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boo4381
09-24-2007, 03:07 PM
I have a 05 x-star with a 14.5 x 22 prop. Does anyone know if this is the stock prop for boat with the 8.1 Litre 450hp motor? It doesn't seem to pull very well right now. Thanks in advance

MYMC
09-24-2007, 03:47 PM
Yes, and that doesnt make sense...empty with that prop anywhere near sea-level it should be capable of pulling the handle out of your hands.

WakePowell
10-08-2007, 05:06 PM
MYMC - Do you have a prop suggestion for a loaded X-Star or X-45 with the L18 engine? I am considering going to a 13.7 x 17 or 14.5 x 14.25.

MYMC
10-08-2007, 06:00 PM
MYMC - Do you have a prop suggestion for a loaded X-Star or X-45 with the L18 engine? I am considering going to a 13.7 x 17 or 14.5 x 14.25.
13.7x17.5 is really pretty nice with it... you have tons of bottom and still should be able to run wide open without hitting rev-limit. If you want a little more then do the 13.7x17. I'm not a fan of the 14.5X14.25 on L-18 boats.

magnum
10-08-2007, 10:35 PM
Boo, how do you like your x-star with that engine, I am going to be in the market sometime next spring and have test drove an X30 with the MCX and an X45 with the LY6 but I am leaning toward the 450 HP in some used X-stars that I have seen . I have been thru boats that were under powered and don't want to go back there. what is your top speed with that prop? . Also do you have plenty of room in the x-star?

Springer
10-18-2007, 09:21 PM
Have you used both props on your boat with the 8 litre? Is yours the 450 HP motor?

WakePowell
10-19-2007, 09:48 AM
I used the 14.5x14.25 on my X-45 last weekend and it was definately too low for the L-18. With full factory ballast and five guys it would jump out of the hole but for wakeboarding the motor was reving 3,800 to 4,500 RPM.

Hopefully my dealer will swap a new 14.5x22 for a 13.7x17 since I have two of the larger props.

johkur
09-19-2008, 08:07 PM
I've got an 8.1L X45. After some initial questions, MC shipped a 14.75x17.5 prop. with 2 people and no ballast top speed is about 45mph. With ballast and loaded, you don't know the difference, its great for out of the hole, and we seem to use about 4-5 gals/hr rough estimate. My seadoo (RXT, 200+hp) also uses about 4-5 gals/hr, so I have no complaints about mpg on this 450hp engine either.

bainez23
09-22-2008, 06:16 PM
13.7x17.5 is really pretty nice with it... you have tons of bottom and still should be able to run wide open without hitting rev-limit. If you want a little more then do the 13.7x17. I'm not a fan of the 14.5X14.25 on L-18 boats.

MYMC do you have a suggestion for an 2003 x-2 loaded down?

flipper
09-22-2008, 06:22 PM
hit up eric@oj. He'll be able to set you up with the right stuff

bainez23
09-22-2008, 06:40 PM
hit up eric@oj. He'll be able to set you up with the right stuff

thanks i will

TMCNo1
09-22-2008, 07:16 PM
hit up eric@oj. He'll be able to set you up with the right stuff


Here, http://www.ojprops.com/contact_us

johkur
09-01-2009, 03:16 PM
My L18 2008 X45 with the 2 separate silentmaster exhausts and wide open pipes (stainless, no flaps), seems to perform very well with the 14.75x17.5. It often pulls boarders out too fast, even with ballast and 8 people on the boat (fine), but top end is 42mph, and I think I'm using more gas than I need. I've noticed that rpm is usually about 1000rpm higher than mph, so at 22mph we're at 3200 rpm, etc. Maybe this is not where we want to be on the power curve? I expected a big engine to need less rpms than a smaller engine for same speed, which would help fuel efficiency.

Is there another prop that might still give us good performance out of the hole, but maybe help gph? Most boats were having those baffles in the tips instead of silentmaster for the years you said couldn't handle the 14.5x22, so maybe the silentmasters and the open tips (and without even flaps) gives the engine the ability to use a different prop?

EJ OJPROP
09-01-2009, 03:29 PM
Is the 3200 RPM @ 22MPH and 4s MPH with the ballast tanks full?

MCRambo1
09-01-2009, 04:19 PM
I have been thru boats that were under powered and don't want to go back there. what is your top speed with that prop? . Also do you have plenty of room in the x-star?[/QUOTE]

We have an '08 X-Star with the MCX, and we LOAD IT DOWN! We've had no problems with it, use 14.5 x 14.25 prop. You do get a little more power out of the bigger engines, nothing incredibly noticable. But there is a considerable difference in fuel consumption, especially if you're cruising around.

TallRedRider
09-01-2009, 04:27 PM
MYMC - Do you have a prop suggestion for a loaded X-Star or X-45 with the L18 engine? I am considering going to a 13.7 x 17 or 14.5 x 14.25.

