prop for tabs 5m with 115 etec

[Outsider1]

Hi lamontsa,

motor height and then prop selection are very important to getting your rig performing to its best. It will help to ensure the motor is working at its optimum, and not lugging or over revving. This will help you get longer motor life, better fuel economy at cruise, good holeshot and a better handling rig overall in my experience.

Here are a few links that I think explain the variables of rigging motors and props very well;

http://forums.etecownersgroup.com/to...erado&trail=15

http://www.veradoclub.com/smf/index.php?topic=65.0

http://www.veradoclub.com/smf/index.php?topic=137.0

The E-Tec Owners Forum has a wealth of info and a number of Evinrude dealers and mechanics that can offer advice in need;

http://forums.etecownersgroup.com/mb/barnaclebill

To answer your last question first. Your wandering steering at below planing level speeds is not unusual. It could be wind or a number of other factors such as some play in your steering, incorrect motor trimming, weight distribution, or just the nature of your hull. Your motor set up may also be a contributing factor but only on the fringes would be my guess. Most boats wander a bit off the plane and are a bit tender to wind (heeling) and weight distribution and movement. Once you get your motor set up properly, try balancing your weight distribution and playing with your trim to get the best compromise.

You will see on the E-Tec Forum that the dealers seem to recommend mounting E-Tecs mostly on the 3rd hole up. You mention yours is on the top hole, which would mean it is mounted at it's lowest point. This is a link to another thread showing a motor mounted on the top hole/lowest setting (see post #3);

http://www.ausfish.com.au/vforum/sho...d.php?t=136793

I have taken a copy of that photo below and marked in red what would be the 3rd hole.

Focus on getting your motor height right first, as you may not need to change your prop. Changing props can help fine tune and personalise your set up, but you need to get your motor height right first.

Did you buy the boat from a dealer or privately? Do you have a dealer you plan to use? BRP offer a prop trail/exchange program that a dealer should be able to help you with.

Good luck

Cheers

Dave

[Fed]

You boat should go way better than that lamontsa, more like 40 knots.
All the props in the world won't help if you're not making power.
If you go to a 19" you will probably drag the revs down and if you go to a 15" it probably won't go any faster.
I'd be asking the dealer why my 115HP is only putting out 80HP, seriously.

[lamontsa]

mmm hope the engine is ok, i bought the boat 2nd hand, not sure if it still under warranty.... not that i've listened to 115 etecs before, but it sings along at WOT, no smoke at start or when running.........

hopefully just the engine being mounted too low......... (is currently set as low as it can be) from what i've read, etecs are generally most happy at 3rd hole down from top hole....

[FNQCairns]

You boat should go way better than that lamontsa, more like 40 knots.
All the props in the world won't help if you're not making power.
If you go to a 19" you will probably drag the revs down and if you go to a 15" it probably won't go any faster.
I'd be asking the dealer why my 115HP is only putting out 80HP, seriously.

What Fed wrote here could be right, there is a way too tell, do you trust the numbers you wrote above? and what is your engines gear ratio?

cheers fnq

[lamontsa]

Well fellas, i raised the engine to the third hole (from the top) as you mentioned Dave, and WOT speed is now just over 34 knots, 5500 revs - full tank fuel, 2 blokes (from 30 knots @ 5300ish). The cave plate is still under the water (should be just under or about level with water at WOT and trimmed out apparently) but much less than previous.
Thinking it may be worth raising to the last hole - Any thoughts?
I'm not intending to use it as a speed boat or doing any full speed tight turning (which may lead to the prop letting go)...........

[Outsider1]

Well fellas, i raised the engine to the third hole (from the top) as you mentioned Dave, and WOT speed is now just over 34 knots, 5500 revs - full tank fuel, 2 blokes (from 30 knots @ 5300ish). The cave plate is still under the water (should be just under or about level with water at WOT and trimmed out apparently) but much less than previous.
Thinking it may be worth raising to the last hole - Any thoughts?
I'm not intending to use it as a speed boat or doing any full speed tight turning (which may lead to the prop letting go)...........

I don't think it is going to hurt at all trying it on the 4th hole, particularly if the CAV plate is still covered, albeit just. The worst that will happen is excess cavitation I would think (which you can control by trimming the motor back in (down) in need). You still have up to 200 rpms it could possibly find, and probably another knot or two.

Whilst outright speed is not your target the closer the setup is to optimum rpms, the better cruise economy you are likely to get, plus better hole shot and also less wear long term.

