Re-propping a Suzuki DF140

roycruse · 04 September 2005, 03:10

I don't have my boat yet but have been trawling the net looking at the various 3rd party prop manufacturers and trying to decide where to buy my first replacement / spare propeller.

It seems that the Suzuki DF140 engine has a low gear ratio for the size of engine of 2.38:1 which Suzuki claim means that it can turn a larger diameter prop.

The only problem is that all the third party manufacturers don't seem to have allowed for this and all the props available are of around the 13" diameter.

After finding a very interesting article on the piranha site http://www.piranhapropellers.com/bulletins/Suz4Stk.pdf stating that using a 13" prop will have no where near enough blade surface area when compared to the Suzuki original for the DF140 causing excess slip and cavitation and suggesting that you use their 4 blade hub with blades intended for their larger gear case model hubs. This all sounding like a very reasonable and logical argument.

This in my mind would leave only 2 choices :-
(1.) Only buy the 14" original Suzuki propellers
(2.) Get a piranha 4 blade as described in their article.

Suzuki original props are likely to be very expensive and harder to come by second hand and Piranha props seem to be very scarce in this country (and I'm not sure I like the idea of composite anyway)

So my question is what experience have all you other Suzuki DF140 owners had when re-propping your boats and how did the props you chose perform?

Richard B · 04 September 2005, 09:34

Question is, what do you want from your spare prop?

Do you want the same size, but just a "cheap-get-you-home" prop in case of bushing failure?

Do you want a different size for performance testing?

I would wait until you know whether your 1st prop is the correct size or not, see if your boat will reach maximum revs at WOT, or if it's reaching max revs too early. Then you'll know if you're looking for a different size prop or a spare the same size.

OEM props are, IMHO, the way to go. Unfortunately they are expensive. Some aftermarket props are slightly cheaper, but I don't rate them for use as a main prop. I have a Pirhana composite as a spare, but have never used it so I can't comment on their performance.

roycruse · 04 September 2005, 11:01

Yes - this was my plan - once the engine is run in I was goping to replace the standard prop (I think it will be a suzuki 14 X 21 ally) with a stainless either 20 or 22 (if I i was buying Suzuki original) depending on as you say whether I feel I need to go up or down a pitch. This would then leave me my original ally prop as the spare.

I was just researching the possibility of third party props but seemed to be finding that there wasnt much choice when it came to this suzuki df140 engine.

Is anybody actually using a non suzuki prop on thier df140 - if so what is it and how do you find it?

Richard B · 04 September 2005, 12:53

I think Alex Brown has a Solas s/s prop on his, IIRC.

I'm not the number one fan of Solas props though!

Alex Brown · 04 September 2005, 21:11

Yeap, as Richard says, I have a Solas prop on my DF140.

If I remember right, it's 13/7/8" diameter, 21" pitch high rake.... The actual diameter looks pretty much the same as the suzuki original ali prop. I went for this prop cos apparently the high rake makes the prop nearer 22" or something - not sure exactly how it works.

The reason why I wanted stainless is cos the ali prop was starting to get tiny chips in it from river use - I've no idea how cos it never touches the ground (haven't yet anyway touch wood). Replacing the ali suzuki prop (genuine part now) works out about the same price as the stainless Titan prop so I figured I could go along with that.

If you like playing around and cornering hard at silly speeds, then the stainless is better than the ali with the water grip I find - also, it bites the water quicker after a brief amount of flight time whereas the ali prop takes maybe a fraction of a second longer.

Speed performance, well, err, the ali prop is about the same as the stainless at wot to be honest. Maybe the stainless gets me an extra half knot or something in perfect conditions, otherwise nothing that you'd notice much.

Richard had problems with his bush, but I hope, and assume that's cos his engine puts out a lot more power than mine - so far, I haven't seen any indication of failure on my prop. Every so often, I'll take the thing off, check it, re-grease and pop back on again to make sure it's all fine.
Locally, I don't bother carrying the spare ali prop with me on the boat, but I think if I went away for a weekend or over to Ireland or something then I maybe would.

If you're literally after a get me home prop, I'd get the cheapest ali prop you can find that will fit the suzuki. If you want something to last a bit longer and not show signs of general wear so much, I'd look at stainless anyway.....

-Alex

roycruse · 09 September 2005, 16:20

Where did all the DF 140 owners go ???

