dropping cylinders

[charlie_monkey]

Hello! I have a 1980 Johnson 85 HP that is dropping a cylinder or 2. At idle and low rpms, it seems to be running on only 3. As I increase throttle about half of the time it will kick back in at around 1/2 - 3/4 throttle. The other half of the time it won't and obviously it can't get up on plane. It's kind of a guessing game wondering if I will jump up on plane and take off or not when I put the throttle to it. I did replace the fuel filter recently with a non OEM filter. Could this be a fuel problem? Spark and compression were perfect about 3 weeks ago and it's only been run about 2 hours since.

Sorry this is so long. Thanks in advance.

-Josh in NC

 

[HybridMX6]

Re: dropping cylinders

Perhaps something is blocking the low speed jet on the carb that feeds that cylinder? Have you check the plugs to see if the one that is dropping looks all wet or not? If it's wet it's getting fuel, but no spark. If it's dry, it's not getting fuel, and also no oil for lubrication.