More Prop advice please Suzuki DF140

[Hightower]

Originally Posted by JohnnyMW

I was thinking I should try raising one hole to see what happens thanks for the advice. I've noticed with the Vipermax that the rear end of the tubes sit quite low on the water, pretty much up to the rubbing strake even when moving at 20knts. Is this unusual or is this another indication that the engine is too low?

I'm assuming that you have a 5.8m vipermax? I have the 6.2m one. Both come from the same mould and rear of the tubes do drag in the water at speed. That's why it has great stability and is a sure footed ride. The 6.5m and above have raised tubes and they sit out of the water even at rest.

[jeffstevens763@g]

looks like you got sorted johnny 6 knot gain bang on.

regards jeff

[Newto]

Originally Posted by Pikey Dave

If it was setup by a decent dealer, then all should be well, I'd assumed it was a self install. Has it been serviced since new? if not, it's due & all the checks will be done as part of the service. If you post up the engine report I can have a look. Look on the report for "TPS Calibration" the number should be 190 +/- 30 so between 160-210

The TPS is showing 186 Dave, this seems ok then? Is it down to prop testing now?

[Pikey Dave]

Originally Posted by Newto

The TPS is showing 186 Dave, this seems ok then? Is it down to prop testing now?
Attachment 101890

TPS good, you're showing 5380 max rpm which is about right, but this might have been when the boat was airborne at some point. Are you positive that you had the throttle wide open when you only managed 4600?

[Newto]

Didn't really push the lever that hard, I will have a look and also take it on another run next week. I'll test a few things and hopefully get it right by spring. I'll let you know the outcome of my findings.
Thank you again for advice Dave!

Happy New Year!

[Newto]

Originally Posted by Pikey Dave

TPS good, you're showing 5380 max rpm which is about right, but this might have been when the boat was airborne at some point. Are you positive that you had the throttle wide open when you only managed 4600?

Tested this weekend with a new 15" prop, with three onboard and full tank got to 5100rpm running at 38mph so quite pleased with that! Thanks for your advice Dave, just need some warmer weather now!
😃😃

[freespirit3]

Originally Posted by jeffstevens763@g

jonny

i have a 90 Suzuki on a 6m rib-quest with a 14 x 19 Ali prop i get 39 knots flat water no wind or tide @ 5800 rpm.
with a powertech prop 13.5 x 21 stainless steel roughly the same.
with a 14 x 20 stainless steel it drops the revs around 500 rpm and around 30 knots top end.
two people up 70 lts of fuel 20 kg of kit.
you could speak to Dave rose at rib-quest his brother in law has done quite a bit of prop calcs on a 140 Suzuki on a red-bay 6m.

hope that helps

regards jeff

I think I have finally got the prop I need.

The redbay 6.1 is quite heavy and (and mine is a 2002) a deep V, mine has six seats and I tested with about 90litres of fuel and three adults on board.(admittedly young adults, but lighter than me!)

STD prop that came with the boat
3 x 14 x 21 WOT 5600rpm Max Speed 34 knots
Had it repitched by Castle Marine
3 x 14 x 19 WOT 6000rpm Max Speed 35 knots
tried a Suzuki S/S Solas
3 x 14 x 20 WOT 6050rpm Max Speed 35.4 knots
tried a powertech S/S
3 x 13.5 x 21 WOT 5900rpm Max Speed 32.1 knots

bought a S/S Michigan Ballistic WOW !!
3 X 1/8 X 21 WOT 6000rpm Max Speed 38.3 knots
Much more grip, fine balance, reduced cavitation. lots of cup and looks like bits missing off the blades buts works, great overall

Tried the S/S Michigan Ballistic
3 x 13 3/8 x 19 WOT 6200> if you wanted and 35 knots (no good but could be if you had a heavy boat with dive gear, shot onto the plain.

I would like to thank Corrowyn at Castle Marine for all his patience, advice and sourcing this prop.

I feel I now have the best speed, best grip and should be the best boat speed for engine speed hence improved MPL

Ps I have heard that you have to be careful with these props as they can give too much stern lift and cause other issues such as engine overheating, mine hasn't as it is heavy.

Will have to wait for the next Ty Calch cruise with the BS brigade for more information.

For any of you looking for that special extra, well worth a try.

[freespirit3]

Prop fitted to replace the Suzuki stock prop

[freespirit3]

And another in all its beauty.

Please note this worked for me and as I found props are trial and error and not a straight forward science, I hope this is good advice for any of you with a similar issue.

I agree with many of the members that perhaps one of the issues is that the older DF140 seems to be lazy and does not feel like a 140bhp engine, this one has certainly come alive and feels more responsive.

Compromise is the best solution, mine will never be a 40knot plus boat but now it feels happier and will maintain the great Redbay sea keeping capabilities. Win Win

[mick]

Originally Posted by freespirit3

And another in all its beauty.

Please note this worked for me and as I found props are trial and error and not a straight forward science, I hope this is good advice for any of you with a similar issue.

I agree with many of the members that perhaps one of the issues is that the older DF140 seems to be lazy and does not feel like a 140bhp engine, this one has certainly come alive and feels more responsive.

Compromise is the best solution, mine will never be a 40knot plus boat but now it feels happier and will maintain the great Redbay sea keeping capabilities. Win Win

Aye them Redbays are not the fastest but keep going in poor conditions

[Pikey Dave]

Originally Posted by Newto

Tested this weekend with a new 15" prop, with three onboard and full tank got to 5100rpm running at 38mph so quite pleased with that! Thanks for your advice Dave, just need some warmer weather now!
😃😃

You're still a bit low on max rpm, you should be seeing 5600


.....sh1t happens.......

