Stainless propellers

[wastewaterguru]

I have a 115 Yamaha 4-stroke on a Lund 1700 Fisherman and am fed-up with aluminum props. I spent a lot of time on the rivers the last couple years and have spent more than $200 in prop repair. All of the rebuilds have been a result of minor impacts with sticks and debris. I want to upgrade to a stainless but have no clue what pitch and diameter to go with.

If anyone has a similar boat/motor combo with a stainless prop, I would appreciate some information on prop manufacturer, performance, and durability. I currently run a 13 and 1/2 inch by 19P Michigan wheel aluminum for fishing and a 13 and 3/4 inch by 15P for water skiing.

Anybody have some good thoughts on what would be the best prop for both situations.

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I fish.....Therefore I grovel.

Here....Fisheeeeeeee!!

[kjgmh]

I would recommend a Mercury Vengance or Laser 2 stainless. It will be approx $450-500. Without knowing what rpm you are turning at full throttle I don't know what pitch recommend.

[This message has been edited by kjgmh (edited 03-07-2003).]

[marine_man]

wastewaterguru,

Can you tell me what you're turning for RPM with both props? This is a big consideration in propping out a boat... and if done correctly should eliminate the need for a running prop (speed prop) and skiing prop (power prop).

One consideration though... if you're doing enough damage for prop repair to total 200 dollars I don't know that I would consider a stainless steel prop. When you hit something with aluminum, as you already know, the prop deforms. When you hit something with Stainless steel the prop doesn't typically give, forcing the lower unit on your motor to give, typically causing damage. In my opinion, I'd rather have a prop rebuilt from time to time than paying for a new lower unit... but again, that's my opinion.

[wastewaterguru]

The problem with the aluminum props is that they "weld" pieces to the prop to fix the damage. Once you have one rebuilt for the first time, they tend to "melt" away at the leading edge of the repair area and even hitting twigs at the thin "melted" area causes the entire repair area to fail. I have also noticed that I can flex the blade that has been repaired with my hand and I know that aint helping the performance any. I still plan to use an aluminum prop on the minnesota river because the current is fast enough that large logs, etc. remain near the surface even after they are waterlogged and denser than the water.

With the 19P prop I get about 43 mph at 5500 rpm. The 15P prop I do not get to WOT. I get to 5500 rpm before WOT at about 36 mph. I never go faster than 30 when tubing or skiing so I don't worry about the rpm's much on this prop. The 15P prop has a much greater initial accelleration, but I do have to pay close attention to the rpm's.

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I fish.....Therefore I grovel.

Here....Fisheeeeeeee!!

[swampman]

I wouldnt be afraid of going to a stainless prop because of lower unit damage although its a concern. when i was in the bait buisness we switched to a stainless prop on our 30 hp yamaha never regretted it and that thing did take a beating. we also never had much luck rebuilding the aluminum props, seemed like the water was enough to wear them away.We still had the same ss prop on the motor when we sold it after 10 yrs, and it was on the water at least 5 days a week during the open water season.

[marine_man]

If I had to guess.. and this is only a guess mind you... I would probably try a 19 or 21 pitch prop... leaning more toward the 21 pitch prop. You're best bet would be to find a dealer (or take it back to the dealer you bought it from) and try both props to see what you get for performance.

Also, Yamaha's recommended RPM range is up to 6,000 RPM. 5500 is the typical limit on a 2 stroke, but most 4 strokes (including yours) run out to 6000 RPM. That's why I'm guessing at a 19 pitch prop to get your RPM up. Stainless steel props have more cupping than aluminum props, which is why you typically need to add 2 - 4 inches of pitch.

[Kevin Turner]

How about a removable prop gaurd?

[wastewaterguru]

Kevin....are you talking about the "ring" type???? Got any specifics?

More cupping and more pitch......wouldn't that lower the rpm??? More resistance.

I am really hoping that someone with a similar motor/boat setup can provide some "real" data. I have found that the dealers don't like the idea of loaning out $400 props to play with. Anyway, I appreciate all the info. Hopefully some Yammy/Lund owners can chime in with some help.

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I fish.....Therefore I grovel.

Here....Fisheeeeeeee!!

[This message has been edited by wastewaterguru (edited 03-07-2003).]

[marine_man]

Bear with me for a minute here.. I'm starting to dig deep to remember everything about propping.

If I remember right, the cupping is done such that you get a better hole shot (which implies a flatter blade) and yet get a better top end perfomance (which implies a more curved blade). While working for a marine dealer, it was not uncommon to see a dramatic increase in speed (5-7 miles per hour) while also getting a big improvement in hole shot. All of this typically requires a increase in pitch of prop to keep the RPM where it should be.

I hear you on looking for "real" data... I would suggest contacting a dealer and see if they've recently propped the same setup as you have with a Stainless prop. Talk to someone in the service / rigging department.. salesman typically don't know anything about propping.

[Kevin Turner]

I'm not up to speed on prop gaurds, but I was on another site an there's a thread with photos and feed back. If you like, I can e-mail the site.

[This message has been edited by Kevin Turner (edited 03-07-2003).]

[wastewaterguru]

Kevin, you can email it to [email protected].

Thanks for all the info guys. I love this site. I'll get on the phone one of these days and see what I can find out. I imigine the riggers are being kept pretty busy this time of year, but hopefully I can get some help

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I fish.....Therefore I grovel.

Here....Fisheeeeeeee!!

[Guest]

When getting the proper prop for a rig, dealers of your boat make should be able to set you up with the recommended props for your boat and power. The will have tested the various props for your engine and boat.

Be very careful about props because you can over rev an engine with the wrong size and pitch.

Those of you think your dealer is an one-who-thinks-I-am-silly and doesn't know anything about boat rigging are idiots yourself for buying from an one-who-thinks-I-am-silly.

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Kevin Neve's Devils Lake Guide Service
fishingminnesota.com/kevin-neve-guiding/
e-mail: [email protected]
Phone: 701-473-5411 or 701-351-4989
Minnewaukan ND

[This message has been edited by kevin neve (edited 03-07-2003).]

[kwkfsh]

Waste, if you are satisfied with the performance of you alum. prop you can use the same pitch and you will have virtually the same performance and rpms. Cupping is not related to material in any way shape or form, either can be cupped or not. The notion that a SS prop is harder on the lower unit is a fallacy, as all newer O/B's have a hub that slips or shears on impact. Each 2" of pitch you go up or down will change you WOT rpm approx. 400 rpm.

[Fishbitten]

As said in last post if your rpms are satisfactory, holeshot etc. go with 17 inch ss because unlike alum. ss will not flatten out thus reducing it's pitch. P.s. cup does matter if you get a prop with a lot of cup 15" may not be out of the ?