77 VMATE I 90hp Perf. Question

[FASTER]

Brand new to site. looks great! Have a 77 V-MateI w/Johnson 1988 SPL88(90hp) w/ Power Trim & Land & Sea Hyd. Jack. Turning 19"at5600 w/jack at mid.53mph(speedometer) How much could I expect to increase my speed if I replace with a 1988 140hp power head? Really looking for 60 if possible. THX!!

[FASTER]

Brand new to site. looks great! Have a 77 V-MateI w/Johnson 1988 SPL88(90hp) w/ Power Trim & Land & Sea Hyd. Jack. Turning 19"at5600 w/jack at mid.53mph(speedometer) How much could I expect to increase my speed if I replace with a 1988 140hp power head? Really looking for 60 if possible. THX!!

[boatman4021]

Faster, I hate to be the one to tell you, but your speedo is way off. If you do the math(rpm divided by gear ratio x pitch divided by 5280 x 60 divided by12), you get 50.37mph. Depending on your prop, you can deduct 8 to 12 percent from that for slippage. The best way to get actual speed is with a gps or radar. You said you have a 19" prop, but what brand is it and is it aluminum or stainless steel? boatman

[FASTER]

Thanks for the reply! I had a feeling my speedo was off. I'm running a stainless 3 blade and wouldn't you know that a took a gps out with me 2 hrs ago and at full trim just before the chine walk started I was getting 50.1! I'm wondering what pitch I could turn if I changed the block from a 90 to a 140. Thanks again for the reply.

[boatman4021]

WOW! That's great. One thing's for sure, you can always go faster with a bigger motor. What kind of prop are you using? Is it stainless, or aluminum? boatman

[FASTER]

Believe it or not, it's actually a Cabelas Stainless Steel 19" I got a pretty good on it from a friend of mine.($150.) It behaves much like a OMC Raker. The only problem is the last 3 mph is developed when trimming up all the way forcing the bow right up there. This is when the chine walking starts and I have to back off, or trim down. I have always had deep V hulls. This is the first checkmate I've had. I think I'm hooked on them.

[daren34]

i don't think you have a pad but you still should see 60 plus with a 140 powerhead

you may need to raise the motor up higher

get a water pressure guage and crank it up



i had a diplomat with a 140 22 pitch raker at 6300 rpm on a 6 inch hyd cmc
no chine walk

it would roll down off of the pad then roll back up on it though

good luck daren

[daren34]

that v-mate should be lighter than the diplomat was you should go faster if you can lift it high enough

daren

[boatman4021]

Faster, How would you like to try an aluminum prop that could make your boat a little faster with less chine walk, less trim, and handle better at all speeds? It can be done! boatman

[FASTER]

Thanks for the input Daren. Yeah, water pressure guage is next on the list. My Jack will raise the motor until it blows out I then lower it a tad and then she bites and lifts. I was actually dissappointed w/ the 50mph. I'm sort of new to the checkmate hull. Last boat was a 1989 Cobia 19'Cuddy with a 1989 Johnson GT 175 and that same Land& Sea Hydraulic Jack. I rigged it myself in 1989 as I worked at a Marina then. That boat used to really wail! Especially on the ocean. Hull weight was only 1300lbs. if you can beleive it. Extremely stable. The checkmate however is a totally new feel. Quite frankly, I'm still a little shy about cranking this thing into a really tight high speed turn. I don't know about other checkmate models but this boat like to "flip" way up unto its side during a tight slower turn. Kind of freaked me out at first. Higher speeds it doesn't do the flip thing but it's alway on my mind if it does 'cause I don't want to go over! You ever have experience with that?

[FASTER]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by boatman4021:
Faster, How would you like to try an aluminum prop that could make your boat a little faster with less chine walk, less trim, and handle better at all speeds? It can be done! boatman </div></BLOCKQUOTE>

I'm all ears boatman!

[jgreen]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I think I'm hooked on them. </div></BLOCKQUOTE>

I think we all are!! http://www.checkmate-boats.com/infopop/emoticons/icon_biggrin.gif

[boatman4021]

Faster, Send me a private message with a phone number so we can talk and I will HOOK YOU UP! No strings! boatman

[daren34]

land and sea used to make a 185 horse v-4 ski motor

that was a few years back

the last v-4 i had on my diplomat was a 88 or 89 2.o litre looper

had to use a jack plate to cure the chine walk


daren