Yamaha Motors - Prop spins while in neutral

Question for our resident mechanics or knowledgeable Yamaha guys or gals on the site, I have an question. I own a 2001 Grady White Islander with twin 200 Yamaha HPDI outboards. Bought the boat used in 2010, motors had `300 hours on them, counter rotating. The port motor since we purchased the boat has turbulence at idle, starboard motor does not. While in neutral and giving it no throttle, the prop on the port motor spins causing turbulence. You can actually see the prop spinning even though the gauges are showing zero RPM's. It doesn't appear to cause any performance issues but I'm not sure why the prop would spins when in neutral. It only happens with the port motor, not both.

Anyone have any guesses what might be causing this, never seen it on any other boats I've owned. As I said, it doesn't seem to effect performance but would like to know what's causing it and make sure it doesn't effect performance at a later date.

Appreciate anyone who might have some insight.

Thanks!

[Duffman]

On the hose or in the drink?

While the motors are down and in the water. Gears are in neutral but port prop spins to an extent where it causes surface turbulence.

[Duffman]

Not an expert at all so hope others will chime in but IMO that isn't right.

On the hose the prop(s) will spin due to water pressure. Under water, the pressure should keep them from turning, or turning very little.

If your pushing water around while in nuetral while at the the dock, I'd look at your shift linkage adjustment.

[Capt. Debbie]

Try something... Put port side engine in gear and see if it'll start in gear. If so, it been tampered with.

I suspect, if test works that the engine's shifting linkage are askew and someone by-passed the In-gear lock out that would prevent the test I suggest from starting that motor.

Also if the starboard side O/B is not running.... are effects different?

Originally Posted by Duffman

Not an expert at all so hope others will chime in but IMO that isn't right.

On the hose the prop(s) will spin due to water pressure. Under water, the pressure should keep them from turning, or turning very little.

If your pushing water around while in nuetral while at the the dock, I'd look at your shift linkage adjustment.

Capt. Frank, will try your suggesting this weekend and let you know how it works out.....thanks

Capt. Frank,

As you suggested we tried starting both motors while in gear and neither motor would start so it appears the shift linkage is not the issue. Anyone else's thoughts would be appreciated. Again it doesn't appear there's any performance issues associated with this matter but it's an annoyance seeing the water bubble in back of the one motor while the motor is in neutral.

Dakota

[hammer4reel]

Originally Posted by dakota560

Capt. Frank,

As you suggested we tried starting both motors while in gear and neither motor would start so it appears the shift linkage is not the issue. Anyone else's thoughts would be appreciated. Again it doesn't appear there's any performance issues associated with this matter but it's an annoyance seeing the water bubble in back of the one motor while the motor is in neutral.

Dakota

what is your tach idle on both engines ??
I believe IF your idle adjustment is set too high, it can cause your prob to spin, as well as make it a little tougher to slide into gear.
That can happen by the adjustment screw moving as well as the AIC valve getting getting carboned up, or starting to stick

Dan about 600 / 700. Will check the manual to see what it should be but it's the same on both motors and as mentioned only one motor has the turbulence.