What do you reckon Scott? (FNQCairns)

Cheers

Dave

[Outsider1]

One other thing to check lamontsa. There are 2 different gear ratios used in the 115hp E-tec, depending on leg length it is either 2 or 2.25 to 1. A 2.25 ratio will be slower with the same prop.

Scott might be able to calculate a theorectical top speed for you if you can tell us the gear ratio. My guess is you have the 2:1 ratio and your theorectical top speed is about 36knots (8%slip).

http://continuouswave.com/cgi-bin/propcalc.pl

Cheers

Dave

[lamontsa]

Thanks Dave,
Not sure what gearbox i have - i took a piccy of the engine plate: is this enuf info to find out what g/box i have? If not how can i find out?

Thanks

lambo

[Outsider1]

Hi Lamontsa,

the 20" long leg model has the 2:1 ratio, and the 25" XL leg model has the 2.25:1 ratio. According to the Evinrude website the DSL model numbers like yours are a long leg 20" model and so it does look like you have the 2:1 ratio.

The theoretical top speed I calculated was with your current 17" pitch prop. To go faster you would need a higher pitch prop, but you lose some acceleration. Its like putting bigger wheels on a car, you changing the gearing because the diameter is larger (the distance you theoretically travel on each revolution increases).

Lift you motor up and see how you go first. Scott (FNQCairns) will hopefully give his thoughts on your prop at opportunity.

Cheers

Dave

[lamontsa]

What Fed wrote here could be right, there is a way too tell, do you trust the numbers you wrote above? and what is your engines gear ratio?

cheers fnq

Hi FNQ,
"there is a way too tell, do you trust the numbers you wrote above?" -
What other means can i use to give me engine Revs? NMEA cable?
I also bought the boat/motor second hand, i believe the motor was sourced from a shop in Mackay, I'm in Townsville. I know there is a shop in tsv who sell/service etecs - should i be taking it there to test the power output? can they do that?

From a quick look at the prop/revs/boat speed website dave provided, it looks like the engine may be going OK with regard to producing power (5500 revs @ 34knots and leg may still be a bit low even after raising to 3rd hole)?

[Outsider1]

Hi lamontsa, a dealer can hook up his laptop to your motor and tell you the rpm history including max rpms actually achieved (when, and for how long also I think!?). This would be the best way to confirm what your tacho is telling you.

Cheers

Dave

[STUIE63]

Lamotsa it would be worth taking it to angus smith just to get the readout of engine history and to make sure it has the latest map in it talk to gary in the workshop he's a nice bloke and is switched on give me a ring as I have a couple of props if you want to play
Stuie 0438 22 55 75

[lamontsa]

Thanks fellas. I'll get the motor raised to the highest setting, give it another run, and mibbe take it to ASM to hook up to a 'puter to check out history. hopefully pick up the revs to round about 5600-5700 (on my gauge anyways).

I'll suss out the props after that thanks Stuie - I have an older style SSP - 13 7/8 17p just now, not too bad nick, may be worthwhile seeing what the newer ones can do if needbe after that.......
if i can get in the correct rev range 5500-6000 (closer to 5750 the better), then will be happy. WOT speed just now is pretty good for myself anyways.....
(took it out to burdeken rock on early sunday morning before it got too choppy, and went well thru the swell and chop, very happy so far with it!)

Thanks again fellas!

Lambo

[lamontsa]

Okey dokey,
Raised the engine to the highest position, and took out for a run. Very similar WOT speed and revs (about 5500 @ 34ish knots) to the 3rd hole. Only diff really was the motor spins the wheels a little, if not trimmed out correctly getting out of the hole, no drama really tho. So looks like i could play around with the props now? At 5500 WOT, is this gonna do any damage to the engine? I pretty sure BRP recommends 5500 to 6000 (max power/engine efficiency at 5750), so looks like it could go up a tad......... any thougths?

[lamontsa]

Okey dokey,
Raised the engine to the highest position, and took out for a run. Very similar WOT speed and revs (about 5500 @ 34ish knots) to the 3rd hole. Only diff really was the motor spins the wheels a little, if not trimmed out correctly getting out of the hole, no drama really tho. So looks like i could play around with the props now? At 5500 WOT, is this gonna do any damage to the engine? I pretty sure BRP recommends 5500 to 6000 (max power/engine efficiency at 5750), so looks like it could go up a tad......... any thougths?