weak spark & sniffle ? 1989 Johnson gt150

[KKNOPP26]

Hey all,
Have a 1989 johnson gt150 i have been restoring. Finally got time to put it in the water today but the motor struggles to stay idling and intermittently will sniffle/sneaze. Tho its starts easily and can keep it on by bumping the throttle to 1200ish, the motor wont idle down and stay running for more than 30 seconds.

I got home, pulled and cleaned the spark plugs and found each cylinder has spark. touched each to the block while having others grounded and water running via muffs.

Are these the same issue(weak spark and sniffling/not wanting to idle) ? and where should i start looking ?

Thanks!

have new gas (50:1), new filter, fuel pumps, and a carb rebuild all less than 3 weeks ago, but this is the second time gas has been pushed through the motor since last sunday.

 

[Jhayes780]

Did you ever find a resolution

 

[ct1762@gmail.com]

Did you ever find a resolution

what he should've done is 1st compression test or better yet borescope cylinders. 2nd is to squirt premix from a small syringe into each carb throat at idle and see if the sneeze goes away. if it does, carbs or throttle plates open a hair or air leak. if not, its ignition. then you go on to dva cranking and running tests to be sure the ignition is ok. you can also index the flywheel to make sure all cyl are firing at the correct time.

 

[Crosbyman]

he probably did 7 years ago !!