I have had a 13.7 X 19.5 on my X45 and do not recommend it with the 8.1L. I felt the RPM's were too high for the amount of ballast I was running. It was not terrible, but I thought that 3500 RPM wakeboarding with stock ballast only might be a little high. I think the 13.7 X 17 would be running at even higher RPMs for the X45. Shameless plug: The 13.7 X 19.5 is for sale in the market if anyone is interested and it would make a terrific backup if you did not like it for the primary prop. Definitely would work to keep the boat going while the other prop is at the shop.

I swapped it out for the ACME 14.5 X 16 and the boat turned into a freaking rocket, even with a good amount of supplemental ballast. It will pull your arms out even when weighted a fair amount extra. However, it introduced a vibration that I did not have before and another ACME of the same size failed to fix it as well. I think it is cavitation, and nothing might help.

Eric recommended I try the OJ 14.75 X 15.5. I will be trying that next week. Hopefully I will have some news to report back.

TallRedRider
09-01-2009, 04:28 PM
I have been thru boats that were under powered and don't want to go back there. what is your top speed with that prop? . Also do you have plenty of room in the x-star?

We have an '08 X-Star with the MCX, and we LOAD IT DOWN! We've had no problems with it, use 14.5 x 14.25 prop. You do get a little more power out of the bigger engines, nothing incredibly noticable. But there is a considerable difference in fuel consumption, especially if you're cruising around.[/QUOTE]

I think Rambo is right. My wakeboarding fuel consumption is not much different than 6-8 GPH. But run around the lake at 33 MPH and get ready to see what it feels like to fill a 90 gallon gas tank.

johkur
09-22-2009, 08:27 PM
Is the 3200 RPM @ 22MPH and 4s MPH with the ballast tanks full?

With ballast, the difference between mph and rpm is about 1000 rpm extra, without ballast, its about 800rpm extra. I'm thinking this is because the L18 barely notices the load, while other smaller engines probably have a bigger gap between ballast and no ballast rpm's for the same speed.

mpabreo
09-23-2009, 12:26 PM
Anyone have Eric's email address at OJ? The contact us form on the site wont let me fill anything in..

Thanks.

johkur
09-23-2009, 12:52 PM
I have had a 13.7 X 19.5 on my X45 and do not recommend it with the 8.1L. I felt the RPM's were too high for the amount of ballast I was running. It was not terrible, but I thought that 3500 RPM wakeboarding with stock ballast only might be a little high. I think the 13.7 X 17 would be running at even higher RPMs for the X45. Shameless plug: The 13.7 X 19.5 is for sale in the market if anyone is interested and it would make a terrific backup if you did not like it for the primary prop. Definitely would work to keep the boat going while the other prop is at the shop.

I swapped it out for the ACME 14.5 X 16 and the boat turned into a freaking rocket, even with a good amount of supplemental ballast. It will pull your arms out even when weighted a fair amount extra. However, it introduced a vibration that I did not have before and another ACME of the same size failed to fix it as well. I think it is cavitation, and nothing might help.

Eric recommended I try the OJ 14.75 X 15.5. I will be trying that next week. Hopefully I will have some news to report back.

I use a 14.75x17.5 on my L18 X45, and with stock ballast, wakeboarding at 22mph has us at 4200 rpm. (4000rpm without ballast as per my response to OJ). So if you didn't like 3500rpm, I doubt you'll like the 14.75x17.5 at 4200rpm). Or, what did you find, if you already tried this? I'm thinking the newer engines and exhaust are again doing better, like the 2006 X45 L18's, which can handle more prop than the stock 2007-2008 with inline baffles that stifled the engines (and perhaps other differences).

According to OJ, the 14.5x22 was developed for the 2006L18X45, I assume for wakeboarding and loaded holeshot as well (see http://mastercraft.com/teamtalk/showthread.php?t=22388&highlight=prop for further details and links). I'm thinking the L18 X45 is now back where it should be in terms of performance (given the higher rpm's with the 14.75x17.5), and now might be able to handle the 14.x5x22 like the 06 L18x45 could). Am I understanding that right, given 4200rpm with load and 14.75x17.5 and Tallredrider's experience at 3500rpm with the 13.7x19.5?

I'm thinking the 14.75x19.5 is the next thing to try (if it exists), or the 14.5x22 if more interest in top end or even more trust that the engine can get out of the hole. And either would give us less rpm's, and thus less gph (I think).

EJ OJPROP
09-23-2009, 01:30 PM
Anyone have Eric's email address at OJ? The contact us form on the site wont let me fill anything in..

