prop masters or boat mechanics

Braun · #1 04-14-2011, 11:18 PM

any prop masters or boat mechanics here? having some prop questions on my project boat

Kokanee9 · #2 04-14-2011, 11:36 PM

http://www.mercurymarine.com/propellers/prop-selector/#

Braun · #3 04-15-2011, 12:06 AM

thats a sweet site but the years only goto 2000. lol.

it asks if you are at a high altitude. what difference does altitude have on the type of prop you use?

npauls · #4 04-15-2011, 12:13 AM

Altitude is huge on how your boat will run.

I have been told if I take my boat to the coast I could run a 17 pitch prop and hit low 30's with it where as the lakes around here I run a 12 pitch and hit 26mph if I am lucky

Braun · #5 04-15-2011, 12:20 AM

right. but i see that effecting how your mottore runs. not how the prop performs

chubbdarter · #6 04-15-2011, 12:24 AM

most hp ratings are based on sea level....higher you gothe less hp you have.....prop ajustment has to be made according to horsepower...and other things but thats the simple explaination

Braun · #7 04-15-2011, 12:32 AM

k that is what I thought. it also depends what qualities you want....... im learning alot with this project.

Kokanee9 · #8 04-15-2011, 07:09 AM

The guys who run the sleds in the high mountains could tell you more about this. It has something to do with the air/fuel mixture. High alt = less oxygen. I don't think it has anything to do with how the prop works, it's the power to turn the prop. Maybe just run with what you have and see how that works and then adjust from there if you need to.

Braun · #9 04-15-2011, 07:46 AM

That's the plan..... If I can get all the parts sorted out and get the prop on and turning. I'm worried about the amount of play in and out that I have.I can pretty much role my shaft over the hearswhen turning the prop clockwise by hand. Or pull out the shaft a but then it clears the gears when turning it by hand in the other direction

Kokanee9 · #10 04-15-2011, 08:07 AM

Quote:

Originally Posted by Braun

That's the plan..... If I can get all the parts sorted out and get the prop on and turning. I'm worried about the amount of play in and out that I have.I can pretty much role my shaft over the hearswhen turning the prop clockwise by hand. Or pull out the shaft a but then it clears the gears when turning it by hand in the other direction

Not really sure what your talking about. When this fresh batch of snow is gone, give me a call and I will check on my boat what your getting at. What I think your getting at is - if you pull outward on the shaft, it will turn in one direction. Is the boat in neutral or in gear? Try changing it from forward to reverse or put it in neutral and see if it does the same. Maybe that's the way they are made. Not a marine mechanic, so I don't know for sure. Remember when the prop is turning in the water, it is pushing forward on that shaft.

Braun · #11 04-15-2011, 08:48 AM

no. lol i told nate this is hard to explain. ok. so my prop shaft has alot of play in it (not side to side play but in/out) when pushed in all the way it engages the gears and if i try to turn it by hand while its in gear, the prop does turn. thats a really good sign because it means that the gears in the lower leg are fine. But here is where the slop comes into play. there is enough slop where i can pull the shaft out (dont have to pull hard. just lifting the weight of the shaft) and spin it in whatever direction without it contacting the gears.

this just doesnt seem right that the shaft would be that loose. Like is said my prop isnt bolted on yet because i know I am at least missing the thrust washer but i think i may me missing a couple parts that go on even before that. it will be handy to have that manual that a awesome AOF member is sending me.

Kokanee9 · #12 04-15-2011, 10:18 AM

Quote:

Originally Posted by Braun

no. lol i told nate this is hard to explain. ok. so my prop shaft has alot of play in it (not side to side play but in/out) when pushed in all the way it engages the gears and if i try to turn it by hand while its in gear, the prop does turn. thats a really good sign because it means that the gears in the lower leg are fine. But here is where the slop comes into play. there is enough slop where i can pull the shaft out (dont have to pull hard. just lifting the weight of the shaft) and spin it in whatever direction without it contacting the gears.

this just doesnt seem right that the shaft would be that loose. Like is said my prop isnt bolted on yet because i know I am at least missing the thrust washer but i think i may me missing a couple parts that go on even before that. it will be handy to have that manual that a awesome AOF member is sending me.

Wasn't sure what year so I guessed at 72.

http://www.crowleymarine.com/mercury...hp/MERCURY.cfm

http://www.crowleymarine.com/mercury-outboard/454.cfm

http://www.crowleymarine.com/mercury...rts/454_17.cfm

Braun · #13 04-15-2011, 10:27 AM

ya i dono. im starting to think my best option is to drag it to a marine shop and let them just tell me what i need and open up the wallet. I really dont want to have to take apart the entire gear assembly to figure it out.

Kokanee9 · #14 04-15-2011, 10:36 AM

Quote:

Originally Posted by Braun

ya i dono. im starting to think my best option is to drag it to a marine shop and let them just tell me what i need and open up the wallet. I really dont want to have to take apart the entire gear assembly to figure it out.

I wouldn't take it apart either. If you dig into the diagrams, there should be one with the stuff right behind the prop. I didn't pick those particular ones to encourage you to take it apart, just an interim measure until that manual is in your hands.

I learned my lesson about taking things apart on a dishwasher once.

Braun · #15 04-15-2011, 10:45 AM

lol i take things apart with comeplete disregard. half the fun is remembering how they go back together. i know what you meant by it. but those diagrams can get you even more confused thats why i was hoping someone on here might know a thing or two about my situation

Gust · #16 04-15-2011, 01:32 PM

Quote:

Originally Posted by Kokanee9

Not really sure what your talking about. When this fresh batch of snow is gone, give me a call and I will check on my boat what your getting at. What I think your getting at is - if you pull outward on the shaft, it will turn in one direction. Is the boat in neutral or in gear? Try changing it from forward to reverse or put it in neutral and see if it does the same. Maybe that's the way they are made. Not a marine mechanic, so I don't know for sure. Remember when the prop is turning in the water, it is pushing forward on that shaft.

I've been trying to understand this too,, on our 90hp Yamaha but much newer and on salt water, if you ran over a small log, the motor would kick into neutral and disengage the thrust, for lack of proper terminology. It could be a gear saver. Can you post the serial number from your motor and I'll write to a marine mechanic friend.

Braun · #17 04-15-2011, 01:48 PM

ummmmmmm ya i guess. wont be able to do it till tomorrow though. at least its good to know that im not the only one on this. maybe what i got is normal and just no one else notices it. im actually having trouble getting my prop on. i know its got the right amount of teeth and ive cleaned it all off but it is just ridiculously tight. with a little rubber persuasion it goes on. and seems to go on easier and easier every time but it shouldnt be that tight. Same issue with both my props.