Jack Plate for 50hp

[bass4brains]

Any advantage to adding a jack plate to a 15" cobra with 50hp? I'll probabily have to build it since I've not found a commerical one for that engine. Or would the extra weight out weigh any advantage? Just stripped 85 pounds of 1" pressure treated plywood that had just been laid on top of rotted floor and front fishing deck, & replaced floor and deck propperly. But I'm still only getting around 25mph by G.P.S.

 

[WillyBWright]

Re: Jack Plate for 50hp

Make sure you have good compression and that both cylinders are getting spark. You should get into the lower 30s. But that's about all. That's not a particularly fast package no matter what you do with it short of finding a motor that atually makes 50Hp.

 

[roscoe]

Re: Jack Plate for 50hp

That's not a particularly fast package no matter what you do with it short of finding a motor that atually makes 50Hp.

Or perhaps 75 hp.

 

[bass4brains]

Re: Jack Plate for 50hp

Yea I been thinking about a 70 or 75hp would be the best fix! Forgot chysler rated theirs at the crank and not the prop when I bought the boat. Are the mercury mades rated at the prop? Or are they the same ? Although I've read they don't hold up as well as the chysler models.

 

[Frank Acampora]

Re: Jack Plate for 50hp

I had an old 55 on a 15 foot Glastron. It did 27 MPH. You are getting just about what would be expected from your engine. You might be able to squeek out a few MPH more with a jackplate, but if you intend to ski or tube, the 50 is just not going to satisfy you. If the boat is rated for more, the best option is a larger engine. My Glastron is rated for 90 and even an old 90 Chrysler made a world of difference. 38 MPH and now the boat could easily pull me out of the water.