-
Welcome to the Checkmate Community Forums forums.
» Interact with over 10,000 Checkmate Fanatics from around the world!
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:
» 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.
80.3 in the Pulsare
- Thread starter kushog
- Start date
Okay just want to make sure I got this straight. You were running a Yamaha 250 Vmax with a 30" Mercury Pro-Max prop to a best of 85.8 mph, than you switched to a Yamaha SHO fourstroke and run a Hydromotive Quad4 15.5" diameter prop to a best of 92.8. And they both run best at 70 degrees or more outside temp. Am I on track here?
Okay just want to make sure I got this straight. You were running a Yamaha 250 Vmax with a 30" Mercury Pro-Max prop to a best of 85.8 mph, than you switched to a Yamaha SHO fourstroke and run a Hydromotive Quad4 15.5" diameter prop to a best of 92.8. And they both run best at 70 degrees or more outside temp. Am I on track here?
On track just saying not at 45 degrees and at 820 feet elevaton not sea level BB blades 30 was fast on vmax i see you have one but they are frgile 29 t1 fast to hard to drive in typical not so perfect water I dident try Hydrromotive on 2 stroke Checkmates seem to like stern lift
DO you have solid moter mounts. its hard to to drive with stock ones and good time to instal tunner
No, stock mounts but I'm not really having any "driving" issues myself.
I think I know what you mean kushog, and I may be totally wrong on this, but I wonder if it has to do with the motor height you're running at. What I noticed with mine is that I don't seem to have any chine walk with the motor jacked up high enough. First run after I went to 16" setback and mounted the motor so it could go 1" above pad, I took it over 70 MPH and for a moment I thought I wasn't even on pad (with just me in the boat and 1/2 tank gas). It was like I could have totally let go of the steering wheel. Then I lowered my hyd jack plate a bit and it started to chine walk. If yours behaves the same then solid mounts wouldn't be all that necessary if you're not getting chine walk to begin with.
Yes jackplate position plays a big role (IMO) in how much there boats have a tendency to chine walk. If I overtrim it starts to get a bit hairy, if the motor is too high it will start to crabwalk...which is a lot scarier than chinewalk lol.
Yes, crabbing is not fun - I'm with you on that! What gear ratio do you have in your Sporty? If yours is 1.75 then switching to 1.62 would spin the prop shaft faster, and then you could achieve the same top speed with a 26" prop as you're currently getting with your 28" prop (and less pitch creates less paddle wheel effect and therefore less crabbing).
I also wonder if making the torque tab a little thicker with some JB Weld Steel Stick would help. I made my torque tab by rolling a piece of 3" ABS pipe into the uncured Steel Stick to create the curve and I made it the full height of the skeg. That turned out to be too aggressive though, so I filed it down a bit until the steering effort left and right were about the same. I realize a thicker torque tab creates more overall drag while changing the gears creates less, but it's virtually instant, costs only $10, and can be sanded completely off if you don't like it.
Of course all of the above would only be worthwhile if more speed can be achieved by putting the motor higher up, and that might not be the case. If slip increases you could in fact lose speed by going higher (obviously).
I don't have a Merc Sporty, I have a Yamaha HPDI factory coned/lwp lower unit that I drilled to take water under the tip of the cone. 1:75 ratio. I agree spinning a smaller prop more rpm is better. Yes adding some more tab is something on my roundtuit list but when I don't have the motor too high it runs straight and true. Love your method of making a tab! The Ontario Checkmate boys should get together for a prop tester on Kushog in the fall. After labour day when the lake is quiet.
Oops ... sorry. For some reason I thought you had a Sporty on an adapter plate. Seems like I have some neurons shorted out.
Roundtuit list
- never heard that one before. I like it!doelakedog
Active member
Finished up the season with a 85 with two aboard and 87 with just me. There is more there but I need a bigger wheel. I'm still running the 27" Solas Scorpion, I am going to try the 28" when I get a chance.
Wow, that's awesome!
https://www.facebook.com/mike.ware.509/videos/10154333362595021/?l=731148382610212753
Let's see if this works.
Let's see if this works.
doelakedog
Active member
Finished up the season with a 85 with two aboard and 87 with just me. There is more there but I need a bigger wheel. I'm still running the 27" Solas Scorpion, I am going to try the 28" when I get a chance.
Nice. If I don't smash mine, you can try it sometime next year
Oh Oh... Why ya gonna smash it? I learned a few things watching my own video, I've never seen my own boat running on the pad before. Lesson one was that even though it feels like I'm trimming it to the moon, I'm not, trim is close to neutral. Rooster tail is almost non existent. IF the motor is too low, it wants to porpoise and requires much more steering input to keep it straight. In that vid I'm about 2.25" over the pad, I took a pic of the Jackplate position and I will measure it to be accurate. I am at a loss as to why these things like to chinewalk so bad, mine runs on a string. I can say the more set back I put on it, the easier it is to drive.
