1987 johnson 70hp bogging out

[thepikeman]

i just got a 1987 johnson 70 hp and it idles starts and runs slow great but when i go to full throttle it starts to bog out so i hit the choke a bunch of times and it runs fine after that. i need some help

 

[Big Bubba]

Re: 1987 johnson 70hp bogging out

The Pike Man,
Yes, sounds like you need to go threw your carbs pretty thouroughly. I would clean out all 3 of your jets remove them to do this and clean and blow out all passages that those jets go into paying close attention to your high speed jets that reside in the center bottom of your float bowls or float chambers they call it on the parts break down and after the carbs have been gone through and new kits with new gaskets installed I would do a linc and synchraonization verification in accordance with the service manual. Let us know how it goes. Thanks, Bob

 

[Big Bubba]

Re: 1987 johnson 70hp bogging out

One more thing since this motor is new to you. I would remove the old fuel, flush the fuel tank out put fresh oil/fuel mixture in it and then change out the water pump impellar at the least or replace with a whole complete water pump kit so you don't take a change of burning your outbaord up with a bad or detoriating water pump impellar not cooling your motor down. Let us know how you make out. Thanks, Bob

 

[Boss Hawg]

Re: 1987 johnson 70hp bogging out

Had the same motor & same problem not long ago-
Take the above advice -
PLUS do a compression check & spark check!
If thats OK & you do whats already been advised throw some Champion plugs in her & try it out