Newbie to IOs

[T Pink]

Bought a boat with an IO last fall (18ft Spectrum with 3.0 Mercruiser). I've had a couple of boats prior, but they were outboards. I'm not clear on the point which you souldn't tilt above and give it much power (if any) like in shallow areas / at the lake access...with outboards this is not a concern.<br /><br />I think i hear kind of a whine at full blast (5600 RPM?), and kind of a vibration when turn full left and full right.<br /><br />Did I damage something from tilting too high (slow / shallow / boat ramp situations)? Or, is this just normal maintenance (pull outdrive and grease u-joints)?

 

[GregCC167Concept]

Re: Newbie to IOs

Are you sure you should be turning that kind of RPM? Have you checked the specs? If not, that could be why you hear whining. You need to be trimmed down enough to get water in the intakes - period. Make sure when you are trimmed up, the cavitation isn't moving to much water away from the intakes.

 

[Trent]

Re: Newbie to IOs

That engines range is 4200-4600 RPM. Dont over rev it or you will be sorry! Dont go over idle speed when the drive is up past the trim limit switch (drive up more than trim range...about 10-15 degrees from full down). You can damage the u-joints.

 

[T Pink]

Re: Newbie to IOs

Ok so maybe it's 4600RPM? Do the u-joints need to be greased on a regular basis?

 

[C17LoadSmasher]

Re: Newbie to IOs

5600 RPM! ACK! Redline on the 3.0L is 4800, I try to never exceed 4500. If you tend to run into many shallow areas, I suggest a paddle :-D They're cheaper to replace than the outdrive. A paddle is also good to have anyways.

 

[mlslocks]

Re: Newbie to IOs

Yes the u-joints should be greased and while your at it you can inspect or replace the gimble bearing.

 

[Doug Durako]

Re: Newbie to IOs

Is the whining noise coming from low in the drive? Could be an out-of-balance prop. Borrow a prop same size as yours (dia. and pitch should be marked/stamped on the prop) from a friend with your same drive unit and see if the noise goew away.