Engine hp and Maximum mph at maximum throttle (WOT)

[flagold]

Engine: 90 Mercury (you knew that already . . .)
RPM: 5400
Speed: 33 mph (full water full fuel +12 gals full dive gear + hookah rig)

[DodgeRam]

Now that you have the attention of a few see brats , it might really be helpful for some of the C Brats that are still looking to match their prop (s) , to know all of that, plus type of engines, HP , max rpm, top speed. So if we had problems matching prop(s) to our C-Dory it might be easier than have to run back & forth to your suppliers. On my sea trials with different sizes I had the right prop at one time but but kept on trying other sizes. If I would had known what I learned those past few days through this forum it would had been lot simpler and probably would have not dinged a prop that I did not need. Gary

[flagold]

Stock Merc 17P in my case. I agree with Red Fox on using the stock props, they generally cover all applications an are relatively cheap to have spares aboard.

[Notayot]

Honda 90 (34 hours on engine) about 5700 rpm and 31 mph by GPS with two on board and 25 gallons of fuel plus all the usual safety stuff. Mileage is running about 3.4 mpg.

[C-WEED]

80 H.P. Yamaha
well worn stock 3 blade 13.75 x 15 prop
rough bottom paint
5600 RPM
30.0 MPH

[Redƒox]

One trip: super-duper-heavy with 5-people-

115 (Yami Fourstroke) 5700 rpm@28 mph.
rough bottom paint here to! that makes a dif' used to be faster!

The last trip: (and I always "see-what-she-will-do) Jus Pirate Deb and I (moderate-load) -

6000 rpm @ 34.3 mph

Everything varies from trip-to-trip: tides, wind, current, air-density .... etc...)

If your not able to pull your max-rpm, ya really ottah prop-er-down, at least for the engine sake of not lugging it
and better milage

uh oh... there I go again soundin all "know-it-all" forgive me ...

[therevdr]

I just discovered this topic....it seemed interesting enough to keep it going!
22' CRUISER....TWIN 40 HP HONDAS.....(at optimum conditions - no waves or wake) 31.4 MPH at about 5100 RPM and engines trimmed up!!
The go-fast boats on Lake St. Clair (Michigan) fly by, but I won't want to go any faster (and I don't want to pay the "go-fast" fuel bills!!)
therevdr

[jennykatz]

with 90hp suzuki with 5hours still not broken in yet on 22 cruiser full gas and h20 plus some tools chairs etc. painted bottom used gps for speed
4000 rpm 18mph

4500rpm 22mph

5000rpm 27mph

6000rpm wot for 1min 34.4 mph

this is with stock 14in by 18in pitch s/s

[Sneaks]

C-22 tall top cruiser, full tanks, misc "stuff", heavy helmsman, F75 Yamaha EFI, trim tabs

29.7 mph, 5500 rpm, San Diego bay.

Might have made 30 mph, but I was dragging my fenders as well.

[joeC]

C-Dory 25.5 Tomcat twin 140 Suzukis 20 pitch props about 50 gals fuel 2
people best GPS 44.2 mph also at 4000 rpm cruise about 27 mph roughly
2.2 mpg
Joe

[Bob Cat]

Hey, Joe

This is the first data I've seen on fuel consumption for the TC255. Not too bad. I'd imagine about 2.0 with full fuel, load, etc. If you've got the time, perhaps you could post your impressions and experiences with your Tom Cat in a new subject or under the New Tomcat 255 subject that already exists. Mine is at the SBS, then back for final rigging and pickup around mid Feb.

Thanks for the important info!

Bob Cat

[DodgeRam]

WOW, Joe when you say roughly , means you don't have a fuel management gauge right? SEARAM

[joeC]

Guys
My last post I said roughly 2.2mpg the way I figured this is by the amount of fuel I put in the boat each trip wich is 15 gals. per side. The first fill I used 5 gal cans to get an idea what the gauges were really telling me. I boat on Galveston bay and the rivers and always reset the Gps odometer
to zero before the run. Flow Scan equipment will be on the boat before long but my wallet is not always thick enough for toys. I have been experimenting with motor heights and at this point think they are still low.
Now they are 1 hole up from all the way down which is .750 inch up. the boat on a speed run really likes a lot of up trim which leads me to believe
that the motors are low. The reason I am doing this is a boat that is set up right has a lower fuel burn and normally just performs better. Since I bought the boat I have had a lot of little issues but the punch list is about over now Ie it all works. Funny thing I pulled the Suzuki's off of my other cat which weighs 2500 lbs less then the Tomcat but the Tomcat outperforms the old boat at every Rpm. For those who are wondering the other boat is was I need to sell it a 22.7 Seachaser cat . Next on my list is gen and ac it is very hot in Texas then chart,sonar, radar.
Joe

[Luna C]

90 hp Suzi
5800 rpm
29.8kts