Jump to content
Sign in to follow this  
dragline

Jack plate on pcs

Recommended Posts

I have a 91 pcs with a 93 mariner 2.5 efi 200.Im turning a merc 30 pitch clever at 6700 rpm.Im 1 3/8 inches above the bottom of the boat (with a 5 inch jack plate).The boat gps at 92 mph.After reading the article about pcs,s can run 3 to 5 mph faster with out the jack plate ,how much speed would I pick up if any running only a 200hp if I removed mine?Also if I remove the jack plate will I have to lower the motor a tad?

Share this post


Link to post
Share on other sites

Sounds like your boat is running perfect already with only 200hp. I would leave it alone as I am not sure "the remove Jackplate" principle will apply with 200 hp.

Lets here RT's comments with 200 Hp

Your prop efficiecy is a little low at 87% based on your numbers and assuming a 1:87 Gear.

I usually get 87% efficiency with another person sitting in the front seat. Your engine ht is exactly what I use

THANKS for posting!

Share this post


Link to post
Share on other sites

I am going with Anthony on this one. You I am gonna say do not have enough power to get the boat to reach the point of flattening out. I would also consider trying a 30 chopper II as opposed to the cleaver. Your speed is about right, but I think with a little more set up you could get to 95. I cannot remember where the rev limiter is on that motor, but I would pull the revs back to under 6500, as you arn't making any power. A few mods and you are not far from 100, at that point I would remove the plate.

Hope that helps a bit.

RT

Share this post


Link to post
Share on other sites

Rob, a chopper II?  You guys always swear by the 14-1/2 x 30 Merc Lab Cleaver.  Curious to the suggestion this time.

Wouldn't the chopper give you too much bow lift at that speed?  Thanks.

Share this post


Link to post
Share on other sites

BRAD,

I have driven the ChopperII (28P) on a Vking Hull with 200 Merc.  I must say that the handling is much improved over the old choppers and I kind-of liked it!

I have not tried it on the STV, however I am not likely too, as I am still a fan of the 14.5 x 30 Merc Cleaver with the 240HP I currently run.

Remember I have used this 30 cleaver prop with as little HP as 150 on the STV and it netted a respectable 62-6400 RPM with a 2.0:1 Gear.

Had the Chopper II been around then, it may have been a good candidate for a little extra bow lif,t when driving with a passenger, as the 30 Cleaver did struggle a bit, in the bounce zone, for lift with a 150 HP.

So with 200HP, the Chopper II may be good to try if you have the chance.

Share this post


Link to post
Share on other sites

Thanks for the input ,I will leave the jack plate on . yes I have 1.87 gears,and actuallythe prop Im runningis a lightning et,so it is getting the nose up .After rigging the boatand listening to your advice,the boat has gained 7 mph for minimal money,not to bad!I do appreciate the help!!

Share this post


Link to post
Share on other sites

HEY DRAGline,

I love to hear those mph gain storys...GLAD to help....Just keep asking!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×