE BOWLS AND JETS THEN, HEY WHILE THE CARBS ARE OFF, TAKE A FLASHLIGHT AND LOOK INTO THE REED PLATES AND SEE IF THE ARE BROKEN OR ONE IS HELD OPEN, TRY RUNNING THE ENGINE THEN IF THAT DOESNT HELP WIDE OPEN WITH YOUR CARDBOARD KINDA LIKE CHOKING IT AND SEE IF IT PICKS UP POWER, THATL TELL YA IF ITS CARBS OR POSSIBLY ANOTHER PROBLEM MASKING ITSELF<br /><br />GOOD LUCK,

 

[Mod2]

Re: 1969 3 cyl 70hp Johnson

Marinegrh....I know it sounds dumb...but...please type in lower case. The upper case sounds like you are shouting. Thanks.

 

[harley909]

Re: 1969 3 cyl 70hp Johnson

I would bet on a plugged jet in the middle carb for sure. Pull it off, clean it out and pay real close attention to the main jet in the bowl. I have seen clear silicone stuck in one which created all kinds of grief until it was found.

 

[OBJ]

Re: 1969 3 cyl 70hp Johnson

DeNo....From the test you did with the cardboard, I would think that the middle carb has a float problem or the needle is worn out and not seating. If you don't know how long it's been since the carbs have been over hauled, it would be a good idea to do so on each carb.<br /><br />As far as damaged reeds, if the carbs aren't blowing back at idle speeds, I would think you are OK on that issue.<br /><br />Do keep us posted. Thanks.

 

[Solittle]

Re: 1969 3 cyl 70hp Johnson

See:<br /><br /> http://www.outboardrepairs.com/carburetors/

 

[markdenoyer]

Re: 1969 3 cyl 70hp Johnson

Hello all. I did the compression test this afternoon. I guess I should have done that before I posted a carb/reed block question. <br /><br />Top Cyl 60psi<br />Mid Cyl 0psi That is correct 0psi!<br />Bottom Cyl 40psi<br /><br />So now I have two more questions. Where is the best place for powerhead rebuild in Mich?<br />Also.. how the HECK was this thing running at all!!

 

[marinegrh]

Re: 1969 3 cyl 70hp Johnson

sorry to hear the big 0 on #2, good luck <br /><br />fair winds and following seas