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Old 01-28-2015, 05:02 PM   #11
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Hi Shrew,

As mentioned in my previous post it is around 4600 to 4700 RPM @ WOT trimmed out with no tab @ approx 38 mph as previously mentioned I have not taken the boat out for some months now hence the approx !, pretty sure it is right though and the speed at 3700 - 4000 RPM is approx 25 - 30 mph vs approx 10 mph @ 3000 RPM.

Thanks

Jamie
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Old 01-29-2015, 02:40 PM   #12
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Hi Shrew,

As mentioned in my previous post it is around 4600 to 4700 RPM @ WOT trimmed out with no tab @ approx 38 mph as previously mentioned I have not taken the boat out for some months now hence the approx !, pretty sure it is right though and the speed at 3700 - 4000 RPM is approx 25 - 30 mph vs approx 10 mph @ 3000 RPM.

Thanks

Jamie
Apologies, I had gone back to the first post and overlooked the second. I would not increase pitch based on these numbers. Your numbers would indicate you are propped perfectly for that engine and boat setup. If you increased pitch in order to achieve your target numbers it's going to be a pig climbing out of the hole and put tremendous load on the entire system unnecessarily.
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Old 01-29-2015, 04:45 PM   #13
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Apologies, I had gone back to the first post and overlooked the second. I would not increase pitch based on these numbers. Your numbers would indicate you are propped perfectly for that engine and boat setup. If you increased pitch in order to achieve your target numbers it's going to be a pig climbing out of the hole and put tremendous load on the entire system unnecessarily.
Already a bit of a pig for hole shot, I also feel the WOT reves are good and I am quite happy with the top end speed, I just want to get out of the hole a bit better any idea's ??
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Old 01-29-2015, 04:58 PM   #14
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In post #5 you said you don't really use the trim tabs, these greatly help get the bow down and the boat on plane. Also try shifting some weight forward, coolers into the cabin, ...
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Old 01-30-2015, 02:24 AM   #15
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Exactly what Mike said. Usually when I'm getting on plane with my 2500 scr I'll keep the outdrive all the way down and will drop the trim tabs about 70% down. As soon as it will get on plane I'll trim up the outdrive just a bit and bring the trim tabs up to about 20%. I drove few bigger boats and played with the trim tabs on them. My impression was that the bigger boats weren't that sensitive as far of trim tabs position. In my case trim tab set up got huge impact on getting on plane and also cruising. Weight distribution also plays a big role on boats our size.
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Old 01-30-2015, 05:15 PM   #16
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In post #5 you said you don't really use the trim tabs, these greatly help get the bow down and the boat on plane. Also try shifting some weight forward, coolers into the cabin, ...
Hi Mike

I have tried people in the front of the boat and all the gear and yes it does make a difference, although I am taking the boat for a service soon and a fresh coat of antifoul. I think I will get them to check over the trim tabs as well, I am sure one is a bit sticky, maybe this is why I did'nt use them that much last season.

I have also been speaking to a freind of mine, who is telling me that maybe this is down to the propeller being for a sport boat and not really designed for a good hole shot but actually top end speed ?, he thinks the weight of my boat might be causing a issue with this type of propeller.
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Old 01-30-2015, 05:23 PM   #17
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Exactly what Mike said. Usually when I'm getting on plane with my 2500 scr I'll keep the outdrive all the way down and will drop the trim tabs about 70% down. As soon as it will get on plane I'll trim up the outdrive just a bit and bring the trim tabs up to about 20%. I drove few bigger boats and played with the trim tabs on them. My impression was that the bigger boats weren't that sensitive as far of trim tabs position. In my case trim tab set up got huge impact on getting on plane and also cruising. Weight distribution also plays a big role on boats our size.
Hi Forbes,

Thanks for your input I like the 2500 SCR nice boat not too big to take out with just a couple of us, maybe I will trade up one day. I have replied to Mike and think I will try your set up when I take it out after i have had it serviced. Just out of curiousity what size motor or motors are you running and how does it go.
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Old 01-30-2015, 08:56 PM   #18
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The prop size you have sounds tight for at boat, if the tabs do not help enough you could drop one pitch this will increase WOT by about 200 rpm
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Old 01-31-2015, 12:18 AM   #19
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Hi Forbes,

Thanks for your input I like the 2500 SCR nice boat not too big to take out with just a couple of us, maybe I will trade up one day. I have replied to Mike and think I will try your set up when I take it out after i have had it serviced. Just out of curiousity what size motor or motors are you running and how does it go.
Its a single mercruiser 5.7 250 hp with bravo 3 drive. In my opinion this engine works really well with this boat. Its my first boat so I don't have a lot of experience with other but it feels like theres always more power then you need. Using trim tabs I can get on plane in no time and without gear and extra weight I was able to hit 40 mph. In my opinion 2500 scr offers a lot in this size/price range. Also its very descent on gas since cruising around 25 mph I'm burning not more then 10 gal per h. I bough it 2 years ago and today I can't imagine my life without it I think I'm addicted
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Old 02-01-2015, 06:20 PM   #20
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The prop size you have sounds tight for at boat, if the tabs do not help enough you could drop one pitch this will increase WOT by about 200 rpm
Hi Mike

I have been looking for answers on the net aswell and it seems that a 4 bladed prop should give me what I am after, this also recommends that I drop 1 pitch size, this sound promising. I can't wait to get back out on the water I've got alot of things to try this season. The weather has taken a bit of a turn for the worst at the moment it's a bit stormy with cold temps and some snow. I wont be trying it very soon.

Jamie
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