how do i find Alpha gear ratio

[ottawamerc]

Hello

have a 1987 Sea Ray 268 with a 260 Mercruiser, It's new to me and I put a new engine in it this year. It doesn't seem to want to run WOT it has a 16X16 3 blade and a 16X?? 4 blade prop. It will only get to about 3400-3500rpm and takes a bit to get there. Under the Sea Ray web site there is a chart that says that combo should have a 1:5 upper gear set, I'm thinking it may have the wrong gears in it and I would like to check to confirm what is in there. So how could I do that with the outdrive attached? The chart also says that it should have a 15.5X15 prop, could the 16X16 cause that much RPM change?

 

[thumpar]

The only higher ratio was the 1.32 that they only put them behind the 454 for a couple years. They are rare and doubt that you would have one. You can turn the drive and watch the prop. See how many turns it takes to turn the prop once.

 

[redmen62]

Seeing as you're over 1000RPM under where you should be, it's not all prop.

Not sure on the gears with it attached , but there's a lot to check otherwise.

-How's the hull? Clean?
- carbs working right? Secondaries opening up all the way?
- good compression?
- fuel flow? Fuel filter? Lines ok?
- plugs, wires, cap?


I just went through the same type of thing. I ended up with my secondaries not opening and a new fuel filter

 

[stonyloam]

The outdrive gear ratio and serial number should be stamped on the port side of the driveshaft housing (upper).

 

[ottawamerc]

The outdrive gear ratio and serial number should be stamped on the port side of the driveshaft housing (upper).

Where would these stampings be?, I've looked all over the place for them on both of my Alpha 1s I cant find anything?

 

[Bondo]

Where would these stampings be?

Ayuh,.... Under the decal, upper aft portside,...

 

[achris]

Look in the sticky section. There's a post all about finding serial numbers. The ratio is with the serial number.

 

[ottawamerc]

Ah ok I got it thanks guys