Hi, I bought a pontoon with a Honda BF40A outboard last Oct. It started right up and purred like a kitten before I bought it. Now, this spring, after indoor storage, it is hard to start and runs rough when it does start. A former owner said it was a 2010, but the emissions sticker says it was built to 2008 standards.

The previous owner had paperwork from a shop from last August that showed he had replaced the plugs, but complained starting issues continued. The shop cleaned the carbs with repair kit and synched the carbs. The bill for that labor and parts was about $1000. Parts listed were valve set, gasket sets, gaskets, and a jet set.

I have done the following:

-Replaced the tank with fresh gas

-Checked the fuel filter

-Checked the fuel pump

-Checked the plugs (clean and properly gapped)

-Confirmed all plugs are getting a spark

Also, I sprayed carb cleaner in the carbs. This always gets it to start, but sometime it runs only long enough to burn out the carb cleaner, then it dies. Sometimes it will run longer, so I assume it is then burning gas. When I try to start it again without the carb cleaner, sometimes it will start, sometimes not. It does not matter if I try restart it right away or if I wait overnight.

I pulled the spark plug wires off one at a time when it was running on the gas. With plugs 1 and 2, there is no change to the sound when the wires were removed. When I pulled the wire from plug 3 (with 1 and 2 reconnected), the engine kills.

After running it several times with and without the carb cleaner (yes, sometimes it will start right up without the help of the carb cleaner), I checked the plugs again. Plugs 1 and 2 were heavily fouled. Plug 3 was lightly fouled. I also rechecked the gaps. They were in the range listed in the owners manual.

Friendly suggestions would be much appreciated.

 

Clean the carburetor