Reply
 
Thread Tools Search this Thread
 
Old 25 April 2016, 13:12   #1
Member
 
Country: UK - Wales
Town: Newport
Make: Ribeye TS370
Length: 3m +
Engine: Suzuki DF20AES
Join Date: Apr 2016
Posts: 47
Suzuki DF20AES - prop size

Hi Guys (& Gals?),

Been a reader of the forum for some years and got some good ideas from it. I've had 2 hard boats - a 19' with a 175 Merc and a 16' with a 75 Mariner, a few SIBS with a 4 Mariner but now own a Racing Dinghy (RS400 for those in the know) and more recently a Ribeye TS 370 with a Suzuki DF20AES on it. This latest edition has led to my joining and wanting to post.
I used to run the Mariner 9.9 on the RIB but it was underpowered for the load we often carried and it struggled to plane. I decided upon the DF20 upgrade as it was the largest motor allowed on the transom, and it was lightest in it's class (or it was until I decided to add the Electric start). Very happy with the rig until recently as we got to the end of the running in period. With just two in the boat it over revs as the second crew slides back in the boat. With just one aboard it is constant. Tried trimming it in one but still the same. This is particularly annoying as I had informed the supplying dealer what boat it was going on with a view to prop selection and he advised I stick with the standard 9 1/4" x 10".
On a US forum for "Tinboats" I have since read lots of comments about the DF20 over revving with the stock prop. Looks to me like I ought to have gone 11" or maybe even 12" - the largest Suzuki make for it. It's a costly experiment, so I'm hoping someone on Ribnet may have had some
experience with this motor or similar size outfit and could advise. The hull is Alunimium and the whole rig is really light until I get in! The manufacturer keeps referring me to the supplying dealer and he is ignoring me despite having told Suzuki that they acknowledge receipt of my query and will get back to me. Eight weeks later - nothing.

Sorry for the long post, hope to get some words of wisdom back.

Thanks

Dave
__________________

__________________
seadogdave is offline   Reply With Quote
Old 25 April 2016, 13:56   #2
RIBnet admin team
 
willk's Avatar
 
Country: Ireland
Make: Redbay Boats
Length: 9m +
Engine: 370hp
Join Date: Feb 2008
Posts: 12,924
RIBase
Welcome to RIBnet (at last )

You'll have read this I'm sure?
Suzuki DF20AS EFI - Impressions and review.

Sounds like you got a really fine pitch "as standard"
__________________

__________________
"Who knows what evil lurks in the hearts of men?"
.
willk is offline   Reply With Quote
Old 25 April 2016, 14:39   #3
Member
 
Country: UK - Wales
Town: Newport
Make: Ribeye TS370
Length: 3m +
Engine: Suzuki DF20AES
Join Date: Apr 2016
Posts: 47
Wow that was a quick reply. Must admit I hadn't seen that post. It is pretty recent and started after I began my quest to get help from the dealer.
As chance would have it, immediately after posting my message I checked my email the dealer had finally replied. Unbelievable coincidence. He has recommended a 12" on the basis that with 1 on board it is always over revving and offered me a 10% discount on same.. Having read Fenlanders findings however I am wondering if that may be a step too far?

Timing is everything and had I known before Fenlander bought his 10" I'd have swapped mine for his 12 and tried that. Got a feeling that I'm going to end up with an 11" though.

I don't really understand why two new engines can be shipped with different sized props off the shelf. I wish I'd had his.

Thanks for the link.

Decisions decisions! I'll wait a while and see what if anything others say and let you all know the outcome.

