228 performance

[fathergoose]

I just purchased a 2009 seafarer 228 with a 2009 250hp Yamaha. I'm a little disappointed with the performance and think that I might need to change the prop. It has a 15 1/2 x 17 which is the recommended prop. The boat will wind up to 6100 rpm with no problem but the speed at WOT is only 39 mph. At 4500 rpm I am only getting 25 to26 mph. The speeds are from the GPS not the gauges. The bottom is painted and appears to be fairly smooth, it has a hardtop with side curtains, the front and rear curtains are rolled up.. The fuel tank is a little over 3/4 full. I was expecting the top end to be in the low 40's and cruise speed at 4500 to be around 30. Are my expectations off base? How does this compare to other 228 owners performance?

Thanks

 

[DennisG01]

What's your max RPM spec for the engine? 6,000? If so, you certainly have room to jump up to a 19" and see what happens. I have a 17" on my boat and I can touch 40mph in the right conditions and that's right up there near the top range of my RPM spec. Where are you using the boat - that can make a difference.

FYI... what type of motor is it? It would be good to clarify that and include it in your signature.

 

[fathergoose]

The motor is a 250 four stroke. I'm using the boat in the Chesapeake and Delaware Bays.

 

[Doc Stressor]

For whatever reason, you're getting a lot of prop slip. I calculate anywhere from 21-28%. So either your engine is mounted too high or there is something wrong with your propeller.

I've seen people mount engines too high on bracketed boats in order to try to improve fuel economy. This can be overdone. Does you prop blow out in turns? It should never blow out. If it does, the engine is mounted too high.

17" should be about right for that setup. Have a prop shop check out your current propeller and/or try a different one.

 

[Ky Grady]

I'm running a 4 blade prop on my 228 with F225, I can run 40-41 mph/GPS @ 6100rpm. 2 people, 56 gal. of fuel, no curtains, no bottom paint, motor mounted in the 3rd hole down from top.

 

[DennisG01]

Is 6K the top end?

Altitude not an issue.

When you checked your speed runs... did you happen to do the same thing going the opposite way? Wind/tide/current can certainly account for a few MPH. Is the WHOLE bottom smooth, or just the sides? Prop in excellent condition? Just want to try and get rid of variables here.

 

[UCPA111]

1984 With 2018 Verado 300 (I6 Model). I am at 48 mph with a little over half fuel, hard top, curtains up, 3 people and full gear. I am running a 4 blade, 17P Rev 4 prop. I backed down from a 19P 3 blade to get the RPM in the sweet spot.

My cruise is 2.7 mpg at 28-31 mph....

 

[fathergoose]

Is 6K the top end?

Altitude not an issue.

When you checked your speed runs... did you happen to do the same thing going the opposite way? Wind/tide/current can certainly account for a few MPH. Is the WHOLE bottom smooth, or just the sides? Prop in excellent condition? Just want to try and get rid of variables here.

Top end is 6100. The whole bottom looks pretty good. I have run in both directions and at various locations

 

[DennisG01]

Top end is 6100. The whole bottom looks pretty good. I have run in both directions and at various locations

No, I mean what is the spec for the engine? 6K is the upper limit?

 

[fathergoose]

I believe the spec is 5900 to 6100

 

[fathergoose]

For whatever reason, you're getting a lot of prop slip. I calculate anywhere from 21-28%. So either your engine is mounted too high or there is something wrong with your propeller.

I've seen people mount engines too high on bracketed boats in order to try to improve fuel economy. This can be overdone. Does you prop blow out in turns? It should never blow out. If it does, the engine is mounted too high.

17" should be about right for that setup. Have a prop shop check out your current propeller and/or try a different one.

I’m not experiencing any blowouts when turning at speed. The motor winds up to 6100 very easy so I’m thinking that it’s a prop issue. The only other thing that I can think of is an issue with the tach causing it to read higher than actual rpm and the rev limiter stoping it at 6100.

 

[DennisG01]

Is your rev limiter actually kicking in?

There is a small chance that your prop's blades have flattened out a bit... in essence, lising a bit of pitch. A prop shop can check it.

I still think it's worthwhile to test out a 19".