Prop size for 1999 90hp Johno

[1975fflh]

Hi

I have wrecked the prop on the OB, (bloody rocky river bottoms that come up fast)(dimwitted driver, oops that was me).

The prop that was on the old girl is a 14X17 and top rpm was 5200.

Should I just replace with the same or change size, I have heard that I should run a 13 1/4 X 17.

Please help

Thanks

Gordon

[FNQCairns]

Yeah that's the one you will be happy with the result as it will give you a useable rev rang through to 5750, interested to hear if you have the time what rpm it pulls might be a little high up around 6000 but you have gotta at least try it and log the numbers IMO. Heaps around secondhand on ebay over time, cheap too!

cheers fnq

[trymyluck]

Yeah that's the one you will be happy with the result as it will give you a useable rev rang through to 5750, interested to hear if you have the time what rpm it pulls might be a little high up around 6000 but you have gotta at least try it and log the numbers IMO. Heaps around secondhand on ebay over time, cheap too!

cheers fnq


Just a few quick questions on the above prop sugestion, I have a 14 X 17 prop on a 2000 115 johnson attached to a 5m Savage Osprey Cuddy and the motor currently revs to around 5600. I'm looking at getting a new prop and keep the old one as a spare as its a bit worse for wear.
With the price of fuel at the moment will the smaller prop give better lower end grunt and higher rpm and will that result in better or worse fuel economy?
What effect would going 1 size bigger prop size have?

Thanks Mark

[FNQCairns]

Just a few quick questions on the above prop sugestion, I have a 14 X 17 prop on a 2000 115 johnson attached to a 5m Savage Osprey Cuddy and the motor currently revs to around 5600. I'm looking at getting a new prop and keep the old one as a spare as its a bit worse for wear.
With the price of fuel at the moment will the smaller prop give better lower end grunt and higher rpm and will that result in better or worse fuel economy?
What effect would going 1 size bigger prop size have?

Thanks Mark

Mark you can trade up to a 19p easily, actually higher again even, for the 19p which will make the boat new again you will need to decrease diameter possibly 13.25 or even 13.5 diameter to test.
You have bucket loads of untapped efficiency available to you. Finding a prop of the shelf that has the right recipe is the problem. Even a 13.5 ish 19p 4 blade (no cup hopefully) from solas would be ok to try.

I think you could even pull off a 13x21 BRP with some tweaking of engine height if you travel fairly light most of the time, would be fasterthan you need to travel though! cruiseing speed would be crazy efficient if it worked.

But regardless of where you do end up, 17p is too low for you but diameter will need to decrease to pull it off, that prop on your boat could tow an oyster punt -you have lots of room to move up in pitch and down in diameter to get a good result.

cheers fnq

[trymyluck]

Thanks FNQ
Second time i've written this post, don't what happened the first time:(
Would be nice to get a bit more out of the tank, not just for the $ but more range =more fishing spots= more fish. Isn't that the way it works?;D ;D . Would not mind a new 2sdi (not going to mention that 4 lettered word, don't want the popcorn coming out do we);)

Only had 4 adults on board once and the savage seemed to bog down a bit more then i would have liked with 2 down the back before it got up on the plane, mind you it was a bit on the rough side and the better half does not like rough so i didn't give it a lot of throttle.Been thinking of the Volvo ql Trim tabs but not sure if that would be overkill on a 5.5m boat.Will muck around with props a bit first i guess and see what happens.
Thanks again Mark

[FNQCairns]

Yes mark I agree efficiency is what it's all about today with the price of fuel not to mention the benefit of extra range.

Concentrate on finding a 19p with less diameter you will pull one of those off and it will put money back in your pocket compared to the one you have now and then for curiosity or fun chase up a 21 and see what happens, at least thats what I would do.

Also with the purchase of torq flo hub from merc to suit a V4 (around $100) you can fit any prop they make which can help lots considering the lack of propeller choice within any particular brand.

best of luck.

cheers fnq