Thank

Dave
__________________
seadogdave is offline   Reply With Quote
Old 25 April 2016, 15:13   #4
RIBnet admin team
 
willk's Avatar
 
Country: Ireland
Make: Redbay Boats
Length: 9m +
Engine: 370hp
Join Date: Feb 2008
Posts: 12,924
RIBase
Hi Dave

Yeah - we aim to please

Your situation is not entirely the same as Fenlander's - he has a soft bottom and that can slow a man down something terrible. What I mean is that if you use the same prop as him, you might get an extra few revs out of it. He'll be along shortly to keep you right!
__________________
"Who knows what evil lurks in the hearts of men?"
.
willk is offline   Reply With Quote
Old 25 April 2016, 16:33   #5
Member
 
Country: UK - England
Town: East Anglia
Boat name: Nimrod II
Make: Aerotec 380
Length: 3m +
Engine: Suzuki DF20 EFI
Join Date: Nov 2007
Posts: 3,275
Hi Seadogdave... another David here.. welcome to the forum.

My initial judgement on pitch was largely based on the excellent Russian Youtubes of a DF15 fitted with the different pitch props and revs/speeds recorded (see post #24 of the thread linked below).

Mine isn't run in yet so it wasn't appropriate to do speed trials but I will give my own comparison between 10" and 11" as soon as I can.

However I'm sure you would need at least an 11" if not a 12" with a light load and such an efficient hull profile. There's a guy on here who also has an Aerotec plus a Suzuki DF20 he's owned for about 3yrs. He also briefly had an Frib which has a similarly efficient hull as yours and he suffered over revving on a 10" prop with that or when lightly loaded using the Aerotec.

See his post #21 on this thread where I was asking for opinions on the Suzuki before ordering... Suzuki DF20AS 4-stroke new - Any opinions?

For our part the V hull of our SIB plus the fact we are usually two sturdy adults + teen + dog + lots of fuel + too much kit means a standard 10" is more likely to be our ideal prop.

Where are you based and where do you launch? How do you like the Ribeye?

Oh and just to be sure when you say... <<< With just two in the boat it over revs as the second crew slides back in the boat. With just one aboard it is constant.>>> do you mean it hits the rev limiter? It's not prop slip/ventilation is it?
__________________
Fenlander is offline   Reply With Quote
Old 26 April 2016, 03:26   #6
Member
 
Country: UK - Wales
Town: Newport
Make: Ribeye TS370
Length: 3m +
Engine: Suzuki DF20AES
Join Date: Apr 2016
Posts: 47
Hi Fenlander. WillK wasn't joking when he said you'd be along soon was he! Cant fault this response time.

OK so clarity first. I think with the crew sliding forward that little extra weight up front buries the bow a touch and it slows the boat just enough to prevent over revving. If it was ventilating I don't think this would make much difference. I did try trimming it in a bit to be sure but made little difference save for how far back my crew moved before it starts over revving. It is actually uncanny how specific the point is. They reach a certain point on the tube and bang on - first misfire from the over rev protection.

I am erring toward the 12" but there will be occasions when there'll be 4 in it and as much as I don't mind it taking a bit longer to start planing I do want it to be able to achieve it so I'm wondering if 11" is the way to go? Do you still have your original 12"? How would you feel about swapping your 12 for my 10? If it's too high I then only need to buy one more prop - the 11" and I could keep your 12 as an emergency one plus you get a spare of your ideal size. Don't feel obliged. Just a suggestion. Mine is still unmarked. You're a bit far away for a road trip to just experiment.

As for usage, I mentioned that I am a sailor and as much as I sail mostly on inland waters we do like to take the boat to the Seaside occasionally. When we do we try to bring the RIB for safety cover. It has come in handy more than once after the wind abandoned us. Outside of sailing we also use it for exploring the coastline a bit. Find a secluded beach and swim etc etc. Just love being on the water. We used to Scuba dive in our younger years but I now keep a marine reef aquarium instead. In hindsight I'm not sure which was less effort :-)
__________________
seadogdave is offline   Reply With Quote
Old 26 April 2016, 03:51   #7
Member
 
Country: UK - England
Town: East Anglia
Boat name: Nimrod II
Make: Aerotec 380
Length: 3m +
Engine: Suzuki DF20 EFI
Join Date: Nov 2007
Posts: 3,275
>>>we also use it for exploring the coastline a bit. Find a secluded beach and swim etc etc. Just love being on the water.


