outboard engine problems

[rmilavsky]

I have a 1988 Oday 240. I believe the boat displaces 3600 pounds. My outboard is a mercury 6 with a 4 stroke.
I believe it is a short length shaft attached to an aux bracket.
The motor is fine when the water is relatively calm and it can move the boat niceley.
However, when the wind starts blowing and I get some rough bay water, the boat will start to really bounce. And as the boat bounces, it causes havoc with the engine...the engine and props starts to rise....and I really struggle to move forward.
Also as the boat bounces, it causes the outboard to swivel which causes control problems.
When I motor when the wind kicks up over 15 mph , I virtually have to stand at the back of the boat, hold the control handle on the outboard in place so it doesn't swivel....and as the boat bounces, the engine makes a noise and rises...and I get no push.
Suggestions? Do I need a longer shaft ourboard? an engine with more power? Please let me know.
thanks
Ray

 

[RECESS]

An 8 hp long shaft would probably be a better fit for your boat if you are on water that gets that rough. Long shaft 20" or even better an ultra long 25". I have a 20" long shaft 10hp on my Oday 25 and still experience windmilling, prop out of the water when the stern rises up over a wave or swell. The side to side movement should be addressed by tightening a mechanism on the shaft. I have a hard time finding the ballance to be able to turn the outboard when bringing it in tight quarters like the marina slip and still having it tight enough to hold true when motoring in some chop.

I just bought a 25" ultra long shaft and hopefully it will do better when it is rough and I have to motor.

 

[rmilavsky]

Dave
Thanks for the advise. You are confirming what I suspected. I hadn't considered the ultra long shaft. I have read there are some disadvantes of getting a shaft too long....and either an 8 hp or 9.9. I do like my Mercury, but it is intolerable when I get chop- which is often.

 

[jpallen01]

I just sold my Oday 240 this spring. I had an extra long shaft (25") Evinrude 9.9HP Yachtwin outboard. It worked very well for this boat. However, I would still get the outboard coming out of the water in rough seas on occasion. I sailed on a river so rough seas for me was power boat wake mostly. And the cavitation is just the nature of an outboard on the very aft of the boat. With an outboard rudder, I would think as long as your outboard shaft isn't below your rudder that shouldn't be a problem with it being too long. If you can power up through the chop it will help. Definitely tighten up the outboard so it doesn't swivel as much as you can. Great boat. I miss it on occasion.

 

[rmilavsky]

John,
Thanks for your thoughts. I assume you sailed on the Delaware. I live in NJ and sail on the Barnegat Bay. Many an afternoon the wind really kicks up. I have struggled with this engine off and on for a few years. When the Barnegat Bay is "fairly" calm, I love my Mercury 6. But, on days when I am out a few miles on the Bay, and the wind picks up over 15, and I have to return through heavy chop....look out.
I wasn't thinking 25"....I was thinking more around 20"...but I should revisit this and probably an outboard about the size of yours.
Will definitely look into the adjustment to stop the engine from swiveling every time it hits chop and drops down.

 

[Scott On Eagles Wings]

You can most likely get a kit to extend your existing outboard to 25". If the motor is good check that out first.