Break in twin F150 on 1999 268 islander

[efx]

See video of the islander running. I’m putting about two hours of run time on her a weekend trying to get up to the 20 hour mark so I can change the fluids. So far so good. 3500 rpm cruise, 25-26 mph, 10-11 gph. Everything is working out well. Engines are loosening up. Wot is going up each time I go out. 5800 right now.

 

[family affair]

Looks and sounds great!
I love the sound of twin 4 cylinders. The little I have ran mine were music to the ears!
Resealed both lower units and now I'm elbow deep in counterbalancer replacements. Hopefully this weekend I'll be on the water.

 

[Stephnic]

I have a 1998 Islander and re-powered it with F150’s last years. Great engines and good on fuel. I’m getting 43 mph at 5600 rpms

 

[efx]

Here is a snapshot of the gauges at 3500 rpm. Props are 15 x 16.25 power tech ofs3.

 

[Toothpick 10]

Very nice. What motors did you have on the Islander before these new 150s?

 

[efx]

Very nice. What motors did you have on the Islander before these new 150s?

I bought the boat used and it had the original 1998 Yamaha 200 2 strokes. Good motors but filthy and loud. I was able to sell them but they were pretty much parts motors. I was very glad to eliminate the onboard oil tanks from those two strokes. I’m pretty sure the bilge had a gallon of 2 stroke oil spilled in it. Complete mess that I am still cleaning up.

 

[Toothpick 10]

I bought the boat used and it had the original 1998 Yamaha 200 2 strokes. Good motors but filthy and loud. I was able to sell them but they were pretty much parts motors. I was very glad to eliminate the onboard oil tanks from those two strokes. I’m pretty sure the bilge had a gallon of 2 stroke oil spilled in it. Complete mess that I am still cleaning up.

I understand that you are still breaking in the 150s, but how would you compare the performance of the new 150s to the old 200s? I'm curious, why didn't you go with new four-stroke 200s?

 

[efx]

Good question about the 150s vs the 200’s. The bottom line is price and availability of the 150s. The performance difference between the 150s and the 200’s was small and would not have made a real world difference to me except more up front cost. It seems like the 150 is the deal motor out there across all brands and that there are more 150s made than other sizes. I was able to find a 150 counter rotating motor quickly. Also the 150 is a 4 cylinder that puts out 162 hp. It’s a strong 150 with more than adequate displacement. Grady whites are not fast boats so 3500-4000 rpm and 30 mph is perfect. Also it looks like I will be getting over 2 miles per gallon at cruise speed. That, to me, wins hands down since I run for hours between Southern California islands, stay the night, then fish the islands or channels between. There are trips that I will cover 200 miles over many days. Gas mileage and reliability are mandatory.

 

[family affair]

Our 248 with a 225 ox66 would at best get 2.7 mpg. Grady tests showed 3.0. The prop had been reworked and I'm sure had something to do with it.
The 270 with 150's and a decent load shows 2.4 from Grady. I thought that had to be complete BS considering 225's can't crack 2.0. If the Yamaha flow meter is accurate, I have seen a GPS verified 2.2-2.4 mpg. Impressive IMO. The props are unmolested OEM. Hopefully you will get similar results.

 

[efx]

Our 248 with a 225 ox66 would at best get 2.7 mpg. Grady tests showed 3.0. The prop had been reworked and I'm sure had something to do with it.
The 270 with 150's and a decent load shows 2.4 from Grady. I thought that had to be complete BS considering 225's can't crack 2.0. If the Yamaha flow meter is accurate, I have seen a GPS verified 2.2-2.4 mpg. Impressive IMO. The props are unmolested OEM. Hopefully you will get similar results.

From what I’m seeing right now, I should get the 2.4 mpg on calm seas. With a head sea, I expect to get half of that. There are days where I just have to plow through a sea right on the nose for some time, then everything changes and then back to it. If I average over 2.0, I will be thrilled. My tank is 128 gallons so I should have 160 miles of range using the 1/3 rule. 160 is perfect because I can hit Marina del Rey, LA harbor, Dana point, Newport or San Diego.

 

[SmokyMtnGrady]

The F150 is perhaps the best 4 stroke Yamaha has ever made. I had a 192 and it came with a 2 smoke Johnson. I remember the day I repowered with a F150 and it was a new boat. That motor was flawless for me. Congrats on the repower.

 

[Toothpick 10]

There have been several people on this board that have put twin 150s and I have not heard of one that wasn't happy. They really increase the range of that boat if you are getting over 2 mpg.

I will probably have to make the choice soon for replacement motor(s). I still have the single 250 OX66 that I'll probably keep until it blows up.

 

[efx]

Just did 35 miles last weekend. Rougher and was cruising at 3300 rpm, 24-25 mph. I’m at 10 hours now. Everything is running very well. These engines are quiet and just run. They are fine machines. Very happy.

 

[efx]

There have been several people on this board that have put twin 150s and I have not heard of one that wasn't happy. They really increase the range of that boat if you are getting over 2 mpg.

I will probably have to make the choice soon for replacement motor(s). I still have the single 250 OX66 that I'll probably keep until it blows up.

I had twin 250 ox66 on a Marlin. Great engines. The biggest difference I have found is overall noise and smoke between the ox and four stroke. It just makes the day more enjoyable and the best part is that I don’t have an oil tank mess in the boat. If you can find some left over 150’s, that’s the way to go.

 

[efx]

So the 20 hour break in is complete. They are getting better with each run. Just did the last three hours on a perfect 2’ swell at 14 sec day. Motors all the way up with power tech props. I can hit 46 mph. Very surprised with the twin 150s. Here is a video at 3500 rpm.

 

[family affair]

Just got back 30 minutes ago from our outing. Same sight and sound with our 150's! We get the same top end speed also.
We are running the factory Yamaha props. I'm wondering if you get any prop chatter or ventilation if you don't have the engines trimmed down to the bottom 1/4 of the trim range? I know the 99 doesn't have the full running surface, but curious if powertechs do the same thing regardless.

 

[efx]

I do run them all the way down for the hole shot then trim them from one bar to four bars on the trim meters. Tabs are flat. I can hit 6000 rpm at this setting. I don’t have cavitation or excessive prop slip. I’ve had Solas, Michigan, enertia and Yamaha props. I think the power tech have a really fine tuned turned up edge that keeps them sticky. The cylinder also turns out like it’s been flared and it’s very long. It feels like an enertia but slightly less aggressive. The enertia really shine on etecs. I’m very happy with power tech. Let’s hope a blade doesn’t break off…. That’s another story.

 

[family affair]

Looks like you have them dialed in nicely. Do you have the engines set at neutral or are they toed in or out?

Today is the 1st day I have attempted to run WOT since the sea trial in March. I have also switched to e10 since getting anything else is not available on land around here. My fuel economy dropped about 5%, however it was 90 and humid today. Also with 100 gallons and 4 people on board, I could only hit 43 mph. Port engine was at 5500 rpm and starboard would hit 5600 max. I don't know if it is a fuel restriction, e10, the heat, humidity, or all of the above. Have you noticed any of these variables affecting your top end?