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View Full Version : 3 or 4 blade for skiing?



moomba wannabe
02-04-2010, 12:02 PM
Ive not seen this answered directly so I will simply ask it; is there much of a difference in the wake from a 3 vs. 4 blade prop on a direct drive? I have an 05 Outback that came with a 4 blade and I mainly ski. The wake is pretty nice but Ive skiied behind other DD's with better (smaller) wakes so I'm wondering if its worth it for me to change to a 3 blade.

Mikey
02-04-2010, 09:46 PM
I have a three blade on mine for skiing.I've never had a four but i've heard others mention more bump at 22 using the fourblade.Four blade is/was the wakeboard upgrade prop when i purchased my boat . I ski so i stuck with 3 blade and no issues.

deerfield
02-04-2010, 10:26 PM
I have an 05 Outback that came with a 4 blade and I mainly ski....so I'm wondering if its worth it for me to change to a 3 blade.

moomba wannabe - Interesting. I ski, so bought an Outback ('07) that came from the factory with a 3 blade prop, which was the set up used to certify the '07 Outback for three=event towing. Wonder why yours has a 4-blade prop? - Deerfield

phospher
02-05-2010, 01:15 PM
Prop is not going to change your wake, at least not any measurable amount. it's just a tradeoff between hole shot and top speed. people who weight there boat a lot tend to prefer the 4 blade as it will get out of the hole quicker and probably will allow them to control speed a little better.

maxpower220
02-05-2010, 03:34 PM
Actually, the 4 bladed prop will slightly alter the table and wash that your wake makes at slalom speeds. I had a MC with a 4 blade and loved it. Tried a 3 blade on it and noticed a slight difference crossing the wake.
I have not tried a 4 blade on the Moomba, but I would like to see the difference. For sure, each hull will react differently to props, so you can't say just because this MC (CC or Bu) reacts like this, then the Outback will also.

Someone buy both and run a test, please.

phospher
02-05-2010, 04:50 PM
interesting..

moomba wannabe
02-05-2010, 05:05 PM
moomba wannabe - Interesting. I ski, so bought an Outback ('07) that came from the factory with a 3 blade prop, which was the set up used to certify the '07 Outback for three=event towing. Wonder why yours has a 4-blade prop? - Deerfield

I should clarify - It came new to me last summer with the 4 blade, so could have been any number of reasons-original purchaser upgraded to the 4 blade or replaced the original with a 4 blade. I obviously would be very interested in a test myself but if noone has or does one and I end up with a 3 blade I will definetely share my comparison. I do have alot of other improvements towards the front of the line so may be awhile.

Laz
02-05-2010, 10:22 PM
Hi. I have a 2007 Outback and got a new prop last year.

See my previous thread:

http://moomba.com/msgboard/showthread.php?t=8937

dru1974
02-05-2010, 11:57 PM
My dealer said when I pick my boat up in april he would put whatever prop i wanted on it and he would just put the one he takes off back into there stock. was told by oj to go with a 14 by 14 four blade for top end as I enjoy barefooting and my new boat is a mob ls

viking
02-06-2010, 12:44 AM
Hi. I have a 2007 Outback and got a new prop last year.

See my previous thread:

http://moomba.com/msgboard/showthread.php?t=8937

Laz,
Is that a 4 blade or three you purchased?
thanx

barefooterh2o
02-06-2010, 01:08 AM
I'm on a water ski team for the last 10 years so I've skied behind many inboards. Wakeboard boats can use either 3 or 4 blade depending on the size of boat. 4 blade generally will give you a better hole shot on a bigger boat. Some slalom course skiers like the 4 blade but most that I ski with, use a 3 blade. There is a difference in prop wash between a 3 and 4 blade props. But seems not to affect slalom course skiing as much as barefooting. Barefoot skiers go with the 3 blade for the top end speed and the prop wash is little nicer especially going backwards. 4 blade props will not have the top end speed as a 3 blade. If you are doing the slalom course fine with a 4 blade prop, than keep it.

deepcove
02-06-2010, 01:24 AM
That is old school thinking. With todays modern cnc'd props you can get more blade area out of a 3 blade than previous welded versions as you can balance it perfectly with cnc machining. 4 blades became popular as you could get more surface area than previous 3 blades and keep it balanced, therefore giving you more surface area. ACME's recomended prop for wakeboarding with my LS is a 3 blade. My stock prop was a non cnc'd 4 blade. My 4 blade has more top end and I find I have a softer bump with my 4 blade. Therefore my 4 blade is for skiing and 3 blade for skating and surfing.

