225 Yamaha - HELP!

[harrellusa]

Just installed 89 225 Yamaha. Everything works fine except that when the engine reaches WOT, engine RPM falls off drastically after only couple of seconds. Dealer has checked fuel pressure, plugs and 02 sensor. Anyone ever have this problem?

 

[Terry Harper]

Re: 225 Yamaha - HELP!

Does your motor have an anti knock sensor. It is a black hexagonal device with 1 screw in the centre located inboard on the stbd head. Its job is to retard the timing should the engine start to knock or ping.

 

[MIKENVAHBEACH]

Re: 225 Yamaha - HELP!

Harrelusa- I have the same motor and had the same problem earlier this year. I needed the fuel pumps replaced. If one goes bad, it will pump enough fuel to keep you running, but as soon as you go WOT you empty the carbs and she will drop RPM's and fall off plane. Its an easy fix, Norfolk Marine stocks the parts, replace both pumps, it will take you 30 min or less. Hope this helps you. Good Luck. Let me know how you do? Love to find someone close by with the same motor?