Calling all 4x4 hill marine owners...any vibration?

J3ff

I've noticed some vibration starting around the time I got the new props put on.. it's slight, but it's there and is easy to feel at the right RPM.  I do NOT remember it being there before and now someone else is reporting the same thing.  Seems to be strongest right before pushing the throttle up to get on plane, somewhere around 2600-3600 RPMs... anyone else notice this?

Especially interested if you have ZERO vibration in the boat with 4x4's..

Robs_232

I put these on my boat and don't have any vibration and I used a torque wrench. I don't remember them showing a prop timing with the 4 x 4 props.

Black_Diamond

The Merc manual for installing props on the B-III specifies to click them. I did with my 4x4’s. Lots of discussion about to do or not. I figured the reasoning is worthwhile. 

Dream_Inn

Well, I have the B-2 4X4s, but haven't noticed any vibration at all.

Handymans342

Me neither. 

reneechris14

Just me thinking out loud. When the drive is all the way down the drive hits the pin on the transom assembly see where the plastic shims are the paint is missing. If you just touch the trim up a touch see if the sound goes away. Those other dudes have Bravo2's so maybe the 8 blades put out more torque. The RPM range suggest the biggest power zone you know just coming on plane.

Black_Diamond

Zero with my 4X4’s on my B-III’s

Willhound

Any custom prop shop I've ever heard of spin tests their props before going out the door so I doubt its the props. But...the extra force being applied to your drive might be causing something else to vibrate that wasn't previously noticeable. What that is could be a number of things, shafts, bearings, gimbal etc.

Michael T

Sometimes there is very, very minute vibration. We are talking about gear sets and clutches BUT IMO there should be no vibration that you can feel.

If you have dropped to a lower pitch (diameter and rake being the same) there should be less stress on your gear sets.

Agree with @Willhound.....but is Hill Marine really a "custom" shop or are they more mass producing now that they are a bigger company. I have purchased expensive SS props before and have had to get them blueprinted even though they were supposedly "custom".

The only custom props I ever received that were beyond reproach were from an outfit called Indiana Propeller. I don't think they are in business still.

Willhound

Hmm...I made the statement without actually knowing what Hill Marine's testing practices are. But I would hope they have some kind of balance test before shipping. @Michael T I agree that the lower pitch may help lessen strain but I was thinking more about the added stress added to gear train because of less prop slippage? Thoughts?

Michael T

@Willhound.....now you have m reaching back to the days when I was friggin' around with props every weekend with my buddies LOL .....so, prop slippage IMO should not actually stress a drive - it will, of course, result in higher rpms , lower mph and higher gph. What IMO would stress everything more would be a prop (due to incorrect pitch, diameter or rake) that would cause the engine to top-out (WOT) below its rated rpm band, THAT would be bad. 

IF and I say IF I had to choose between under revving or over revving in my rpm band I'd pick over revving and watch the tach at WOT.

That said there is so much choice these days that the correct pitch, number of blades or some custom tuning should put almost anything in its right operating range.

Yes, @Willhound, I do think good manufacturers test props - maybe not every one, but random to ensure quality. Great ones test them all but those are expensive. I have found Mercruiser props to be better than most off the shelf units as their quality seems more consistent.

Bottom line to me is that with a noticeable vibration I might check the run-out of the shaft or even the installation of the prop - for example proper thrust washer, even another set of props before I started blue printing props.

Black_Diamond

Might be worth checking the torque on the prop nuts.  

laureniac1

Zero issues with my Hill marine 4x4 on my 270. I agree with Black Diamond get a torque wrench on them. Harbor freight lol I use it twice a year 

J3ff

I've actually got one and thought I used it when I put them on. Hmmmm.