97 johnson 70hp miss at ldle

[eggbert55]

Rebuilt carbs on 96 70hp but still has a miss at idle in gear.... adjusted low speed jets at idle while in gear but top carb doesn't adjust, meaning I can turn the srew all the way in to seat and rpms never change the other 2 cylinders will cough and die when mixture gets to lean.... have checked compression 125 in all cylinders, changed plugs, checked for spark good on all cylinders.... what could be wrong inside that carb or is there something else I'm missing?????

I rebuilt the carbs because it had become very difficult to start when cold but ran and idled fine once it was warm... now it starts right up but has the miss and will often die at idle in gear which is very frustrating when tring to get in or out of slip (pontoon boat).....

 

[racerone]

Re: 97 johnson 70hp miss at ldle

Did you find anything wrong in the carburetors when they were apart?---Was the high speed jets removed from the bowls for cleaning ?-Did you check the reed valves when carburetors were off.

 

[eggbert55]

Re: 97 johnson 70hp miss at ldle

Only found oily residue... cleaned carbs, did not remove high speed jet just used a fine wire to make sure passage was clear and installed kit.... did not check reed valves as the engine ran fine before rebuilt was just hard to start after it would sit for several weeks without being ran.... everyone told me this was a common problem for this engine and to rebuilt carbs.... starts easy and runs fine except for the idle problem now.

 

[racerone]

Re: 97 johnson 70hp miss at ldle

I would revisit the top carburetor.----Remove high speed jet that screws into the float bowl to make sure it is clean.------Remove plug on carburetor bowl.-Squeeze primer ball. Does fuel pour out of the bowl ?

 

[eggbert55]

Re: 97 johnson 70hp miss at ldle

I'll give it a try but will be a few weeks before I get to the lake it's 80 miles away... thanks for the help