just joined need advice

[bert]

although boating for years have only just bought phantom 21 and given it a full refit but i am unsure on performance side
i have a 2.5 200 carb slightly raised but standard running standard merc 23" prop giving me a top speed of 68mph according to my speedo, would like to get into basic racing is this about right and what could i do to get more out of it rpm 5700

[Captain Chaos]

who thinks "Bert" might become my new best friend?

[bert]

what do you reckon then

[Jon Fuller]

Spoke with Steve Baker this morning about 21 performance, the original test boat ran 68mph with a 200 (timed)

[bert]

so how can i make it a bit quicker without spending thousands

[Jon Fuller]

bigger engine.

stand off boxes, and jack plates etc will improve top end, but a fixed stand off box will also have detremental effects, and hydraulic jack plates are quite expensive, plus it's something else to wrong.

More HP is the logical way to faster, everything else will be a compromise in other areas, basicaly, everything is a trade off,except more power, and you can't have too much of that.

[bert]

is there things you can do to increase hp of this engine or will changing the prop do anything

[Jon Fuller]

To be honest, if Steve Baker got it to do 68 as a stock set up with 200, you're unlikely to go much, if at all quicker, he is no fool.

You might get a smidge more out of it with a diferent prop/more rpm, but I think 6000 is about top for that motor anyways.

what prop is it? (as in model)

[Jon Fuller]

Originally posted by Matt
Am I right thinking that a stock 200 has 1.87:1 gears?

Yeah.....that says 59.7mph!!!???(10% slip)

[Jon Fuller]

summat aint right

[Jon Fuller]

You didn't let JW build you a cabin did you?

[bert]

not sure have to get back to you on that its just often see same sort of rigs advertised at 70mph plus as for basic racing what sort of speeds are the same boat with xr2 reaching and would i still be able to go in that class even though it is a 2.5 what i would realy like is a promax 300 but what class would it go in and would i stand any type of chance or am i just wasting my time

[Jon Fuller]

Sadly, many people in powerboating get a little overexcited and confused with their top speed claims. However, it should be perfectly possible to achieve upper 60's with your boat, assuming it's mechanically good, and the boat isn't full of water (in places you can't see), weight is your biggest enemy as far as speed is concerened, especially if it's up front.

the 300 promax comes in two types, one at about 275hp, and one at about 320hp (the 300x), with a 300x you'd be well into the 80's I would think.

Incidentally, do you know what year/model your P21 is? as there has been about 3 variations on that hull since the 70's

if your not sure, get the Hull number off the st/bd transom and refer to This thread

[Captain Chaos]

Information overload!

All i need to know is how Berts got his set-up?

that way i know i'll do 60....and then my pants will be safe!!

post some pics and then measure where it is on your transom.....i'll be a happy bunny!

what prop?

get a new HO evinrude............it'll go like F*ck! Oh actually so will will any promax, or even better (weight wise probably) a 2.5 EFI 280.......job done

[bert]

right i`ve been ripped off with the boat 811015 which makes it 1981 bloke told me it was early 90`s engine is merc 1996 though prop is a quicksilver 48 A40 23"p the engine is raised 4" meaning the plate above the prop is 4" from the bottom although it is this old the hull seems in good condition got some photo just dont no how to put them on here just tried took up whole screen

[bert]

are any of you going to littlehampton or the poker run in southampton i am hopeing to be at both

[Jon Fuller]

Originally posted by bert
right i`ve been ripped off with the boat 811015 which makes it 1981 bloke told me it was early 90`s engine is merc 1996 though prop is a quicksilver 48 A40 23"p the engine is raised 4" meaning the plate above the prop is 4" from the bottom although it is this old the hull seems in good condition got some photo just dont no how to put them on here just tried took up whole screen

You need to resize the pics to 640 pixels wide, if you don't have the software to do this, email the pics to me at ************** and I'll do it for you.

JF

Ok, done that look Here to see the pics

[Hydrostream]

I really wouldn't care how old it is, as long as it's sound and you like it it might as well be a 2004.

You say it's a 2.5 carb, but on the cowl it says XR2, Xr2's are 2L engines. I think you could go a lot faster with a 2.5 with some set-up!
Also if it's a 2.5, I don't think you can race in class 3 'C', guy's here will know better.

Alan

[bert]

when i went to buy it thought it was a xr2 but turned out to be 2.5 200 with xr2 cowling i bought it because bloke took my old boat in part x which was pretty nakerd i am pleased with it cause done alot of work so is all now up together but would now like to get in to racing but fear because its 2.5 its to big but still only 200hp but wondering if anyone would care in basic racing as it has no points and same hp as xr2 and would anyone realy notice or care

[jackeen's Missus]

Originally posted by bert
are any of you going to littlehampton or the poker run in southampton i am hopeing to be at both

A few peeps from the Forum will be at Littlehampton Bert.

Missus