what size prop do i need?

[wishiwasfishin]

i have a triton 176 mag with a yamaha 115. i am having trouble with the
prop loosing "bite" and the rpm reving up. my dealer removed my jack plate and installed a laser II 20p prop. we ran the boat a couple of times
and had the exhaust ports plugged. the boat runs better, but still looses
"bite" in turns and during slower speeds while on plane. also, motor is maxed out at 3/4 throttle and will hit 6000rpm by boat rpm gauge.

am i expecting to much from an aluminum boat. can be a little hair raising when you go into a turn and the prop looses "bite" and you keep going straight. i had a glass boat before this boat.

anyone else have a triton or experienced this before??????

[1FASTLASER]

First off welcome to the forum. Second why did the dealer remove the jackplate. That makes NO SENSE AT ALL. In fact he did exactly the wrong thing to do, considering you probably only needed to drop the plate a tad bit to stay hooked up. I would be raising seven kinds of hell. You definatley need to put that plate back on and tell your dealer he dont know chit bout boats. Very likely all you need to do is trim under a little in turns. I have to do this as just about every other person running a plate on a light boat. Its just the nature of things. I would also say you have lost some performance on your rig. Let me know what you decide. That just blows my mind a dealer would do that. Got my blood boiling.

[1FASTLASER]

I'm sorry for double posting but this is exactly the reason I have learned how to work on these rigs. Dealers like that should be HUNG AT NOON. Please excuse my ranting. Put that plate back on and give me some numbers and I will help you get your rig set up to run the best with what she has. I need WOT tack readings, GPS speed, what the measurement of the center of propshaft is from the center of the pad. To do this when on the trailer level the boat at the rear of the pad, then lower the motor till when placing a level on the cavitation plate the motor is level. Then take a measurement form the center of the propshaft (the point on the lower unit....the point of the bullet so to speak) and the bottom most point of the pad. Another good numer I can use is the time it takes to get on plane and the rpm's when you first nail the throttle. With these numbers I can get you real close to the optimum setting with just a littlwe trial and error on your part.

[zooker]

needs to go up at least 1-2 pitch. your bumping the rev limiter.. mine did the same thing with the 13p aluminum prop went to a 14p ss it stopped bumping it.300 less rpms and 4 mph faster..

zooker

[1FASTLASER]

WISHING Did ya ever get your prop problem figured out. Would like to know if ya need anymore help and would really like to know if ya put the plate back on. Let us know.

[wishiwasfishin]

laser i have not had time to take back to shop. have been to busy with work and fishing. going back by shop in the morning.

the jackplate was as far down as it would go, that is why they took it off. do you know what size prop triton recommends on a v176 with a 115hp yamaha? would a 21p or 22p be too big?

on the positive side caught half a dozen 3 and 4 pounders with a 7.5lb kicker that my 12yr old son netted for me sunday. cant beat days like that with your son.

[1FASTLASER]

Ok here is the solution that I recommend. First of get that plate put back on. The starting place for the height adjustment on your boat will be 2" from the center of pad. Doing this will be a BIG plus in performance. To measure correctly with boat on trailer you may have to jack the trailer up and put something under the tires so you can trim down far enough. After getting the trailer where you can do this level the boat by putting a level on the pad closeest to the rear. After getting the pad level trim your motor under till its level with the level sitting on the cavitaion plate (the plate just above the prop). Oh forgot you can use the trailer dolly to level the boat. After getting the boat and motor level measure from the propshaft center (the point on the bullet lower unit to the center most part of the pad. On high performance boats you can start at 1 1/2"'s below pad. On smaller boats I start at 2" below pad and work from there. As far as prop pitch when using a jackplate you will be able to spin a taller wheel enhancing performance. From your previous post you said you where hitting 6000 @3/4 throttle. That indicates to small a prop. Normally you will be able to run a 23p with no problems but remeber that every boat is different. Theoretcally you should be pulling hard to 5500 rpms with a prop give or take a little. I would think a 22 would put you right where you need to be with a little effort on your part running the plate up or down small increments at a time you should be able to find the sweet spot. Let me know what you decide to do and I will help you get the best outta your ig.

[zooker]

21-22 would be a good starting pitch.23 would be middle road -a decent hole shot and decent top speed something in the low to mid 50's. if ya get high 50's to low 60's for speed odds are your hole shot will plum suck..

zooker