Topspeed ??

[Member Removed]

I just cant get my Warrior 165 with a Suzuki DF 70 to run more than 30 knots - with 2 adults and a full 25 litres tank. Ive hoped for 32-33 knots.

 

The prob is 13,5X15 and rpm is 5900-6000.

 

A friend of mine has got a Warrior too ( with a Honda 50hp) and the topspeed is 28,5 knots under same conditions.

 

20 hp should give more than 1,5 knots !!!

 

I just dont understand it !

 

 

Onslow

 

 

 

 

 

 

 

 

[Mike Fox]

Is his hull polished, and is yours fouled with barnacles etc ?

 

Mike

[blueboatdriver]

What size are his adults?

 

If I could get up to 30knts I don't think another 2 would worry me too much

[Member Removed]

We are both trailering our boats so both hulls are clean. The Suzuki feels more powerfull, especially under accelleration. But 1,5 knots is not much with an advantage of 20 hp.

 

 

 

[Maverick Martin]

Onslow

 

I have just looked at the Suzuki site and the operating maximum rpm for the DF70 is 5200-5800 so at 5900 you are slightly over reving which might suggest you need to either have your current prop re-pitched a little or a slightly larger prop.

The effect of both the above would be to give you slightly slower acceleration but more top end. Take advice from you local prop specialist, he will be best placed to advise. Over reving by just 100rpm isn't major but it would make a difference to performance.

 

Another thought is it could be that the boat isn't trimmed correctly but I think this is doubtfull.

 

 

Martin

 

[endeavour boats]

the suzuki is approx 70 kgs heavier than the honda. that needs to be taken into account.

 

 

[Adam F]

Onslow,

 

Their is no way that your mate is getting 28 knots with a 50hp engine on a 165 (stand to be corrected now! ) I have run my 165 with both 50 and 60hp EFI 4 stroke engines and downhill, light with the wind behind the best Ive ever had is 27 knots (thats also with the tabs fitted)

 

Are you sure he doesnt have his GPS set to MPH - the usual explination.

 

I would rekon about 32/34 knost on a flat sea with your set up.

 

Adam

[Member Removed]

We will get out in his boat on Wednesday. Then i can see it for myself.

 

I

[Afishionado]

I wonder what all this "What's my top speed" stuff is all about? IMHO and at the risk of some taking offence it all seems a bit over the top. If one was talking about motor cars then even then one seemingly identical car could easily have an edge of 1 0r 2 miles an hour on another vehicle. Atmospheric air pressure, humidity and another half dozen factors would affect the outcome. But to make the discussion even more fatuous, we are sugesting that we make speed comparisons on water. Not just any water mind but the sea, with all of it's variations of wind, tide, and waves. Is one questioning speed through the water? or speed over the bottom? The two could vary wildly! Do you want sustained speed for a given time? If so what is the given time? Or perhaps a average speed over a given distance and then course reversed to give a total average? All these features would alter the top speed of any tested boat.

 

For goodness sake what does it matter what someones imagined top speed is today! 'Cos tomorrow it could be slower or faster........

 

 

 

Mad Mike

 

PS my car's faster than yours Nananaanaa

 

 

 

 

 

 

[Maverick Martin]

Mike

 

As I see it you are 100% correct in what you say.... almost.

 

The top speed question can have many meanings. First as you correctly point out is the top speed is only rarely achievable and in my experience definitely not comfortable both for your back or your pocket. However the top speed is also an indication to whether your outfit is set up correctly. If you take this info and put it with max rpm achieved you will be warned of any incorrect set up. If you are incorrectly propped it could (most probably will) cost more in fuel to run than if you had you rig set up with the right size and pitch of prop. Also the engine will not be achieving its full hp at the prop if you can

[Swainiac]

Mark and I took Nipper out for her first spin yesterday, and she appeared to be revving slightly high. We discussd this during our short sortie, and thought it may be the prop. She handled well, seas were slight, we managed around 25 knts, but seemed to be over revving. Something we need to look at

 

Rich

[Paul J]

The prob is 13,5X15 and rpm is 5900-6000

 

Try a 17 pitch

 

PJ

[Seamouse]

However the top speed is also an indication to whether your outfit is set up correctly.

Have to agree with Martin, whilst it is neither sensible nor comfortable to run max rpm you need to know whether the set-up is correct. I'd say Onslow's isn't, my old 165 would pull 28 knots from a 60hp Bigfoot. Try a bigger pitch prop?

The Pro Angler is a different matter. Evinrude have changed their prop design and the new 17 pitch one is pants, plus I might, or might not, have been given 80lb trim tabs. I'm getting 28 knots from a 75hp but since it is only managing 4200rpm, with a recommended WOT of 4500-5500rpm, I'd guess it is probably only delivering around 60hp. I'm told Warrior have tested a 19 pitch(!) alternative which gives 4500rpm on a brand new e-tec, so should go better after the oiling period finishes.

Added to the prop woes, SeaMouse handles oddly. I've got the trim tabs set on minimum angle and power and she planes easily at almost no speed. Whether she needs them at all is questionable, since even trimming right out can barely get the bows to lift. What's really bugging me though is the handling. On a flat day she runs true and level, in a head sea she's great but a sea on the port quarter is hell. The bows drop off each crest as we cross it so she needs constant course correction and the whole boat constantly lists to port, even moving the crew to stand behind the skipper doesn't completely over-ride it. Any thoughts, anyone? All I can think of is that the starboard trim tab is jamming somehow.

