Hi,<br />I have a 1996 Yamaha 115 BETOL V4.<br />After browsing lots of related topics posted on this site I am more and more convinced my engine suffers from a "lean burn" and/or a dirty carburettors. Spark plugs changed and look OK, have run it on fresh gas from a separate tank with no change in behavior. Last thing I did was to try to rinse the carbs by opening the drain screws (it has two two-port carbs that looks pretty symmetric from outside so I guess there's separate "floaters" for each port).<br /><br />The engine works completely OK at speed, but getting into dock with other boats around is like begging for a heart attack. After the rinsing I feel it might be a bit better when it's cold, but when warm it's the same as before. When warm it might also be hard to start again even if I raise the throttle - found it to work better if I use the choke(!), which to me points even more in the direction of a "gas-related" problem.<br /><br />I would appreciate some advice that I can try with the boat still in the water (i.e. possible to reach from the front, no special tools, low risk for dropping screws into the sea etc). <br /><br />Would like to try having less lean mixture at idle speed but I am no expert and it has to be "safe and simple" for now. I can spot one adjustable screw for each port (on the top/side and relatively close to the block) but don't know if they're for high speed or idle. Can somebody tell based on this vague description or else tell me where and how to adjust the mixture?<br /><br />I am also prepared to try to add something to the gas but would like to get a suggestion of what to use.<br /><br />Thanks in advance!
