9.9 Honda Don't run so good.

[Bmclark602]

9.9D 2002 electric start 12A Gen. with 60 hours since last service in 2008. About 300 hours since new. Ran good 3 months ago. Last week it seemed to only push the boat about ? as fast. Put in new plugs and fresh gas, cleaned filter and did an oil change yesterday and it still feels like it is missing (but runs smooth), and will not wind-out but accelerates ok but slower then normal. I pulled plug wires one at a time and it makes a deference in the sound. For the first time it backfired 2 times on the way into the dock at low RPM. Any advice would be appreciated. Thx Bill P.S. I have a service manual i bought incase i had any trouble while in Mexico with it. Never had to use it.

 

[gss036]

Re: 9.9 Honda Don't run so good.

I think you need to clean the carb. If nothing else, drain the carb bowl w/the drain screw on the bottom of the bowl. Disconnect the fuel line at the pump on the rear of the engine and put carb cleaner/Techron in the line and push it into the carb until it runs out the drain. Then, after it sits a while start the engine and see if that manages to clean the very small orifices that is in the Honda carbs.

 

[linehand]

Re: 9.9 Honda Don't run so good.

Sounds like the float needle is hung up almost closed or there is a piece of poo on the needle tip. Explains backfire at start too much fuel. and not reving out not enough fuel.
Like gss036 said blow some carb cleaner through the pilot jet and ceck the float situation.

 

[isaksp00]

Re: 9.9 Honda Don't run so good.

I have an older (about 1992 or 1993) Honda 8. I removed my carb and disassembled it (except for the throttle plate), and cleaned out the float needle area and also the pilot jet, using carb cleaner, and for the jet a very thin copper wire strand. If forcing cleaner through the hoses doesn't fix it, I assume the 9.9 carb is pretty similar, and I found it fairly easy to do (and I am not a mechanic), with the shop manuals. I'd try that as a next step.