Are my speeds off???
 

im wondering whats up. with my boat, is it off?

my buddy has a 25 out law, stock 454 385 hp boat is said to be 4600 pounds.
i have 26 checkmate, 496 375 hp said to be 4200 pounds.
he runs in the mid 60's all day long. 64-66

other checkmates im seeing close to mine seem to be in the 65-68 range with 385 hp 454 and 375 hp the 425 hp are said to be 68+
is somthing up with my boat? im lucky to go 60. it has to be perfect for me to run 60 mph thats with low fuel and one person. however with 7 people full fuel and full coolers i was still able to see 58+
whats up?

4 blade prop, and yes i know how to drive, trim, and tab. we put my prop on my buddys boat he lost 2 mph on the nose with the 4 blade, that still onlu puts me to 61-62 mph.

i was ok with it till i see others with same boats claming mid-upper 60 on gps. one was over 70 gps.

whats up?

Whate is your drive ratio compared to the other boats? It could be the prop, it could be how smooth the hull is, it could be a difference in drive ratio. When you are only talking a couple miles per hour, it could be a minor difference.

same 1.5 ratio, we put my prop on his boat and he was still 2-3 mph faster.

noyzee, I've got a buddy with a 24 convincer sport, he's got the 454mag efi and Stainless Marine exhaust. He's a little lighter than you, I think about 3900 dry, 1.5 ratio bravo one spinning a 23p mirage plus. He see's 68 regularly and has touched 70 twice or so in perfect conitions. I have found that his boat is very sensitive to weight.
I know checkmates have alot of bowlift maybe try a fourblade cleaver style hydromotive for a little sternlift and get the boat out of the water. Seems like yous hould be in the 65-66 range one the go-fast.com speed calculator. What rpm's are you turning at WOT?

i have the 4 blade now, it doesnt seem like it has aallot of bow lift, it rides real level seems like it rides good to me.
heres a pic this is not 100% wot or trimmed up, but close.


http://img.photobucket.com/albums/v3...e/P6280390.jpg

IMG]http://img.photobucket.com/albums/v357/Noyzee/P6280393.jpg[/IMG]

sounds like you have a deep X dimension... the 4 blade may be holding you in the water.
Consider trying a Mirage plus, 1 size bigger than your current 4 blade. If the X is deep, the 3 blades are better.
Carder

i would try the three blade. most of the time a three blade is a little faster. need to know what rpms you are running.

try a 3 blade , if it gets on plane pretty easy with a mirage plus then your drive is deep, find a 23 pitch, maybe a 25.

i'll have to throw my buddies 3 blade on it, but we put my 4 blade on his boat and only lost 2 mph. im still 4 mph or more off?

I'd be checking the bottom of your boat. First is it suported correctly on the trailer or lift? look down the hull from the back and look for anything that is not straight.
Second, I know Checkmates are cored, but I'm not aware that they are vacuum bagged. Which would mean that delamination is very possible. To check for this, use the butt end of a screw driver and simply tap on the hull bottom listening for any sounds that are not a solid 'crack' noise. There could be hollow sounds and there could be dead 'mushy' sounds which would be bad and would suck away your speed.

BINGO!!

We had a 1997 24 convincer 385 h.p. 454 mag. The boat ran 69.5 gps with a 23 pitch mirage 3 blade. I had a 24 pitch 4 blade bravo one labbed and the boat still ran a solid 69 mph. Looking at the photo it appears that you need to get some more bow lift. These boats run fastrest with a lot of trim balanced on the pad. Hope this helps.

3 blades or hydros are no good on this hull, been down that road before. You need a labbed bravo with added cup. Looking at the pic of your boat running the hull is VERY wet!

yea, it seems like it runs to much in the water, like its dragging it down.
i trim it up untill she starts to over rev. it runs faster and faster as i trim, then bang, rev limiter. seems like i need to mess with the prop. would a lab fin from Merc work well?

Fromthe photo, it doesn't look as if the boat is even getting up on the pad. It would be worth calling BBlades and showing them this thread with the photo. Im sure it's something they can help with.



Darrell.

If you are bangging the limiter with that kind of ease you definately need a bigger prop. You also need to add cup to get more bow lift and get the boat back on the pad wear it needs to run. BBlades is your answer.