 

Meanwhile, I've got access to a 15 pitch prop, plus a 17 pitch of the old design, so that aspect can be sorted as soon as I get a flat enough day to play around. I've tied the trim tabs out of the way for now and I'll see what difference that makes. Just wish I lived on the coast instead of 2 hours away!!

 

Steve

[Member Removed]

We tried this morning to weigh the boat. (i can do that at work). Boat (550 kg) with 2 chairs and 2 piedestals (50kg ?), trailer (360 kg), Suzuki (162 kg). All in all that would be around 1122 kg.

 

It did in fact weigh 1343 kg !!!!!

 

 

I think the boat is much heavier than the estimated 550 kg, and that might be reason why it not goes as fast as i had hoped !.

 

 

Onslow

 

 

 

[great white]

The general info is as usual varied and mostly correct

 

I do not know what the specs are for warrior boats , but whatever they are they are only guidelines.

 

If both boats were identical in fit out and layout you may do a comparison, but with different size and weight of engines crews fittings etc its a hard one.

 

As Martin states the top speed engine RPM is the best indication

 

The boat should be set up as it would be if used

ie fully crewed and fueled with as much as you usually carry and all kit on or suitably compensated for, tackle weights flasks spare clothes etc

 

then two high speed runs in opposite directions and note the average top RPM from the 2 trips.

 

Changes of About 200 RPM is achieved from 1" of pitch adjustment, and the total pitch adjustment depends on the type of prop.

 

If you are over propped [RPM lower than stated in the book] you will be straining at all loads and in the long term could damage the engine.

 

Better to be slightly the other way

 

If you carry extra crew occasionally at least the engine will not be straining.

 

It reads like your WOT reading is well low which looks as if the prop needs changing. the amount you are out is beyond a simple re pitch.

 

I would check what other warriors are using or with warrior.

 

out of interest how do the fuel consumption figures compare, ie how much more fuel are you burning for the extra 1.5 knots. [ a lot I expect] I would think that the cost of new prop would soon be recovered from running costs with the correct prop.

 

 

I hope that helps

Charlie [ an ex Outboard maintainer [suzuki]]

 

 

[Swainiac]

I just hope they are pedestals efferred to, and not piedastools!!

 

Rich

[Coddy]

Just to add my 2 pennies worth

 

I have a plotter and an old GPS but I never get identical speeds on both instruments. They are normally within 0.5 kts of each other but checking between two boats using differant equipment could make some differances.

 

Just a thought.

 

Coddy

[Seamouse]

It reads like your WOT reading is well low which looks as if the prop needs changing. the amount you are out is beyond a simple re pitch.

 

I would check what other warriors are using or with warrior.

 

out of interest how do the fuel consumption figures compare, ie how much more fuel are you burning for the extra 1.5 knots. [ a lot I expect] I would think that the cost of new prop would soon be recovered from running costs with the correct prop.

Hi Charlie,

I seem to have hijacked Onslow's thread here. Aplogies mate

 

WOT reading is indeed way too low, previous runs only gave 4000rpm and 26 knots!! The tale from Warrior is that the new Evinrude 17 pitch prop design is just too inefficient. The alternative they've sourced ought, at 19 pitch, to give even less rpm but a better profile allows it to get 4500rpm (I'm told). That's probably the prop I'll end up with, but there are other options available for me to play with without buying them first and that's what I want to look at.

 

Fuel consumption is also an issue. The e-tec is 'supposed' to give me 6mpg but with this prop I'm getting nearer 4mpg, comparable with my old 60hp Bigfoot. As you say, changing to a better matched prop ought to pay dividends there.

 

Steve

[Maverick Martin]

I had problems with my engine/prop when I first got it, it would only achieve 4500 rpm. Kept onto Warrior who just said that's the prop we recommend for the best all round performance and fuel economy, balderdash! I went and seen Tom at prop revolutions who did the calcs and said you don't want one of those you wants one of these.... maybe Well turns out Toms guestimate was spot on my Optimax now revs at 5400/5500 depending on the day.

 

What I'm trying to say is talk to the professionals. They do the calcs for free, then for a little investment you could end up saving a small fortune long term.

 

Kept the original prop as a spare. Tried it about 2 years after changing to the new prop and Maverick seemed like a slug getting onto the plane, soon changed back again

 

Martin

 

[great white]

I agree with Martin [As usual mr chairman sir]

 

 

It sounds like some one is blowing bubbles up your butt mate.

 

 

The WOT in the handbook should be achievable by changing the prop size and diameter to the correct one for your boat and engine.

 

Some engines in this size range have an option of about 11 differant props, when considering all the diameters and pitches and a couple of specials for racing.

 

This is to allow the same engine to be fitted to a small light speedboat or a larger heavier day boat.

 

I would talk to the people with a simular set up and the engine people.

 

 

If you are down on revs a bigger pitch will not work unless the diameter is smaller.

 

reading that revs are low and fuel consumpton high. I would say definatly that you need to change the prop. If you have a chance to try a few without purchasing them thats a good option.

 

I once had a Hardy 25 come to Poole from Gosport for servicing and checking of a simular problem.

After a service and new prop which had a much smaller pitch, the boat speed was much higher than ever achieved from new [about 30% better], the RPM was correct and on the way home it used 60% of the diesel it used on the way over.

The ownner was well please with the cost of the prop, he saved a chunk of the cost just on the trip homes fuel .

 

If you are going to the show, its a good place to talk to the various "experts"

 

best of luck

Charlie