Weird Yamaha 225 problem

[wannafly]

I have yamaha 225 saltwater series outboard on my 23 seacraft. Runs great on smooth water but if I hit a wave or go up a swell I lose Power for a split second lose rpms and then kick in again. other wise engine runs great at any rpm. Plugs are new check electric connection and all is fine. Also experienc problom when coming out of the hole. Seems to occur more frequently as boat runs more. Any thoughts thanks carlos

 

[andrewmac]

Re: Weird Yamaha 225 problem

Wannafly,

It sounds like the problem may not be with engine, but possibly with the propeller, engine height, or too much trim. Is this a new problem? Has the engine previously run good before?

If the propeller has too much pitch or is damaged it could cavitate, especially when under increased load. If the hub is beginning to spin it would happen under the same circumstances. Sometimes you can smell a spun hub by smelling for burnt rubber when the boat is out of the water.

If the engine is mounted too high you will see the same symptoms, especially when traveling in heavy seas, but most often in a following sea. The anti-ventilation plate should be even with the bottom of the boat +/- 1 inch.

Too much trim does the same thing as the engine being mounted too high. Make sure you are trimmed all the way down when testing.

Good luck!

 

[wannafly]

Re: Weird Yamaha 225 problem

Engine ran perfect all summer and I have not changed trim or engine height.
I will check prop thanks all suggestions welcome carlos

 

[Captn Dave]

Re: Weird Yamaha 225 problem

andrewmac,

The causes you are mentioning will cause an increase in RPM, not a loss as he's describing.

 

[scjmc]

Re: Weird Yamaha 225 problem

It could be the VST filter. When mine was dirty the first indication I had was a loss in RPMs after hitting a big wake. Whats differant though is that I had to turn the motor off, and restart it before it would behave normally.

 

[ARCHSEA BUNKER]

Re: Weird Yamaha 225 problem

its your vst filter remove the 10 small screws drop the metal cover , unscrew the filter , soak in carb cleaner , blow clean if you have air jet, reasemble , hold rubber o ring in place with vasoline, if o ring has swelled to much place in ice box for one hour 'been there done that'