Prop size

[1975fflh]

I have a 1999 90HP Johnson and badly damaged the prop (hit a rock in an unmarked part of the Shoalhaven river)at the weekend and snapped off a 4cm piece of the skeg(?) it is also slightly bent around the break off the bit under the prop on the outboard leg. (is this very important).

The current prop is14x17 can i go bigger, on either number will t make a difference, just want to get back on the water.

I did use it a bit after the hitting the rock but it lack a fair bit of power I used to get about 60klm per hour but am down to about 50klm now.

thanks

Gordon

[1975fflh]

redone to many typos need new keyboard or glasses.

[1975fflh]

Additional info
The Boat is used for fishing in lakes rivers and outside.
it is used for tubing and kneeborading and a skiing, a very good allrounder so far but a bit heavy to fish by myself.

[FNQCairns]

How come you with 90hp can push such a large diameter prop and Muzz who posted here today with 100hp cannot push even 13.5dia?

Gordon do you have the prop part number? are you sure it is 14 diameter? and what is the boat and what was your max rpm and speed. On the surface it seems you have room to move for better speed and fuel use although without a few more particulars it wouldn't even be a guess.

cheers fnq

[1975fflh]

Hi FNQ

The numbers on the prop are 14x17 and 176214

The motor model is BJ90PLEEB made 10/98 67.2kw 105.4 cubic inches.

it is a johnson made by Bombadere not OMC, Bombadere took over from OMC

I recall some time ago reading that outboard horsepower is measured differently on motors a bit older than this.

Gordon

[Spaniard_King]

I have a 1999 90HP Johnson and badly damaged the prop (hit a rock in an unmarked part of the Shoalhaven river)at the weekend and snapped off a 4cm piece of the skeg(?) it is also slightly bent around the break off the bit under the prop on the outboard leg. (is this very important).

The current prop is14x17 can i go bigger, on either number will t make a difference, just want to get back on the water.

I did use it a bit after the hitting the rock but it lack a fair bit of power I used to get about 60klm per hour but am down to about 50klm now.

thanks

Gordon

Gordon no this bit is not important. what it does is protect the prop from damage(but not all the time) just remember every time you weld the skeg of an an outboard you weaken the alluminium arround the weld (heat affected zone) so the best thing for you if you can avoid groundings and rocks is to leave the skeg as it is until you wish to sell the engine. then have it repaired and painted for the new owner. Just fix or replace your prop and all will be fine.. a bit of a bend does nothing for a trailer boat.. if your racing then it's a concern

[FNQCairns]

Hi FNQ

The numbers on the prop are 14x17 and 176214

The motor model is BJ90PLEEB made 10/98 67.2kw 105.4 cubic inches.

it is a johnson made by Bombadere not OMC, Bombadere took over from OMC

I recall some time ago reading that outboard horsepower is measured differently on motors a bit older than this.

Gordon

Well what about the move to a 18p? you will need to go down in diameter which will not make a negative difference worth considering compared to the potential benefit, but everything depends on where you are ATM...or where you were before the accident.

To be sure or to feel at least confident enough to warrant the cost risk a person would need to know the boat and max rpm and also that the leg height was at least in a ballpark position.

cheers fnq

[1975fflh]

Thank you Spaniard King and FNQ you two have saved me heaps of money and embarresment since I joined.

FNQ-The prop that was damaged was because I was in brakish water and it runs into shallows very fast without a noticable mark on the water surface and I was moving at about 30klms when we hit bottom with the motor I am normally more careful.

The prop was on the motor when i bought the boat i thought it was original.

I gather the 18 P is the second number as in 14x 17 17 is the P?

I am looking on ebay and have sent an email to FNQ outboard wreckers looking for a suitable prop FNQ wreckers have been helpful on a couple of occasions and do not overcharge like our local shops etc in Wollongong or Sydney.

What size would you suggest as it is all chinese to me in regard to props pitch and size?

Thank you

gordon

[FNQCairns]

Hi Gordon, still dunno what RPM you are hitting because if up high already it complicates things.

If you have room to move up in rpm (those engines live long with high revs) look for 13.5 or even a 13.25 X 18p all will depend on where you are ATM. The diameter is the first and the pitch the second.

In truth and depending even a 13x19 could work, testing sorts the wheat from the chaff. diameter becomes too small when the driver decides it is so you have a few options, the 19p is a little outside, so depending on what you find for sale etc. hopefully a prop more or less the diameter of the ones above will not be too hard to find.

cheers fnq

[1975fflh]

At the moment full throttle I get 5200 rpm with the 14x17 and about 60klms.

I will have to dig out the owners guide and have a read, I dont know what they are supposed to run at, I read somewhere it was 5200rpm.

So I will search around for a 13.5x18 prop and see how it goes, Hope theres one on that dreaded auction site cheap.

Thanks for the help.

Gordon

[1975fflh]

FNQ would a 13X19 in stainless be ok