New to Us Islander, what Props are you Running, Twin F150's

[Andrew93]

Well I sold my 1999 272 Sailfish this spring due to a newborn and figured it would not get too much use. I planned on just using my fathers 180 Sportsman for a few years until I would upgrade to a newer Sailfish or Marlin. We did not remain boatels as long as we anticipated, we came across a deal we couldn't pass up. Although we were leaning towards a Gulfstream for our "temporary" boat until the newer Sailfish or Marlin, we found a 1997 268 Islander with twin 2007 F150's, my father was very excited about this one and between he two of us hopefully she will get a lot of use.

We bought it knowing it was going to need a few things. When we were bringing her home by water we noticed the RPM's were only getting to 5000 and 4700. I plan on sending out the injectors and going through the fuel system, but I was wondering what props people are running on this setup. It currently has 13.75x19's, I figured it would have 17p props on it. I just ordered the YDS cables, I have had a lot of OX66's but fairly new to the Yamaha 4 strokes.

Below is a photo, the name would be great is we had a pug, but we are leaning towards "Just for Now"

Thanks

Andrew

 

[Hookup1]

I have been running a 268 Islander with twin Yamaha f-150's with 17 x 14 1/4 3-blade Yamaha Reliance stainless.

Generally the boat is a 10 knot or 20 knot boat with no in-between. I want to improve my low end performance so I can plane at lower speed. I have plenty of top end and can only use it on the best of days.

I spoke to Ken at propgods.com and he recommended swap for 15 x 14 4-blade. Thinks my low speed performance would significantly improve and maybe even my top end speed.

Propgods.com recommended these…

https://propgods.com/shop/ols/products/ptz4 (on order)
or these
https://propgods.com/shop/ols/products/ptz3 (similar to Yamaha Reliance)

 

[Andrew93]

Great, thanks for the info. This boat has 13.75 x 19P and I think it is over propped. The one good run we had on it we barely got 5000rpm's. Also I discovered some corrosion problems on both motors, one with an exhaust leak, I posted some photos in another post. I am getting ready to pull the powerhead and will update it with more pictures. I guess it is rare in the F150's but a common reason is the boat being over propped and the exhaust gases running hot that causes the corrosion.

With this year hull without the extended running surface I bet the 4 blade props will be a big help, I'll keep my eyes open for a pair over the winter before I bite the bullet on a new set.

Thanks

Andrew

 

[Hookup1]

Great, thanks for the info. This boat has 13.75 x 19P and I think it is over propped. The one good run we had on it we barely got 5000rpm's. Also I discovered some corrosion problems on both motors, one with an exhaust leak, I posted some photos in another post. I am getting ready to pull the powerhead and will update it with more pictures. I guess it is rare in the F150's but a common reason is the boat being over propped and the exhaust gases running hot that causes the corrosion.

With this year hull without the extended running surface I bet the 4 blade props will be a big help, I'll keep my eyes open for a pair over the winter before I bite the bullet on a new set.

Thanks

Andrew

I'll let you know how we make out. Boat in FL for February - Covid willing!

 

[efx]

I have the same boat, a 1999 with twin 2017 150s.

I am trying out the powertech OFS3 15.25 x16

These have been recommended by a experienced owner of the islander.

Ill report back once i get the boat out more.

 

[Hookup1]

I have been running a 268 Islander with twin Yamaha f-150's with 17 x 14 1/4 3-blade Yamaha Reliance stainless.

Generally the boat is a 10 knot or 20 knot boat with no in-between. I want to improve my low end performance so I can plane at lower speed. I have plenty of top end and can only use it on the best of days.

I spoke to Ken at propgods.com and he recommended swap for 15 x 14 4-blade. Thinks my low speed performance would significantly improve and maybe even my top end speed.

Propgods.com recommended these…

https://propgods.com/shop/ols/products/ptz4 (on order)
or these
https://propgods.com/shop/ols/products/ptz3 (similar to Yamaha Reliance)

View attachment 17042

So I've had my chance to test these props in the Florida Keys this winter. For my 1997 268 Islander w/twin F150's they are absolutely perfect. Dropped 2" of pitch, 1/4" of diameter and changed to a different style prop (vs Yamaha Reliance). Significant - unbelievable improvement in low and mid range performance. Boat will plow and plane at lower speeds that could not be done before. Top end unaffected. In rough seas motors don't bog down and "grip" better to keep boat from falling off. Highly recommend.

A lot of boaters think dropping pitch will slow the boat down. Not always true. If over propped and "slipping" its too much load on the engines. Prop correctly and increase efficiency.

 

[family affair]

Don't leave us hanging. Give us some numbers!

 

[Hookup1]

I have been planning to write them down but its been so windy and rough. I'll do it this week. For me though it's more about how the boat feels in different sea conditions.

For example running in with a following sea was always a problem. You push the throttles up to a speed to match the waves behind you. Run along for a short while and the boat gets some air under it and runs away at 20 knots. It then crashes into a wave in front of the boat, boggs down the engines and you are back at 10 knots. Much different now. You can pick a speed either plowing or planning and the engines will hold RPM's. It's a easier ride instead of getting slammed around.

Also I ran offshore in a head sea. Easier to dial in a speed and the level of abuse you want to take. Holds RPM's much better.

I have run the motors up a few times when conditions permitted. The cruise and top end are still there. I'll get numbers up this week.

 

[Hookup1]

So here are the raw numbers from a Florida Bay run by Channel 5 East to West and reversed. Blowing 20 knots ESE. 150 gallons of fuel and 2 people on board. 15 gallon bait well with water on transom step. Lots of gear on boat.



Higher end performance is right in there with the old props. Low end performance much better. You could not plane at 3,400 RPM's. 3,900 RPM's is was problematic.

10/15/2021 Update - WOT 5,500 RPM's 34.4 knots.

 

[Andrew93]

Thanks for the follow up. Turns out I was not reaching top RPM's most likely due to low compression and massive corrosion in both powerheads. Due to the cost of replacing both powerheads ($15k+) and being too afraid to tackle it myself we repowered with new to us 150hp HPDI's.

I have 2 sets of props to try, the 13.75x19's that was on the F150's and 15.25x17's that came on the HPDI's. They were on a 2003 25' aquasport CC, so I think trying those first would be the best bet, but we will see. Hopefully uncover the boat in a week or two and start buttoning up the new motors. They were hung and started, but still some work to do.

 

[Hookup1]

I installed new props this Winter in prep for my Florida trip in February.

https://propgods.com/shop/ols/products/ptz4 (bought these) 15 x 14 4-blade.

 

[Mark DV]

Let us know the new numbers when you have them.

 

[Hookup1]

See above...

 

[Mark DV]

Ok thanks. Did your WOT RPMS improve?

 

[Hookup1]

Redline is 5,000 RPM's and 30 knots. I never run above 4,800 RPM's and 28 knots. Both numbers were the same as before.