• Welcome to the Checkmate Community Forums forums.

    You are currently viewing our boards as a guest which gives you limited access to view most discussions, articles and access to our other FREE features.
    By joining our free community you will be able to:

    » Interact with over 10,000 Checkmate Fanatics from around the world!
    » Post topics and messages
    » Post and view photos
    » Communicate privately with other members
    » Access our extensive gallery of old Checkmate brochures located in our Media Gallery
    » Browse the various pictures in our Checkmate photo gallery

    Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact support by clicking here or by using the"contact us" link at the bottom of the page.

Have a question?

175checkmate

175checkmate

Moderator
Staff member
Jackplates, props, engine, steering, help with something. Woundering about this, that, and another.
Ask away. Together we may be able to help.

2982rooster_3.jpg


1975 Checkmate Tri-mate 2, 2.4 200+
 
I have a 15' V-Mate (600 Lbs.) with a 100 HP Johnson. The motor is currently on the transon, as high as possible, shaft 5" below the boat. The prop is an old 12 3/4 x 21 SS OMC. It runs about 50 MPH currently.

You mentioned adding a pad in another string. What improvement could I expect from that mod on my boat? How would I do it? Dimensions?

Also what setup works well on this model? Should I add a jackplate? Setback?
 
First Welome.
since all boats are diffenent I can tell you what I did and what improvements I have seen.
1. Before you go through the pain of adding a pad. We need to get your boat set up.
On my c'mate ( 16.5' and 850lb 200hp. 25P ss laser 2 prop ) I have a hyd jackplate, no cone or low water pick-up, and no set back.
If I put my plate all the way down, ( this would be very simular to what you have) the prop shaft is about 6" below the pad. My top speed is about 55, and the boat has a hard time brearking free of the water. Now with the plate all the way up, about 2" below the bottom, I still have good water Psi and the boat will now run 66-68 depending on conditions.
With the motor up, there is alot less drag in the water.
I am adding a 5" setback jackplate for the following reasons.
1, The set back will change the pivot point of the motor, giving more leverage, better to pick the bow up. (C'mate's are bow heavy)
2, It will alow me to lift the motor even higher when used in conjuntion with my hyd plate.

Adding a pad is not exact. The new C'mates use a 4" pad, hydrostream vector 8" Vking 10". Each boat is different. Rule of thumb. the bigger the pad, the more drag, easer to drive, smaller pad, less drag, more dependent on set up and driver.
I am installing a 9" pad on mine and running about 6' towards the bow. This is just a best guess. I'll let you know how it works when its done.

I would start by adding a jackplate, there are 3 types, manual,(need a engine lift to raise motor)
Manual adj. ( these have adjment bolts on eather the sides or in the center, can raise and lower witha set of wrenches)
And Hyd. these are nice if you want to more than just go fast. Up for fast, down for sking. Most manual plates are between $110-150. Adj, plates $150-300. And Hyd used start at around $400.

What OMC prop are you currently running? How many RPM are you turning.

I hope this helps

2982rooster_3.jpg


1975 Checkmate Tri-mate 2, 2.4 200+
 
The prop is a standard thru-hub 12 3/4 x 21 with a cup. It has a cleaverish shape. It runs @ 5100 rpm. The hole shot is good but a little ventilation would help - only revs to 2700 then accelerates smoothly. Raising the motor should help that. Prop slip is currently very low - ~5%.

I don't have power trim. The bow seems light enough with a light load. I normally run @ 1 deg positive trim. The next step is ~5 deg. That produces ~1 mph faster down wind but is dangerous up wind without a heavy passenger.

I have Ride-Guide single cable steering and stock mounts. Chining has occurred. Hopefully raising the motor would reduce that. A pad might also - right?
 
Raising the motor should help. I get not so much a chine with the motor all the way down, but more like a wiggle. I have solid mounts on the top. Single cable steering for now. Thats going to be changed in the spring to a duel cable.
Do you have a water psi gauge installed. Good insurance when rasing the motor.

2982rooster_3.jpg


1975 Checkmate Tri-mate 2, 2.4 200+

[This message was edited by 175checkmate on December 05, 2002 at 01:35 PM.]
 
Just sent you some pictures VIA e-mail. This was a pad install on a baja.

2982rooster_3.jpg


1975 Checkmate Tri-mate 2, 2.4 200+
 
hey fellow boaters ,i need some help.I cant get my 242 to go anyfaster.i have a 454 mag with bravo 1 outdrive.Iv'e heard that even if i were to put a 500 efi in it with a bravo xr i wouldn't push it any faster.i'm in the low 70's now.but i have a need for speed disease.please help.
disturbed
 
Sounds like you are doing great with low '70's and a 454 in that size boat. I'm assuming that's GPS speeds, verified over several runs (I've seen inaccurate GPS readings) and you have already optimized your setup with a sweet prop. To go faster, you'll have to spend LOTS O DOUGH. The 'Mag' version of the 454 means it can handle a low pressure supercharger without internal mods PROVIDED you have the engine dynoed and dialed in properly. The fuel curve must be properly calibrated throughout the RPM range, otherwise you'll explode it. A properly installed/tuned supercharger is the least expensive and most reliable way to gain speed. Go into the motor with better parts (valve springs/head gaskets/etc..) and you can turn up the boost and go even faster. Personally, I don't like modified engines. When I need to go faster, I buy a faster 'stock' boat :-) Good luck!

1995 2100BR/1995 225 Promax/23" Tempest
 
Disturbed,
What kind of rpm's are you turning at wot? The first way to pick up 2mph is to dump the 4blade prop and goto a 3 blade, probably a 24p. Do not call Kip at Checkmate, call Mike Combs, he is the performance guru down there. Your 4 blade is good for hole shot and mid range accelleration, but because you have more drag, it slows you down. I am going to be carrying both a 4 blade and 3 blade in my 240. Just to give you an idea what horse power you will need, in the mid 1990's I swaped a 502 mag for a HP500 in a 253 Convincer and it would do about 78 on speedo, so roughly a true 73-74. You will need MORE than just a blower.
 
Rigmaster

1986 Checkmate Exiter/
175 merc black max
21p s/s not very aggressive.

I am in the parts business for a 4 store marina here in MI.

1. Without a jackplate, how high can I go from the centerline of the prop shaft to th bottom of my pad?

2. To defray costs, is it possible to put a 90 deg fitting on the bottom of the boat to use as a "low water pickup? Monitored by a gauge?

3. Should I use a setback-fixed plate?

OR...
What is the way to go?


Help-

Thanks for your time...


Jack Frost
Union Lake, MI
packetshifter@yahoo.com
51 Yr Old Ex-Motorcycle Racer,
wife said I was going to die...
Well I do know-that just by changing the jets and a little tuning/ walla 200hp.
 
Wow, you've pulled up a 5 year old thread.
There's not too much you can do till you get a JP. If you start raising your motor the prop is probably going to start slipping. Mates have a transom 2" higher than most boats to begin with.
First thing you want to do is get a 8" manual adjustable JP on that thing. Then you can do some baseline RPM work and figure out what prop you should try. I would think you should be able to turn a 24-25" SS prop.
Maybe someone with your exact hull will know for sure.
 
175 Checkmate....your post on Jackplates and Pads should be framed and titled " Set-Up 101" . One of the best and most straight-forward-no-frills on the subject that I've read in many years. A suberb job!

Just had to say it....
 
You must log in or register to reply here.
Back
Top