Is there no one else running a DF140 with a non OEM prop that can tell me how it performs ?

Burdick · 09 September 2005, 17:17

I also have a DF140 and need to change the standard prop that it came with. After 190hrs it is not as perfect as it should be and caught the odd sand bank. There are a good 1/2 doz DF140's in the marina where I berth and most seem to have S/S props. Will need to some more homework and also see what else this forum throws up.

Jono Garton · 09 September 2005, 19:59

I wouldn't use a ss prop on a df 140!

I hit a rock at tick over revs and it did not damage the prop much at all, however it did snap the drive shaft at the krank end, ouch!

Id rather smash a prop than a drive shaft, is it worth it?

If anyone wants any df140 aly props i have a selection.

Alex Brown · 10 September 2005, 09:21

Jono,

Can I ask what the approx cost was to fix the broken shaft?

Thanks,

-Alex

Jono Garton · 10 September 2005, 10:13

It was cheaper for a new box than to rebuild the gearbox with new drive shaft. The Power Head had to come off to get the old shaft out.

All in all the bill came to about £3500

roycruse · 10 September 2005, 10:46

Isnt there supposed to be rubber bushings in props to stop this kind of thing happening.

What make stainless prop did you have on that caused yoor drive shaft to break.

Jono Garton · 10 September 2005, 11:23

Quote:

Originally Posted by roycruse

Isnt there supposed to be rubber bushings in props to stop this kind of thing happening.

Yes

Quote:

Originally Posted by roycruse

What make stainless prop did you have on that caused yoor drive shaft to break.

Standard Suzuki Aly Prop

Alex Brown · 10 September 2005, 11:28

Surely though, if you're idling, and the ali-prop hit rock, the impact to the engine would be similar? - I'd expect a nice dink in the ali prop and probably a small mark on a stainless prop, but I wouldn't expect something pretty fundamental inside the engine to go twang

I know of a couple of people locally who have hit pots at full speed with ali props, and it has been the gearbox that ended up being replaced, not the prop or the bush.

Does anyone else have any experience of a drive shaft failure within the DF140 I wonder?..... I'll trawl through some of the US forums later on....

-Alex

Nauti Buoy · 12 September 2005, 12:05

Just off Chichester, on a very very flat sea I mangaged to get 48 knots at 6000rpm. I am using the Standard prop that comes on the Suzuki DF140 on the back of my new Avon 580DL SEASPORT

roycruse · 12 September 2005, 14:44

Quote:

Originally Posted by Nauti Buoy

Just off Chichester, on a very very flat sea I mangaged to get 48 knots at 6000rpm. I am using the Standard prop that comes on the Suzuki DF140 on the back of my new Avon 580DL SEASPORT

You say standard prop - i assume you mean the standard aluminium one - but what pitch - is it 21"

Nauti Buoy · 12 September 2005, 15:50

Quote:

Originally Posted by roycruse

You say standard prop - i assume you mean the standard aluminium one - but what pitch - is it 21"

Yes it is the standard 21" aluminium prop.

roycruse · 12 September 2005, 15:56

48 knots - that good to hear

I think I should be able to get similar top end out of my ribcraft when I get it. - similar sized boat... after ive run it in that is...

Nauti Buoy · 12 September 2005, 16:11

Quote:

Originally Posted by roycruse

48 knots - that good to hear

I think I should be able to get similar top end out of my ribcraft when I get it. - similar sized boat... after ive run it in that is...

Mine took 20hrs but soon had it done, you'll get annoying bleeping sound, plus oil flashing warning light, telling you it's time to get it serviced at 20hrs.

I was very impressed with my new Rib at 48 knotts, ok I know I was on a flat sea but it was absolutley solid, no wobbling, felt very balanced, even turning at that speed felt reassuring. No doubt stick some chop in that and it will be a different story.

Robox · 12 September 2005, 17:50

[I was very impressed with my new Rib at 48 knotts [/QUOTE]
Richard,
I bet you were,i should think you had a smile on your face something like this

at the time.

Rob

Alex Brown · 12 September 2005, 18:10

How come at 6000revs on mine, with 21" ali suzuki prop, I maxed out at only 41knots

You must have an incredibly low amount of slip on that prop to get 48knots at only 6000revs - I'd expect the engine to be nearer 6300revs to get that sort of speed.

I assume you've measured that on gps on slack water?

-Alex