SUZUKI DF 115 SPECS. In line or should except better?

[Karnic]

Hi Guys. I have an 18.5 open boat with a SUZUKI DF 115 installed. Propeller size is 3x14x19. Was a bit curious about the correct height of how was OB installed. Could someone guide me in this issue please. Attached please find a YT link which shows how Outboard performs in water. Is outboard sitting low or is it ok? Honestly im finding no issues in handling OB as it is at the mo but your feedback is greatly appreciated. WOT At 5700/5900 RPM im getting 35/37 Knots. Pros and cons. Am i in Line? Installation Bolts are sealed.

[artdf175]

there is a sticky on the main page about the right height you should read
Art

[Moonlighter]

Looks like it could come up a bit to me.

But I dont know how far trimmed out your engine was, nor what make of prop it is, nor what its grip is like in turns and in a following sea because you didnt say anything about those relevant things. They all make a difference.

But anyway as Art recommended, please read the sticky thread towards the top of this forum about setting engine height and selecting props. It gives you all the info you need, and saves us having to repeat it all again here.

And always remember, a good stainless steel prop is going to be able to run higher and will grip better in turns than an alloy prop. You didnt mention your prop material, but from the size its possibly ally?

On my DF115 I run a Suzuki 3 x 14 x 20 stainless prop on my 5.5m cuddy cab boat, and its perfect. This is a very popular size and model prop for the DF115/140 series engines, seems to suit many boat/motor combo’s in that range.

I can pull around 6200rpm at WOT trimmed out to optimum, average load on board, which is spot on for best performance all round.

[Karnic]

Moonlighter , yes prop is ally. I do not have many experience with outboards. Will change prop to Stainless. The thing is that a local has the same boat with the same OB and its further up regarding height. Suzuki Tech confirmed that it is fine. In video trim was half up the gauge not fully trimmed up.

[Moonlighter]

Ok well, still read the sticky thread.

I explain there in detail how to test to see if motor is at optimal height. Here is a link to make finding it easy.

http://www.suzukioutboardforum.com/f...the-right-prop

[Karnic]

Hi Moonlighter. Thanks a lot for your help. Appreciate. As you are aware i do not have experience and your information and expertise for me is valuable. In Fact i really found the sticky thread of incredible help and understanding. Your thread should be issued with the Manuals cause honestly i searched and searched through the manuals and found nothing on optimum height. If possible after reading all the thread with great attention i have some doubts ( questions ) and would really appreciate if you could guide me.
QUESTION 1 Rule 2. Your Suzuki 4 stroke needs to hit its max recommended rpm or close to that to perform its best and have a long, happy life! Does this statement corresponds while on WOT? Because while cruising and boat is in plane( My average cruising speed is 20/25 Knots at 4000/4300 rpms) and boat is in plane, due to waves and rough weather, i am not reaching the 5000-6000 range. Will reach the range when sea is calm and as stated will get 5700/5900 rpms with 30- 37 knots range which i think are quiet satisfactory by my humble opinion. As your statement states IT IS CAPABLE OF REACHING THE DESIRED RPM RANGE but only when on WOT and with favorable weather conditions.
QUESTION 2 a "hole shot" test where we time how long it takes to hit 5000rpm when we hit the throttle hard from idle speed. Use the stopwatch on your mobile phone!. What is the approximately desired time to reach 5000 rpms from idle? Should i open the throttle full from idle and record the time? When testing i will test my DF115 on a 18.5 ft boat loaded with fuel and water and gear and with 2 persons on board.
QUESTION 3 We also record the minimum speed and rpm that the prop will hold the boat on the plane at. This is important for rough offshore weather where you can't go fast but want to keep the boat on the plane. During rough weather i cruise at approximately 20 / 25 knots with 3700 / 4000 rpms. Am i inline? If not what rpm and knot range are optimal to run OB for you during rough weather?

My questions may seem a bit odd for you or sound silly and i apologize for this but honestly i think you can help me in answering my doubts cause your info i found by reading the sticky threads was very useful and interesting.

I would like to Thank you in advance for taking some of your precious time to answer my questions . Appreciate.

God Bless Mate.

[Harper]

Looks like it could come up at least one hole, IMO.

