Alpha one exhaust question

[Chopper Doc]

Ok, I am sure this is a dumb question for you guys but since I don't know the answer to it I don't know if I may have a possible problem. Here goes. First off I have a 2005 Tahoe Q4 Sport. It has a 3.0L Mercruiser Inbd/Otbd with an Alpha One drive. It has a 14 1/4 x 21 inch prop and runs roughly 43.9 mph at WOT at 4900 RPM with just me in the boat. Under a standard load it turns around 4800 +/- 100 at 42 MPH. I am fairly happy with this as I normally do not tow skiers. Gets good fuel usage as far as I can tell too. My question is this. I know it has a flow through prop for the exhaust but at idle with the outdrive lowered the exhaust seems to come out around the gimbal rings. Is this normal? If I run the engine with the water hose hooked up to it I notice that hot water comes out from a hole on the right side of the gimbal ring while some exhaust and water will also come out of the prop and the left hole in the gimbal ring. Is this right for my outdrive or is something broken?<br /><br />Thanks,<br /><br />Wes

 

[Reel Poor]

Re: Alpha one exhaust question

There is no problem there. Those hole are pressure relief holes and are necessary for low speed and idle situations.

 

[ntheyer]

Re: Alpha one exhaust question

Everything sounds normal to me.

 

[Chopper Doc]

Re: Alpha one exhaust question

OK, thanks a lot guys. That really takes a load off my mind. I was thinking I was having a problem. I have went from a really small fishing boat to this bigger boat and I have made some mistakes with it already. My main problem is I have a hard time remembering to trim the outdrive completely up when I trailer the boat. So as you can guess it is new boat with a beat up skeg. I have also busted one propeller already. I was backing out of a dock at a boat ramp and a peice of debris got stirred up somehow and managed to wedge between the prop and the cav plate. I believe it was a cypress limb. Anyway the prop hub should've given way but instead it bent the prop tips and broke one tip off. Thankfully I was at the ramp. I haven't completely gotten used to how deep this thing rides in the water. In 2 feet of water I have to trim the outdrive up a lot or I will be churning the bottom. That is at a slow idle to boot. Maybe it'll eventually sink in <br /><br />Thanks again,<br /><br />Wes

 

[Doug Durako]

Re: Alpha one exhaust question

Chopper---launching and getting back on the trailer have certainly killed many I/O props and skegs! Your specs on the boat should tell you the exact "draft"---how much water it takes to float the hull. Just remember your lower drive is below that draft line, and you could get a depth finder to sound an alarm at that depth.<br /><br />The other thing I do is always check with a couple of locals at a boat ramp if I have never launched there to see where the deepest water is. Or, you can wade in before you back the boat all the way down.<br /><br />This makes the locals feels smart. You would be surprised at people who are just standing around waiting for boaters to hit stuff. Just so they can yell "I could have told you not to put your boat in there."