[RMS]

Like you say it looks a little unusual, but sounds like you have a good match. Do you mind me asking how much? Curious to see how well it might match my boat (Ribquest 6.3 with 2010 140 Suzuki) Tony T and I have been swapping notes about props recently as he has the same set up as me.

[Pikey Dave]

Originally Posted by freespirit3

Compromise is the best solution, mine will never be a 40knot plus boat but now it feels happier and will maintain the great Redbay sea keeping capabilities. Win Win

Couldn't agree more. I'd happily sacrifice top end for handling any day. Give me a boat that will do 20-25kn in lumpy weather & a head sea, over a 45kn slammer anyday

[tony t]

Originally Posted by RMS

Like you say it looks a little unusual, but sounds like you have a good match. Do you mind me asking how much? Curious to see how well it might match my boat (Ribquest 6.3 with 2010 140 Suzuki) Tony T and I have been swapping notes about props recently as he has the same set up as me.

We will get to find out on the 27th Richard ... If he overtakes us he could have a battle on his hands


Sent from my iPhone using RIB Net

[Dan Gurney]

Interesting stuff. Think I'm going to let the engine bed in a bit (still only just over 20 hours on) before messing with the prop. We had 37knots on the GPS with 150 litres on board in Ireland but I don't think RBs are set up for speed: mine has a noticeable offset and is set quite low resulting in a bit of splashing round the transom.

As has been said before if I'd been concerned about top speed I probably wouldn't have bought a Redbay. Not ruling out playing with props later on though.

[Callum Stewart]

I think the problem is the Suz 140hp is not a true 140hp. When we had our 6.1mtr with a 150hp Jonnyrude and a 19" ballistic prop we would get 45kn+

My brothers RB 6.5mtr with a Suz 150 is good for 40kn with all the MCA code gear on board & the hull is a very heavy layup.

[Pikey Dave]

Originally Posted by Dan Gurney

Interesting stuff. Think I'm going to let the engine bed in a bit (still only just over 20 hours on) before messing with the prop. We had 37knots on the GPS with 150 litres on board in Ireland but I don't think RBs are set up for speed: mine has a noticeable offset and is set quite low resulting in a bit of splashing round the transom.

As has been said before if I'd been concerned about top speed I probably wouldn't have bought a Redbay. Not ruling out playing with props later on though.

Dan, I'm in a similar situation to yourself, i.e. shaking down a new boat with a DF140. I have lifted my engine 2 holes from where it was set by Ribcraft. I had a lot of splashing around the transom, landing heavily on the port side after being airborne porpoising at high trim etc. Also the prop would cavitate badly to the point that the rev limiter kicked in, this was when landing after "catching air".
We took the boat to Whitby on Sunday after raising the engine & putting 25kg of sand in the bow. The weather was interesting, we headed north into a 2m head sea & the difference in handling was marked. The port list has gone, she lands straight & with no cavitation on landing, the prop bites straight away (I can't explain why lifting the engine would reduce cavitation, but that's props for you). It was too rough to try WOT, but I got her upto 5500.
I have the 21" ally prop on at the mo, which I think is about right. I got a SS as part of the deal, but we are waiting to decide which one to go for until we determine the ideal pitch.
Personally I prefer to run slightly underpropped as it gives better response in the rough for the sake of a few Kn at the top end. I'm a big fan of 4 blade props for the increased grip that you get, but I've not looked into them yet to fit the Suzuki. Unfortunately the Mercury Rev4 doesn't fit

[freespirit3]

I was I guess just underwhelmed with the engine performance, I could not trim out more than half before the prop cavitated and this was with the mix of props I tried.

My engine was also low set when I bought it, I have moved the engine up one hole (mainly because of the jet ski style spray coming up from the transom! the engine is still a touch lower than the keel so grip is not compromised but spray is dramatically reduced.

If you do turn fast now with some trim and you get some cavitation then you just trim in and the prop recovers very quickly, previous prop would need speed to be reduced and trim in before you get the grip back.

The handling has always been great with a soft neutral
ride but I put that down to the hull design, layout with the console well up front and the large 150 litre tank under deck. (And the heavy skipper) this is hence why the boat will never be the fastest, again we did not buy the RB for this.

Now the engine will trim out way past half way without losing grip, gaining some extra speed, but more importantly it feels to me as if it is normal now as it should have been before if this makes sense. Would have been interesting to try the prop with engine in it's lower position, but it's all siko flexed in now.

I also understand that the newer RB 6.1's are lighter now so not so much oomph is needed.

[freespirit3]

Originally Posted by Dan Gurney

Interesting stuff. Think I'm going to let the engine bed in a bit (still only just over 20 hours on) before messing with the prop. We had 37knots on the GPS with 150 litres on board in Ireland but I don't think RBs are set up for speed: mine has a noticeable offset and is set quite low resulting in a bit of splashing round the transom.

As has been said before if I'd been concerned about top speed I probably wouldn't have bought a Redbay. Not ruling out playing with props later on though.

Very jealous of your new boat, do you have any pictures, layout, colours etc, I also understand that the newer df140 engines have a very different final drive and being lighter should perform better.

Sounds like yours is pretty close to perfect, with that much fuel 37knots is great.

[freespirit3]

Originally Posted by RMS

Like you say it looks a little unusual, but sounds like you have a good match. Do you mind me asking how much? Curious to see how well it might match my boat (Ribquest 6.3 with 2010 140 Suzuki) Tony T and I have been swapping notes about props recently as he has the same set up as me.

Will send you both a pm, will bring the prop with me,