prop and tach. question.

[texas_angler_2002]

hi,<br /> thanx for repling but i have a 1985 procraft boat with a 115 v-4 evinrude motor.it will ride with the bow up for a good period of time and yes i do have a plaing fin on it. i was wondering if the prop is too big for it or is it just lacking power. the props size is..13 1/4 x 17....too big or just right.<br /><br />2nd question:i am hooking up a new tach. and it had a factory tach. in it so i have to cut the wires and now on my new tach. it has a place for wires to go to.....ign......ground....sending.. the wires i have are purple black and blue....also what setting does it have to be on... 2p/4c....3p/6c....4p/8c.....5p...6p<br /> thanx for ur help.

 

[clanton]

Re: prop and tach. question.

You are missing one wire for the tach. Purple for power, gray for signal, black for ground, blue for light. Setting probley 6p. Blue could be tach sender for this boat, you should trace gray tach wire from engine.

 

[texas_angler_2002]

Re: prop and tach. question.

when i cut the wires they were wired in the inside and there was only 3 wires . i was wondering what color wire if there was one for the light.

 

[clanton]

Re: prop and tach. question.

Most of the time blue would be for the tach light, but I think the boat builders just use whatever wire is handy. This boat may have a master switch and engine switch. Sometimes the tach power comes from master switch, which means both switches have to be on for tach to work.

 

[texas_angler_2002]

Re: prop and tach. question.

thanx clanton for all the help but can u explain the bow riden up for a long period of time

 

[OBJ]

Re: prop and tach. question.

Texas....couple questions....where is the ventilation plate as compared to the keel of the boat, ie...below, even or above? Do you have trim and tilt. You didn't give the year of the motor so we don't know if it is equiped with trim/tilt. If you do have TNT, do you use it? What kind of RPMS do you have once the boat planes out? I know the questions may sound strange but they all could have bearing on how your boat performs.<br /><br />Jim

 

[rons boat]

Re: prop and tach. question.

The boat should come out of the hole and stay there on plane if it is trimmed right. Make sure the bottom of the motor is pulled in further to the stern if the bow rides too high. When your tack is fixed and the thing is working it will tell you if your pitch on your prop is right. Most big non planning boats tend to use a 15 or 17 pitch. Fast and light planning boats go up to 21 or so. If your boat at WOT meets the spec for your motor about 5500 rpm the pitch is right. If you get too much revs then you are too low and need to increase pitch....not enough revs can be caused by too big a load, a boat not trimmed properly or a pitch of the prop too high.

 

[texas_angler_2002]

Re: prop and tach. question.

the year of the motor is 85 rude and yes i have tnt and if u are refering to the vents that let the fumes out they are on the side of the boat and frankly i am a new boater and i have no idea how to use tnt that could be my whole problem,.

 

[Jim@KSC]

Re: prop and tach. question.

texas_angler_2002 -<br /><br />Most boats like the 'up' position best for speed and economy.<br /><br />Get on a plane, at any speed, but not wide open or dragging. Raise the trim until one of two things happen...<br />Porpoising: the bow will start to bounce and get more radical.<br />Ventilating: RPMs will rise dramatically and you will hear increased exhaust sound.<br /><br />When you get there, back off a bit until the above stops. That should be your best trim.<br /><br />It doesn't have to stay there. The quickest way to a plane is with the trim all the way down.<br /><br />Once you get familiar with the trim, measure wide open throttle (WOT) and return here for the experts. If the tach gets too tough, try TinyTach for a good aftermarket solution.<br /><br />Good luck!

 

[OBJ]

Re: prop and tach. question.

Texas.....<br />The Ventilation Plate is the "Fin" right over the prop. This sort of keeps the water down on the prop to prevent cavitation from air intrusion. Jim@KSC got ya' on the right track as to the operation of the TNT. After a while playing with it (the TNT) you will know just where to put it (this just keeps gettin worse) for best performance from your boat. Just pay attention to the trim gage and tach and you'll become an old pro.<br /><br />Jim