Seebold Ski Eagle / 2002 Merc 200XS / lots of slip

[DangerNewb]

Had a chance to run my new to me hull and engine. The hull has a good size bracket then a jack plate for maybe 12 inches of set back. I've got a ET cut Chopper 28 pitch 3 blade exactly 14 inch diameter. Tried jackplate from 1 inch above to 1 inch below pad. Saw 7000 rpm but only 75mph for best speed. According to a calculator that's almost 20% slip.

Gathering opinions before I buy another prop. Maybe I need more diameter with the fat shaft Sportmaster gear case. Interested in overall performance, good acceleration and decent top end. I'm hoping for 85mph out of it which seems reasonable if my motor will spin a 28 pitch to 6500 or so rpm with decent slip.

Also wondering since my engine is dumping all the exhaust down by the prop (I think) if I need something like a Merc Promax or Mazco HP4 to keep some of the exhaust inside the hub. Maybe I'm getting too much slip due to all the exhaust venting over the blades? I have a stock midsection. From what I've read, those props have hubs that are smaller than full size to sort of split the exhaust going over and through the hub.

The previous owner said the boat was weighed at the Jasper drag races at about 1550 lbs with little fuel and no driver and promax engine. So my XS weighs a bit more so let's says 1600 lbs. I was running it with a buddy which will be my normal set up. I can say the boat handles waves way better than my old Valero so happy with that but it doesn't accelerate like it did. Makes sense with the extra weight.

Anyhow, I'm not satisfied with my current set up so looking for advice. Thanks for any input.

I'll be going down for the Suwannee River run next week if anybody has a prop they'd like to sell that may fit my needs.

[David]

The over hub design will slip more getting on a plane but should work fine at speed.

how much trim are you using and how high is your rooster tail?

Try your buddy in the back seat. That might change everything. Even if you don't want to run with your friend in the back it's a good test

[JPEROG]

I have never run anything less than a 14 1/2 dia. Go a little bigger on dia. and raise the motor up until pressure becomes a concern. You aren't dealing with a lot of hp for that weight so you are going to have to minimize the drag.

Joe

[DangerNewb]

Thanks for the advice. I have a couple guys willing to let me try a couple of props next week. See how that goes. I tried the jackplate from probably 2 inches above pad to an inch below. Higher I went the looser the rear felt and more slip. What's the theory behind putting more weight in the back? This thing already sits with rub rail under water in back corners with nobody back there. Re: trim, the boat didn't respond to trim much beyond a little over neutral. It would just throw a bigger rooster tail but not really change the attitude of the boat. I've been told my ET cut chopper will struggle carrying the weight of the hull. Plan to try a couple Promax props next week so see how that goes.

[JPEROG]

You need to have enough dia. that there is still blade surface "tips" able to propel the boat while getting the motor high enough to not drag the case. A pro Et might be something to try. You need blade surface to carry the weight.

Joe

[DangerNewb]

The props I plan to try are Promax. I understand they are similar blades to pro ET but larger hub. The former owner was running Promax's on the hull with good results. He is one of the guys letting me try one out. Looking forward to sunny Fla next week

[David]

If moving your passenger back changes things a lot you need a bunch more lift from your prop, more setback, or both. Plan B would be to accept less performance with a friend

when I had a 150 on my Ss2000 moving a passenger rear was probably 8 mph. Now I have a 225 PM and weight is less critical.

[DangerNewb]

Had a chance to run it again. Had my son with me. When I dropped him off to get the truck I took a quick run. Totally different boat. It ran right up to 80 and would cruise at 70 with 3/4 throttle. So I'm thinking my prop isn't lifting the boat enough and I'm getting way to much hull drag. Looking forward to trying a different prop this coming weekend.

[DangerNewb]

Tried a 28 Promax at the Suwannee Run. Thanks to Mark. 80 with 2 people. Didn't really get to run it alone. Mid range was way better. With my ET cut chopper, 5k rpm was under 45 mph. Tons of slip. With the Promax prop, 5k rpm was upper 50mph. Carried the bow way better and overall responded to trim better. Plan to try a Ron Hill Eagle 4 blade 28 for one more comparison then decide to keep that or get a Promax prop. My ET chopper doesn't seem to have enough cup to carry the weight. Runs great on a lighter boat but not so great on the Seebold.

[91eagle]

Keep the info coming ill setting mine up very soon ....Thanks

[DangerNewb]

I bought a Ron Hill Eagle 4 blade. It works well. Still 80 top end but the mid range was very good. 60mph around 5200-5300 rpm. Lifted and carried the bow way better than my 3 blade. Overall I'm happy with it. I'd say the Hill prop ran as good as or better than the promax I tried in Fla.

I was able to get it to run 80 at about 6200-6300. Raised the jack plate and got up to 6800 rev limiter but didn't gain any speed. Guess it just slipped more. I was hoping to see 85 out of it, but maybe that's not in the cards without more HP.

[KIRCHNER]

JUST my 2 cents but never tried a std. big ear chopper/? lots of blade area & BOW lift best of all there cheap!

[KIRCHNER]

I have never run anything less than a 14 1/2 dia. Go a little bigger on dia. and raise the motor up until pressure becomes a concern. You aren't dealing with a lot of hp for that weight so you are going to have to minimize the drag.

Joe

IM RUNNING a scorpion 15. 25 dia x 26 diameter is more important than realized all kinds of lift very little torque huge rake and cup.i dont see why there not more popular love mine! a merc trophy looks tiny in comparsion

[drag120]

My warrior is 1 1/4 above the bottom and no setback. The farther back the higher you need to go. I was told not to run a setback but your hull is different than the warrior.

[DangerNewb]

I haven't tried a big ear chopper or a scorpion. Maybe if I get a chance soon I will. Pretty happy with the hill eagle 4 for the time being. Thanks for the feedback.