Wet ride from DF140

[Dan-Weller]

New member that needs advise, Here is my set up and problems. I purchased a 2016 Alumacraft 175 Trophy with a 2016 DF140 Suzuki. It came propped with a ss 14x22 prop. The motor is mounted in the second hole from the top. The rig is currently in storage for the winter as I am in a cold weather state. I know I have to check the position of the lower fin just above the prop after reading the sticky but need to wait till next spring. The boat porpoises badly forcing me to trim down the motor, top RPM is about 5400 as I recall, and top speed is 37mph GPS. Even more annoying is the amount of water spray I get coming over the transom and no, its not transducer related. It caused by the motor. The Hole shot is ok with 2 people and 35 gals of fuel but is noticeably lacking with three people. Looking at the specks from Alumacraft the motor is rigged and propped as recommended but should rpm at 6200 with a top mph of 45. The boat steers a little hard also. Anyone have a recommendation?

[Moonlighter]

That's showing all the symptoms of a motor mounted too deep and likely over-propped as well.

Almost a text book case IMO.

Porpoising, throwing a lot of water around from the motor, slow hole shot and failing to reach max rpm. Not much more to add to that list!!

As per the sticky, get the engine height sorted first. Sounds like you can go up 2 holes at least.

You didn't mention the prop manufacturer? Suzuki or something else?

The 3 x 14 x 20 Suzuki stainless seems to be a very effective option on the DF115/140 motors, I run same prop on my DF115, also on an alloy boat but one you won't have heard of in the USA - mine is a Surtees Workmate 550, about 18ft cuddy running 18 Deg V hull. Throw the throttle down and you'd better be hanging on!

Many others I know with those motors run the same prop I'm using.

Even if you pick up a couple hundred rpm with the engine height lifted, likely that you may still find this prop a good option to get your revs where you need to be.

In any case, your objective should be to get at least 6000rpm at wot with an average load.

Goo luck, let us know how you go.

[Dan-Weller]

That's kinda what I guessed. I am in my upper 70's and not sure I can handle raising the motor myself or with my older friends. Not concerned about paying the dealer to raise the motor just want to make sure its right so I don't have to redo or put it back its about $150 each move. It would be nice to find someone with the same setup with the same issue and remedy. The prop is a Suzuki 14x22

[Moonlighter]

Fair call, Dan. Best to be careful.

The big give-always for the motor set way too deep are the porpoising and the excessive water being thrown around from the leg. And to an extent, the heavy steering.

Assuming of course that the porpoising isn't caused by bad weight distribution or a hook in the hull, both unlikely in a new boat. But when the weather allows, checking the cav plate height when underway as described in the sticky will confirm the engine height is either OK or not.

If you know someone with a block and tackle or even a 4WD hand recovery winch, and have somewhere high and strong enough to hook it up to it, lifting the engine is then easy because they have a lifting point on top. You'll see it when the cowl is taken off. Just use the winch to take the weight, undo the bolts, then lift her up, redo the Sika, then put the bolts back and tighten. Then have a beer!

Feel free to send some of that cool weather over to us in the Southern Hemisphere - it's 30C (86F) and over 70% humidity here this morning! And that's after we had a storm earlier this morning that cooled things down quite a bit!

I googled your boat and she sure looks like a great rig! Would be quite similar in weight to my Surtees, although mine probably a little heavier due to 4mm hull/3mm sides and cabin, plus the higher cabin and roof. The one thing I couldn't see on the factory website specs was the deadrise angle?

Should fly with the 140hp Suzuki when you get engine height sorted.

Link to the Surtees factory website and the Workmate 5.5 model same as mine:
http://www.surteesboats.com/our-range/boat/550-Workmate

[Dan-Weller]

Moonlighter, Thanks for the suggestions, it has given me the confidence to move the motor up if need be. I will check the position of the cavitation fin first. We have cold weather moving in today and the lakes/rivers will be iced over soon. It's 21 F this morning. I checked out your boat, it looks to be ideal for your situation. I presume your on a coastal area. Anyway, I will keep you advised on what happens with my boat. May be it will help some one else in the future.

Dan

[JWBoater]

Is there any update Dan?...