Thanks.

eric@ojprops.com or 800-359-9730

Springer
09-28-2009, 05:31 AM
L18 with full ballast....5-7 people......fly high ballast full or empty....14.75 X 15.5 LC XMP EDGE 4-blade prop OJ is awesome. Will pull the same boat...same motor with the 17.5 prop by 4 boat lengths out of the hole right up to 40 mph. At 3000 rpm runs around 26 mph. Fuel milage similar if you keep the rpm the same. Cruise a little slower...enjoy the sights a little more. This combo is the one as the boat and motor are magic!!!!

Ole Miss Rebels
09-28-2009, 01:46 PM
My L18 2008 X45 with the 2 separate silentmaster exhausts and wide open pipes (stainless, no flaps), seems to perform very well with the 14.75x17.5. It often pulls boarders out too fast, even with ballast and 8 people on the boat (fine), but top end is 42mph, and I think I'm using more gas than I need. I've noticed that rpm is usually about 1000rpm higher than mph, so at 22mph we're at 3200 rpm, etc. Maybe this is not where we want to be on the power curve? I expected a big engine to need less rpms than a smaller engine for same speed, which would help fuel efficiency.

Is there another prop that might still give us good performance out of the hole, but maybe help gph? Most boats were having those baffles in the tips instead of silentmaster for the years you said couldn't handle the 14.5x22, so maybe the silentmasters and the open tips (and without even flaps) gives the engine the ability to use a different prop?

let me get this straight. your boat came from the factory with the dual silent-master mufflers and NO (zero) flaps over the tips? Is that correct? I am surprised that the boat has no flappers as i thought all boats had some type of preventitive measures to keep water from backing up into the engine. please correct me if i am wrong or if you took the flappers off as opposed to the boat coming from the factory with no flappers and wide-open tips. thanks.

johkur
09-28-2009, 02:30 PM
L18 with full ballast....5-7 people......fly high ballast full or empty....14.75 X 15.5 LC XMP EDGE 4-blade prop OJ is awesome. Will pull the same boat...same motor with the 17.5 prop by 4 boat lengths out of the hole right up to 40 mph. At 3000 rpm runs around 26 mph. Fuel milage similar if you keep the rpm the same. Cruise a little slower...enjoy the sights a little more. This combo is the one as the boat and motor are magic!!!!


What boat is this? My X45 L18 with 14.75x17.5 is at 4800rpm for 26mph. I would expect to have lower rpm for same speed than the 14.75x15.5 unless there's something else different.

johkur
09-28-2009, 02:38 PM
let me get this straight. your boat came from the factory with the dual silent-master mufflers and NO (zero) flaps over the tips? Is that correct? I am surprised that the boat has no flappers as i thought all boats had some type of preventitive measures to keep water from backing up into the engine. please correct me if i am wrong or if you took the flappers off as opposed to the boat coming from the factory with no flappers and wide-open tips. thanks.

When I bought my boat, I asked to make sure that it made the European noise standards as a requirement to going with the L18. I also liked that stainless exhaust tips that were pictured in the brochure, etc. When the boat got to the dealer, it had rubber flappers and no real exhaust tips, and it had baffles. I asked MC about this, and also noted that in between my purchase and shipment build-a-boat added a separate charge for silentmasters (which I had expected in my boat), and that the European package always included silentmasters, and that silentmasters were needed to meet the european noise standard. I also have muskrats that eat all rubber in the water (including sinking a boat once by eating the I/O bellows), and so there was no way that I could buy a boat with exposed rubber near the waterline. So before I took the boat and finished the purchase, they replaced the exhaust tips with the stainless tips and put in the 2 silentmasters. They also removed the baffles as part of the exhaust change since the L18 gets stifled with baffles and especially can't be used in combination with the silentmaster. They did not include the MC logo plate in the tips either, as those had been falling off, and also would block exhaust flow.

BUT, we kept losing antifreeze. And both exhaust manifolds had cracks, but I'm assured that this was NOT due to the lack of the preventive features you mentioned. I was told by MC that the silentmaster itself prevents water from backing up into the exhaust manifolds, and so a flap is not needed. I actually would have liked some sort of metal flap to direct noise downwards, but could not find something easy to install myself.

Springer
09-29-2009, 12:50 AM
My boat with the 15.5 prop is the xstar. Something is up if you are running 4800 rpm at 26 mph with a L18 You should be running 2800 rpm at that speed

johkur
09-30-2009, 12:38 PM
I've got to correct myself. My L18x45 with the 14.75x17.5 is running about 1000rpm higher than speed at wakeboarding speeds (before the boat planes out due to the 2nd step of the hull). So at 22mph, we're at 3200rpm with ballast, 3000rpm without ballast. At one point I mentioned 2000rpm difference instead, that was wrong. This is a 2008 with open tips and silentmasters, to help people compute what prop they might want for their type engine.