Yep that's our use too.

Pretty well every other Suzuki DF20 I've heard of has come with a 10" so it was odd that my dealer told me I had to wait until the outboard arrived before knowing which pitch it would have... but I did notice this in some small print when looking at a Suzuki brochure. Like your dealer my guy's understanding of pitch requirement on a SIB/RIB was lacking and I had to push him to agree if I wasn't happy with the supplied prop he'd swap it out FOC. During the order process he found mine was already fitted with a 12" and pressured me to accept an 11" rather than the 10" I'd have ideally preferred. I accepted the situation though as I thought it would add flexibility if I bought a 10" as well because we always carry a spare on holiday.

So the dealer took off the 12" and replaced it with the 11" he'd ordered in. He muttered something about either returning the 12" through Suzuki or selling it at a discount. As he's located on an inland river I don't think he'll have much call for a 12" on a 20hp. So he could just have it left in stock and be willing to deal.

However I doubt he'd sell it cheaper than you could buy a 12" Solas anyway (£76) as the OE Suzuki 12" ones are around £117...

Propeller Shop :: Suzuki :: Suzuki DF15A / DF20A 2012 -Newer :: ALUMINIUM PROPELLER 3 BLADE 9.25 x 12

Do you have a GPS to know the speeds when this over-rev is happening?
__________________
Fenlander is offline   Reply With Quote
Old 26 April 2016, 04:28   #8
RIBnet supporter
 
Chris Caton's Avatar
 
Country: UK - England
Town: Wirral & Caernarfon
Boat name: That's Enuff
Make: Revenger & Avon SR4
Length: 7m +
Engine: Honda 150HP & 50HP
Join Date: Jul 2011
Posts: 4,199
give castle marine in Caernarfon a call, they had a pallet of 2nd hand props which they could rebuild, worked out around half the price of a new prop, they done a couple for me now and I've been very pleased with the results, they also do stainless prop repairs with excellent service too, nowt to lose for a phone call

Home Page
__________________
Member of S.A.B.S. (Wirral Division)
Chris Caton is offline   Reply With Quote
Old 26 April 2016, 07:44   #9
Member
 
Country: UK - Wales
Town: Newport
Make: Ribeye TS370
Length: 3m +
Engine: Suzuki DF20AES
Join Date: Apr 2016
Posts: 47
Fenlander: she's cutting out at about 22.5 kts. Plenty fast enough for this little boat on flat water, but I don't want to rely upon other's mechanical sympathy not to leave it bouncing on the limiter. I'd rather the load do that. Think I'm erring toward an 11" despite the dealer advice of 12. I think he's just guessing like the rest of us but it's at my expense.

Chris: when I first got into this I did call Castle and they quoted £50 to repitch my existing. The DF15 and 20 use a 10 spline hub unlike the older strokers which used 11 spline. As a result old damaged props in this diameter are harder to come by and I tried several repairers. Given that I need a spare it made no sense to re pitch so Best Buy another and keep the 10 as an emergency spare.
Brings up on other question though. If I saved a £few and put a solas 11 on it, can I be sure it will give me the same step change as an 11" oem prop would?. Though both 11", one may have more or less cup than the other for example and it may muddy the waters if I don't stick with genuine Suzuki to make the comparison. Just adds another variable.

What I really need is someone closer willing to do a swap/ trial.

Cheers for the replies.

Dave
__________________
seadogdave is offline   Reply With Quote
Old 26 April 2016, 09:17   #10
RIBnet supporter
 
Chris Caton's Avatar
 
Country: UK - England
Town: Wirral & Caernarfon
Boat name: That's Enuff
Make: Revenger & Avon SR4
Length: 7m +
Engine: Honda 150HP & 50HP
Join Date: Jul 2011
Posts: 4,199
sounds like the waters are already well and truly muddy, good luck with the search, guess you need to find someone with some spare props knocking around
__________________
Member of S.A.B.S. (Wirral Division)
Chris Caton is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 09:13.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.