I have the same rig but a 2013 model... Same mount point as well. Ive been thinking about raising mine also.

Just wondering if you got it taken care of since the weather has been nice.

Thanks

[Dan-Weller]

jw boater, so sorry for the late reply. I tried to respond but had trouble with the web site. I see you got your situation resolved. I raised my motor one hole as was recommended by Alumacraft which improved the performance but is still lacking so I will go one more hole up soon as I have some help again. To far from the dealer to take it there.

[JWBoater]

No problem on the reply time Dan. I did get mine resolved quite nicely. Raised it to the second hold from bottom... and a nice snappy difference. I have the same hull.. well 2013 model Trophy 175 and a '13 DF140A with the Suzuki SS 14/22 prop. I have been toying with the idea of a fin on the prop or trim tabs on the hull. There is a company that makes trim tabs that are spring driven, not electric... that have a quick release mount that you can tilt them straight down to slow trolling speeds. My only real issue with that is I already have a 9.9 kicker that gets me as slow as I could possibly ever want. My wife tells me to just be happy .. lols

[WEDOCQ]

Did you finally get your problems solved? I agree the motor is probably sitting too low, BUT, I think you are be over-propped as well. When I plugged your numbers into the online prop slip calculator, it said you were getting a slip of 22%. Even if you were achieving the numbers Alumacraft claims it should (6200 rpm and 45 mph) the slip calculates to be 17%. From my understanding, a slip percentage under 10% is ideal. Things that cause slip (and thus not running the most efficient) are: Aluminum props, poorly designed props, motor too low on transom, incorrect prop pitch.

So in theory, if you raise the motor, and lower the prop pitch, the slip will reduce as well. With a lower pitched prop, you will get better hole shot as well.

Good Luck,
Shawn

Prop slip calculator. Your gear ratio is 2.38
Prop Slip Calculator | Mercury Racing

[singr1]

DF140 wet ride

I have a 2013 DF140 on 175 Trophy with a 14 x 20 SS prop. Motor is mounted in 2nd hole from the top. When trimmed down all the way, the cavitation plate is higher at the front than at the back. I believe this is causing major splashing onto the sides of the motor(not caused by transducer) and onto passengers seated in jump seats, even when the boat is up on plane. When I trim it up(hit button twice) the motor still gets splashed at 4000rpm. If I trim up further at 4,000 to 4500 rpm, the boat start porposing. The only way to get rid of splashing is to run wide open at 6,000rpm and trim up and she does not porpoise. Yes trimming up does get rid of the splashing when cavitation plate is level(front to back). This can only be done in calm water and without the rear livewell full and front livewell is full. As soon as more than 2 people are in the boat, the splashing gets worse. To this point I only use the front livewell and pack as much weight in bow as possible to prevent porposing. My goal is to be able to use both livewells with 3 people on board and run at 4,000 to 4,500 rpm with no splashing on the motor and no porposing. I welcome any thoughts on raising the motor 1 or 2 holes and what affect this will have on max RPM and porposing. When planed out at 4,000 rpm where should the cavitation plate be in the water? I don't want to raise motor too high so that prop loses grip on turns. I do tow skiers/tubers in July/Aug and am toying with a 4 blade prop. Thoughts? Has anybody installed transom wedges to rectify my issues on my exact rig setup?

[Moonlighter]

Please read the "sticky" thread near the top of this forum that tells you how to check engine hieght and select the right prop. We wrote this thread to save having to repeat the same info all the time.

Here is a link to take you directly to it:

http://www.suzukioutboardforum.com/s...ight-prop.html

It answers all your questions, and the second post even tells you one easy method of lifting your motor yourself.

A couple of comments - when trimmed all the way in (down) it is totally normal for the keading edge of the cav plate to be lower than the trailing end.

It is only when the motor is trimmed "neutral" that the cav plate will be running parralel to the hull.

If you read the earlier posts in this thread, ypu will see the comments about motors that are too low throwing a lot of water around and causing porpoising. Yours sounds very much the same.

Again, read the sticky thread it tells you how the cav plate should be running at a cruise speed.

Once you have read that if you have any further questions come back and ask.