question about RPM's and T&T J50BELCDE

[Freebo]

Gentlemen, took "Big Ugly"(1985 16ft Starcraft w/front and rear homemade casting decks (heavy)) out Saturday and w/ my GPS clocked it on smooth water @ 31-32mph @ 5600 rpm's at Full Throttle I'm not sure what the "norm" for this motor is.. (that is my first question). My motor does not have Power T&T I know that I should gain a few MPH by adding that, what would be my best choice finding a used Johnson/rude T&T motor or adding a aftermarket? Thanks for any suggestions. OH.. by the way.. I can't find the Pitch stamp on the prop i'm using.. my second prop is a 12 1/4 X 15 (what is that one designed for?)

 

[steelespike]

Re: question about RPM's and T&T J50BELCDE

I believe your motor developes its horsepower at 5,500 rpm so I think you are in range but someone should be along with more info on that.<br /> Have you adjusted the trim and what were the results?Have you moved weight around for the best trim.Too much boat in the water will slow things down.Check the virticle height. Anti vent plate should be about even with the bottom of the boat to start.Then raise the motor a little at a time virtically until just before ventilation becomes a problem.Be sure it continues to cool.If there is room to go up an inch you could get about 3 mph increase.<br /> While tilt and trim is very nice you are talking a bunch of money.I would try getting things trimmed up as you are.I can't tell you much about your prop but why not give the second one a try?

 

[Freebo]

Re: question about RPM's and T&T J50BELCDE

Spike, I don't want to sound like an Idiot (living as one is hard enough) but describe the anti-vent plate for me? I havn't gotten my manual yet... CFREE

 

[Boilermaker]

Re: question about RPM's and T&T J50BELCDE

Freebo,<br />The anti-vent. plate is the horizontal area just above the prop, cast into the lower end of the engine.<br />I am NOT one of the experts here, but it seems to me, your doing pretty well as far as speed & Rpms goes. How is the performance in the midrange & your holeshot???<br />> As far as your "second" prop, if it looks to be in good shape, no big nicks or bent, give it a try. There should be a number stamped or cast into the hub, near where the shaft is. OR at the root of one of the prop blades. <br /><br />Are the props the same design???from the same manufacturer???

 

[Freebo]

Re: question about RPM's and T&T J50BELCDE

Bmaker,<br />So the AV would be where the Whaletail is attached.. I'm going to check to see how it's set up tonight when I get home. I'm Off this Friday so I can take "Ugly" out and play around w/ her. My performance is fine all around. I just figured to start looking for a power T&T to add to the motor. and my initial question was just to see if I was in Range w/RPM. <br />The 12.25x15 (Alum) is (from what I'm told) is the original prop for the motor..the other is a painted Stainless (having trouble finding the stamp on it..) Looks to be the Same Diameter as the 15. I'll holler back w/ how it is set up tommorrow. Thanks Guys

 

[Freebo]

Re: question about RPM's and T&T J50BELCDE

the AV is set up about 1/4 inch above the bottom of the boat... one hole up would take me about 1-1/4 above... I belive i'll just leave it like it is and continue my hunt for an affordable way to add T&T to the motor...that should add a few MPH to her top end...I might try out the other prop on Friday and see what she does..

 

[Freebo]

Re: question about RPM's and T&T J50BELCDE

Does anyone have the correct PN; for the OMC Tilt and trim to go on this motor? Thanks

 

[Boilermaker]

Re: question about RPM's and T&T J50BELCDE

Freebo, at the top lefthand part of the page, just under "BOATING FORUMS" is a lines that says "Shop Iboats"...there is a section for tilt/trims. Its a place to start!<br /> If your looking to improve your top end speed, you might want to rethink having a whaletail/hydrofoil adding drag to your motors lower end.<br /> Do you have holeshot issues or planing issues that you are trying to remedy with the tail???

 

[Freebo]

Re: question about RPM's and T&T J50BELCDE

BM,<br /><br />It was on there when I got the boat the previous owner said that it made the world of diffrence getting up on plane...I took him at his word and havn't messed with it..I have looked at the Panther aftermarket Tilt and the CMC just don't have the moolaa at the moment to indulge myself.. I'm going to play around w/ the Tilt Bar Settings tommorrw (i'ts all the way down right now) and see what the results are.. i'll follow up Thanks