Prop Help
 

I recently bought a 1987 Rinker 250 with Mercruiser Alpha One 260 (5.7
liter). There are no markings on the existing prop, but it appears to
be almost a flat prop - no cupping. The performance is poor, but WOT
is about 5500 RPM. Looking for suggestions for a new proip, or at
least a starting point. I don't want to spend thousands of dollars to
dial it in.

Prop Help
 

sounds like it's right, 5500 is w/in range for a 350, isn't it?



On Sun, 22 Jul 2007 14:11:32 -0700, fireguy wrote:

I recently bought a 1987 Rinker 250 with Mercruiser Alpha One 260 (5.7
liter). There are no markings on the existing prop, but it appears to
be almost a flat prop - no cupping. The performance is poor, but WOT
is about 5500 RPM. Looking for suggestions for a new proip, or at
least a starting point. I don't want to spend thousands of dollars to
dial it in.

Prop Help
 

On Sun, 22 Jul 2007 14:11:32 -0700, fireguy
wrote:

I recently bought a 1987 Rinker 250 with Mercruiser Alpha One 260 (5.7
liter). There are no markings on the existing prop, but it appears to
be almost a flat prop - no cupping. The performance is poor, but WOT
is about 5500 RPM. Looking for suggestions for a new proip, or at
least a starting point. I don't want to spend thousands of dollars to
dial it in.

Clean the inside of the prop of exhaust residue and the size and pitch
will be stamped where the prop hub meets the shaft spline.

I think you might want to drop the rpms a little - that seems awful
high for a 350.

Prop Help
 

On Jul 22, 5:33 pm, Josh Assing wrote:
sounds like it's right, 5500 is w/in range for a 350, isn't it?



On Sun, 22 Jul 2007 14:11:32 -0700, fireguy wrote:
I recently bought a 1987 Rinker 250 with Mercruiser Alpha One 260 (5.7
liter). There are no markings on the existing prop, but it appears to
be almost a flat prop - no cupping. The performance is poor, but WOT
is about 5500 RPM. Looking for suggestions for a new proip, or at
least a starting point. I don't want to spend thousands of dollars to
dial it in.- Hide quoted text -

- Show quoted text -

If I remember correctly, I think that wide open should be more like
4400 RPM's.

Prop Help
 

On Mon, 23 Jul 2007 09:21:21 -0700, Capt John
wrote:

I recently bought a 1987 Rinker 250 with Mercruiser Alpha One 260 (5.7
liter). There are no markings on the existing prop, but it appears to
be almost a flat prop - no cupping. The performance is poor, but WOT
is about 5500 RPM. Looking for suggestions for a new proip, or at
least a starting point. I don't want to spend thousands of dollars to
dial it in.- Hide quoted text -

- Show quoted text -

If I remember correctly, I think that wide open should be more like
4400 RPM's.

Yes, 4400 to 4500 is about right. I used to have the same engine in a
comparable boat. It had a 15 x 17 prop which was OK when I bought it,
a 14 1/2 x 17 was even better.