Do you have extra bs in the cabin? Keep in mind if you run with a extra 100-200 lbs in cabin boat will run wet. My buddy "old Navy" on here has a checkmate,it ALWAYS runs wet and heavy because his woman brings enough stuff for 2 weeks (suitcases,cans of baked beans,winter clothes,phone books for most mi area codes,arts and crafts,lawn furniture-YOU NAME IT:evilb:) in the cabin for a after noon ride,Smitty

here is a couple more.

as for stuff in the cabin, yes, sometimes there is a **** load, but in these pics, and on my top speed runs theres slim to none. besides the 15" sub woofer in the very bow, but the boat ran the same befor and after that.

http://img.photobucket.com/albums/v3...e/P6280390.jpg

http://img.photobucket.com/albums/v3...e/P6280399.jpg

http://img.photobucket.com/albums/v3...e/P6280393.jpg

http://img.photobucket.com/albums/v3...e/P7120484.jpg

http://img.photobucket.com/albums/v3...e/P7120483.jpg

http://img.photobucket.com/albums/v3...e/P7120488.jpg

http://img.photobucket.com/albums/v3...e/P6280396.jpg

http://img.photobucket.com/albums/v3...e/P6280397.jpg






also, i dont know if these photos are all out, it might not be trimmed up 100% im sure she isnt exactly where she rides, but its pretty close

You're running way too wet. At WOT and trimmed up, you should be running with only the last 5 feet of boat touching the water.

Check for some hook in the last 3 feet of the hull.
Do you have tabs????? How are they in relation to hull when all the way up????

the hull looks ok i took a straight edge about 2 feet long and ran it down a few spots and it looked good. the boat has no stress cracks or anything to show its out of wack.
i have to admit its original plugs and wires 230 hrs old

as for tabs, they are 12" long, they sit about 1" from the very bottom and sit out just a tad in the upward possition. the boat however always twists towards the left i alway half to trim the starb side down or port side up when cruzing. when im WOT its fine. it does this with just me in the boat, no one on the other side, and any weight i have in the boat is all right in the middle or close.

it seems like prop is the issue imo from what you guys are telling me. i hit the limmiter very easy and thats when she falls off.

im a little iffy on a prop however, id like to do a merc prop, my friend got a bblades and had a few issues with it and im not sure i want to spend 1,000 bucks and take any chance

You can get loaner props from BBlades, nothing lost but $25.00, and valuable information gained.
Carder

they do loaner props? if thats the case im going to contact them right befor spring to get on the list (the boat goes into winter storage this weekend:()

but i will give that a shot in the spring. if the prop works well can you just keep it and pay with a card or what ever?

Might want to change your plugs and wires before next season as well. A good tune up will make a world of difference.

thats the plan, i already have the stuff to do it. i will do it in the spring as the boat gets put away this weekend in the indoor racks for the winter sad to end the season, but its sled and race time now.

Bretts custom labbed props aren't a grand and there cheap than merc racing. Even better yet he used to work at merc racing:cool:

do you have contact info?

He is an OSO advertiser. What prop are you running now, what rpm are you turning it?

920-295-4435 ask for Brett.

right now its the stock 4 blade. i think its 15 3/4 23 or 22 pitch i get the 3 and 4 blade mixed up. im new at this prop thing. lol

Probably a 22 bravo one if its a 4 blade

It's a good looking boat, but...
 

judging from your photos, you're getting too much stern lift and dumping-in the bow.
Griff is right...you're running too wet. Too big a footprint, too much resistance to forward travel. Your boat looks like you're running with the drive fully down. Next time your boat is in a travel-lift, check the weight.

First thing you need to do is get a prop that isn't banging the limiter. You say you easily hit the limiter. You shouldn't hit it at all. If you're hitting the limiter that easily, you're not able to let the boat free up from the water or trim it up fully.

A 22" Bravo 1 prop is a 60mph prop at best with a 1.5 geared drive and stock power. Try a stock 24 Bravo 1 prop and go from there.

This is about the attitude you want to be running at WOT.

great info guys. im going to check what the prop is, i was going back and forth when i broke my old prop and i just went with a stock one, now i forget if it was 22 or 24, i like the 4 blade allot tho so im ok with loosing the 2mph, but i think im off more like 5-6 so im ok with the 4 blade and picking up 3-4.
the boat is 2 hours away now, so im not sure when i can check, but i guess i will have to go from there.