[Karnic]

Hi Moonlighter. Thanks a lot for your help. Found the sticky thread of utmost importance and very interesting. Your exact description and info Should be found also in the manuals cause honestly searched through my manual and found nothing about the correct height. Thanks Again. If possible and if i may ask i have some doubts / or questions and would like you to help me understand exactly. As you are aware i am new to Suzuki outboards and my questions would seem odd or silly for you but would appreciate lots if you can help.
Question 1: Rule #2: Your Suzuki 4 stroke needs to hit its max recommended rpm or close to that to perform its best and have a long, happy life! Is this meant for when OB is operated on WOT? My issue is that Ok while on WOT i reach 5500/5900 Knots approx with 32/35 knots, so i am capable of reaching the ideal revs but ONLY when sea conditions permits. Usually on choppy/rough seas average cruise speed is 20 /25 knots reaching approx 4000/4400 rpms. Usually i cruise on 25 knots. Am i inline? Would like to rule out that im lugging the engine and putting too much load in bearings and rods and using too much fuel.
Question 2 : Regarding the hole shot test because i would like to try it and find if specs are satisfactory. Should i open full throttle from idle all of a sudden till reaching 5000 RPM? If so what is the timeframe to reach the 5000 rpm mark in order to determine if my set up is satisfactory?
Question 3: Would upgrade to SS prop when i will have the money. Should i go for the same size as my existent ally prop or should i look for other considerations?
Question 4 : At the moment im using a cable steering. What are your recommendations / views in upgrading to a Hydraulic steering? Is it worth it? Safety , Peace of mind and less maintenance are priorities.
FYI Boat is an open type 18.5 ft. Mainly used for fishing and recreational.Salt Water ( Mediterranean sea)
Would like to thank you for taking some of your precious time in helping me understand my engine better. Your help regarding these matters are valuable for me and Appreciate lots your kind help and expertise in this matter.

God Bless mate

[Moonlighter]

Question 1 : the tests need to be done in smooth straight conditions that allow 100% throttle. WOT = wide open throttle. Going as fast as it is possible!! Engine trimmed out at WOT until the prop loses grip, then trim in a bit until it grips again. Then record the rpm and speed achieved.

From what you have said, if you can get to 5900rpm, you are not far off the money, and lifting the engine one hole to start with should gain you some revs and get you closer to optimum. And since you can currently get 5900 you can relax, you will not be lugging the engine! So any changes made from here are simply designed to optimise performance, and get the best possible results. The aim is to get from “OK” to “great!”

Question 2. Accelerate hard, yes give it a strong push all the way as far as it will go. Hang on!! Start with the engine trimmed in so the bow doesnt point to the sky, and as you accelerate, steadily trim out. When doing all these tests you need a reliable crew member with you to record the results and work the stop watch.

Its impossible to tell you a target for hole shot because we dont know your boat. The whole idea here is to allow comparisons when you make changes - eg you do the tests and record the results on a sheet pf paper with the motor as it is currently set up, this gives you a base line to compare future changes to.

Then you change ONE THING eg you could lift engine height by 1 hole, then run all tests again and compare results and see if things have improved or got worse. Some things may get better such as straight line speed, but others may get worse such as how easily the prop loses grip in turns. At the end of the day you need to balance these things to reach a conclusion - it is always a bit of compromise.

Question 3: Stainless props are much more expensive, but they do work much better because they flex less, they grip the water better because they are more cupped, and they usually have better shaped blades. One of the most important reasons for doing the tests described in the sticky is so you can show the results to an expert prop shop, they can look at the results and recommend the most suitable prop for your boat/engine combo. A Suzuki alloy prop of a certain size will have different blade shape and cup even compared to a Suzuki stainless prop with the same measurements of diameter and pitch. And if you change brands, the choices become even more complicated. So that is why when you talk to a expert at the prop shop and show them the data from your tests, and tell them things like your boat details and how you use it, they use their extensive knowledge to recommend a good prop. You also give them guidance by telling them what characteristics are important to you. For example, some props lift the stern of boats more and help it plane better at lower speeds. This is often important to offshore fishers so that their boat can plane easier in rough conditions at lower revs for long distances. So they tell the prop guy that and he can recommend a prop with those characteristics.

If you deal with a good local prop shop or even your Suzuki dealer, they may even offer a deal where if you buy a prop from them, you can test it and if its not working right, to exchange it for another one and keep doing that until you get one you are satisfied with.

Question 4: There is no doubt in my mind that hydraulic steering is far superior to cable steering. Its easier to use, doesnt transfer prop torque to the steering so its lighter. But again, like stainless props, its more expensive to buy. A well set up non-feedback cable steering setup can serve you well for many years too. So ultimately its a personal choice, but for me, I would never order a new boat without hydraulic steering!! My last boat came with cable steering and after 5 years the cable started to get bound ip, and I fitted hydraulic steering myself. Once I had it, I swore I would never have cable again LOL!

[Karnic]

Thanks a lot Moonlighter for your kind help and helping me in understanding my engine better.. Will post results of the hole shot test when done. Appreciate.