As for what works better 3 or 4 blade for skiing.....every boat will react differently so there is no one answer to this question.

kaneboats
02-06-2010, 02:37 AM
OK, that's the first time I've heard that. The 4 blade for skiing and the 3 blade for surfing. This just goes to show you it is the nature of the individual prop and the application and there is no set rule for 4 vs. 3 blades.

We ski a bit, board a bit with a little weight on and surf with a lot of weight on. The OJ 3 blade performs nicely for everything we do. No complaints. Maybe the right prop for the boat is more important than trying to match the right prop to the application-- at least with certain boats with certain activities (DD across the board???).

Laz
02-06-2010, 11:42 AM
Laz,
Is that a 4 blade or three you purchased?
thanx

It's a 3-blade. We use our boat almost exclusively for skiing. Even my skeptical wife has noticed an improvement.

Laz
02-06-2010, 11:52 AM
We were not actually having any problems with our old 13x13 3-blade OJ. It worked very well. However, I bought the ACME prop as a backup and decided to try it out since it was very easy to change props.

I was quite surprised with the performance improvement as I expected no real difference.

We are very sensitive to (and impressed with) the skiing characteristics of our boat but our wakeboarding skills are pathetic, so I can't really comment about that.

Also, any wakesurfing we do is entirely unintentional.

moomba wannabe
02-06-2010, 06:13 PM
We were not actually having any problems with our old 13x13 3-blade OJ. It worked very well. However, I bought the ACME prop as a backup and decided to try it out since it was very easy to change props.

I was quite surprised with the performance improvement as I expected no real difference.

We are very sensitive to (and impressed with) the skiing characteristics of our boat but our wakeboarding skills are pathetic, so I can't really comment about that.

Also, any wakesurfing we do is entirely unintentional.

Ditto here, my wakeboarding skills are rather weak too. I would prefer to have the boat set up for skiing as I enjoy that more, as whats pulling me on a board will really have minimal effect on my ability! I will have to consider your Acme set-up. Can you confirm the wake is nice, I have a decent though fairly small bump behind my 4 blade.

viking
02-07-2010, 01:08 AM
Laz,
Whats the altitude of Toronto? Want to compare with Billings, MT because if it's in the neighborhood I might consider the same ACME as a 2nd (or primary) prop. as well. I posted a question in another thread about a second prop. as I have another RH 4blade to trade in with an ACME dealer :)

Sorry.......guess I could just google it! What was I thinking? I guess I just like to talk to you guys and gals :)

BensonWdby
02-07-2010, 10:55 AM
I have a 99 Mobius that came with an OJ 4 blade. Seemed to work fine for slalom. I hit something with it and was recommended to an ACME 3 blade by multiple sources. Called ACME and there was only one prop they would sell me for the specific boat/motor combo. I bought it and have used both. I have not really noticed much of a difference. I could not even tell you which I hae on the boat at the moment. Just depends on which has had the most dings recently. We do have a bit of a 22 off bump. My solution is just to go faster and go to 28-38 off depending on water conditions. Pretty much alwasy at 34 mph these days, vs. 30 for many-many years prior.

Sled491
02-08-2010, 11:03 PM
I run a 4 blade 13 x13 but think the stock 3 blade CNC prop was smoother. The big difference between a 3 blade and 4 blade on a ski boat for skiers is the bump, or rooster directly behind the boat. Then new props that are being recommended can eliminate most of this. All depends on how you use your boat. We ski every morning, 34 - 36 mph depending on whos up. But come late afternoons or evenings or weekends its the kids time and speed get reduced and the great slalom wake I enjoy every morning now gets to look a little nasty.

I'm not sure there is a perfect prop for all aspects, but there might be one that suits your needs best as long as your requirments don't go to wide.

Laz
02-13-2010, 10:36 PM
I don't know what the altitude is in Toronto, but we are pretty close to sea level. I haven't noticed any difference in the wake between the 3 blade 13x13 OJ and new ACME prop. I've only noticed a better hole shot and more efficiency. Also the boat seems to slow less turning 180 degrees after a pass through the course.

Laz