21' Paramount lower unit or no?

[ares650]

I currently have a 21 Paramount with a stock 225 Johnson on a 5 1/2" CMC jackplate I'm spinning 22 Raker @ 5800 rpm GPS 60.4 mph. Do you guys think a Bob's lower unit will help me? 4 cyl gearcase? I'm thinking about adding two more inches of setback aswell. What would be the best way to go at this point?

[BLACKPOWER]

Boat looks like this one.....
http://www.paramountpowerboats.com/images/Demo_21.JPG

[ares650]

yea.....

[VectorPat]

What year is your boat? I have a 92 that had a 200 merc on it and ran about 53mph at best. I now have a 250yamaha on it and runs 58mph. I have the same jack plate as you. I think propping is my biggest hold back. I dont think you would really gain that much with a bobs cone on it. I can jack mine up as high as the plate will go and not lose water pres. You might get alittle more speed with more set back but I think you may run into porpising problem at low speed. I could tell a big difference on mine going to this heavier motor. I do plan on trying a VMAX gearcase on mine just to see what it does. It has a lower water intake and pointed bullet on it. I'll let you know how it goes.

[ares650]

Thanks VectorPat
My boat is a 98...and I can also pull the engine all the way up with out any water persure loss, but when I do the boat pull to the right...bigtime. I also have a 21viper prop and with that the boat runs about 56mph @ 6000.
You think I sould play more with the prop and setback? I just thought about the bobs cone cause I remenber they had said something about mph gains on a test boat.

Thanks!

[SUPERBASH]

How HEAVY is this 21 ??? Speeds seem slooowww (even for a johnstone & a yammie :D )

ares650-Spinning a 22P @ 5800 your speed is maxxed out. Is it on the limiter ? Go up in pitch. Bobs lower isnt gonna do anything. More Setback isnt a miracle cure either.

VectorPat- What pitch you got on the 250 Yammie???


**For reference: My 21 Superboat Millenium (CenterConsole 1500lbs less motor) 250 MERC EFI (1:75's) would spin a 27P TrophyPlus @ 5700rpm 76-77mph gps (1 1/2" below the bottom.)
I'd throw a 22P on for skiing & BANG the limiter @ 62mph as well. http://i3.tinypic.com/11h6otk.gif
http://img226.imageshack.us/img226/1092/21ccsmall8eb.jpg (http://imageshack.us)

[ares650]

my rev-limiter is 6400rpm (that is what I recall) and I think she is about 1800lb or so, less motor.
Superbash...how much setback do you have?

[VectorPat]

I beleive mine is 1800# also, but not sure on older models. The 200 merc I had originally on it ran at best 53mph @ 5600rpm with a 21Laser. The 250Yamaha with the same prop runs 57-58mph at 5800rpm. The prop I know sucks for this boat as I can here it ventilating any time I accell from any speed. I am trying a 21 mirage this weekend and will see what happens. My rev limit is 6200 but these motors start running out of power before that. The boat does not like alot of trim it just starts to slip more at anything past halfway. It likes to run flat. I know it should capable of breaking 60 easily its just going to take some work.

[mad dan]

Most paramounts run to flat,a freind of mine has his counsel all the way to the back of the boat,with the gas tank back a little too.the boat runs about 70 with a 200 merc.the down side of this is the boats wortless for fishing.

[ares650]

That is what I felt, that the boat likes to run flat. That is why I thought about addeding more setback. I remenber that I gained about 3mph with a 5.5 jack-plate.

What else could help with lift?

[ares650]

hay superbash!!!!!!
How mush setback is on a 21 Superboat Millenium? Do you have any pics of the under side of your boat or a 21 Superboat Millenium?

[VectorPat]

You can get 2inch spacers to put in between the jackplate and motor. It might be worth a try and wont cost as much as a new jackplate.

[ares650]

Yea....I was thinking about doing that with the spacershttp://www.cook-mfg.com/spacer.jpg ......But it amazes me how two boat similar, could be so different in speed.

[VectorPat]

If you look at the pad on the Paramount, you can see where on the outside of the pad about 5ft from the transom it widens out. I will get some pics of mine when I get home. I think this area may act like a hook and be forcing the bow down and the transom up. I think if you can get the hull to lift past this area you may be able to gain more speed. Mad Dans buddy may have done this by moving all of the weight back.

[VectorPat]

Here is what I am talking about..

[Reaction19]

Paramounts Are All Sloe They Ride Nice In The Chop But Have No Mph I Dont Know Why. My Reaction19 With A 200 Carb Merc Will Run 73mph All Day Long With 52 Gallons Of Fuel And Two People In The Boat With A 25p Trophy. Prop Shaft On Mine Is 2 1/2 Below The Bottom With 12'' Of Setback.

[SUPERBASH]

A hook is a hook. You cant get around it with setback. Been there done that.http://i5.tinypic.com/13z3neo.gif

[AirRide]

a Paramount that does 60, then you have an unusually fast one. AirRide

[steelman123]

i've got a 2005 / 21 paramount w/225 optimax. my cav plate is about 1/2 inch above the pad running a merc 21p tempest prop and a hydra jackplate with about 5 inch set-back. boat easily runs 59.5 on gps at 5750 rpm and could still use more prop. this paramount dosent run flat as some others tend to say. actually when trimmed out i wish i had a seat instead of a leaning post because the haul is known to get a bit loose and dance around.

[ares650]

Paramounts Are All Sloe They Ride Nice In The Chop But Have No Mph I Dont Know Why. My Reaction19 With A 200 Carb Merc Will Run 73mph All Day Long With 52 Gallons Of Fuel And Two People In The Boat With A 25p Trophy. Prop Shaft On Mine Is 2 1/2 Below The Bottom With 12'' Of Setback.

You see....That's funny cause I have out ran a few Reaction, and then I have been riped a new by some 22-23 footers. What are you spinning your motoer too?

[VectorPat]

i've got a 2005 / 21 paramount w/225 optimax. my cav plate is about 1/2 inch above the pad running a merc 21p tempest prop and a hydra jackplate with about 5 inch set-back. boat easily runs 59.5 on gps at 5750 rpm and could still use more prop. this paramount dosent run flat as some others tend to say. actually when trimmed out i wish i had a seat instead of a leaning post because the haul is known to get a bit loose and dance around.


Mine doesnt have much bow lift and it gets loose over 55mph also. Just the nature of the beast.

[JBS]

I have run my 21 Paramount now for 10 seasons.It has a 20'' stainless marine bracket and a 6'' cmc hyd jack.Its powered with a merc 250. I run a 23 laser prop.It runs 66 [email protected] also run a high 5 for fishing offshore.I could probably stand alittle more wheel,but this is my fishn and all purpose boat.Its not a speed demon but does respectable for a center console heavy hull,1800lbs.I have some spare wheels for the big boat,24 raker that i want to try out.If,I see a difference,I'll post it.Thanks JBS