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View Full Version : 05 XLV tops out at 35mph.. need help!!



lift yer skirt
08-28-2008, 11:51 PM
So like the title says my 05 XLV GG tops out at 35mph and 4700 rpm. I have the 14.7X17.5 4 blade brass prop. With no water in the bags and 5 people in the boat its all I can do to pull a skier up.

Is this a normal speed for this boat? Or is there more to be had with a prop change? I am really disapointed in the performance of my boat. The malibu's and mastercrafts leave me in their wake. PLEASE Help me!!!!

I am thinking about changing to a 14.25X14 4 blade acme prop. I should see some better low end but thats not gonna help me with the top end.. I am soo confused...

Again please help!!!

jmvotto
08-29-2008, 12:01 AM
I have the 13.7x17.5 xmp 4 blade cnc oj in my 07 obv at that tops out at 47 48, mph with two people and no ballast. Hole shot is fine.

jimmobius
08-29-2008, 01:04 AM
I have a 05 Mobius lsv, switched to a 13.5 x 16 Acme #537 prop. Works great at mile high altitude and 3600' at Lake Powell. Top speed 44 +- and 4800 rpm. Will pull wakeboarder up with 7 people on board. Had the same prop on as yours and engine would not rev up to specs . Shoud tach out to 5000 rpm. Jim .

deafgoose
08-29-2008, 02:33 AM
My OBV came with the 13x17 OJ prop and I upgraded to the 14x14 OJ and lost 6mph on my top end. I could hit 46mph with the stock prop but I can only manage 40mph with the new one.

The holeshot is night and day and I could never live with the 13x17 ever again.

14x14 FTW!!!

ian ashton
08-29-2008, 06:46 AM
Just curious; how fast do you guys get pulled up wakeboarding? I like it nice and slow, so I'm not sure why you'd sacrafice top end for a faster holeshot. It seems like on a wakeboard you can pop up at about 6 mph, or at least I can, LOL.

lift yer skirt
08-29-2008, 08:42 AM
ian i agree about a wake boarder but when pulling a skier you need some grunt to get them out of the wate....

So far it looks like the consensus is my problems should be solved with a new prop....


Also info that might be useful to help me. Boat is the 340hp, and I am skiing at 4-6500 feet.

tazz3069
08-29-2008, 08:57 AM
Lift yer skirt--
Go to a websight www.boarditup.com. Some of the members here told me to contact them about my problems with my boat. They suggested an ACME prop for me. I put it on, loaded the boat up with ballast and 9 people, and let me tell you. I am very happy. Give these guys a try. I believe the gentleman that I spoke with was Jim. Again you will not be diappointed.
Tazz

aintskeered
08-29-2008, 10:00 AM
Lift yer skirt, Also check out or fill out the boat loading card for ACME then contact them. They seem pretty good at balancing boat/prop and application.

More weight--less top speed, less hole shot

More top end --less hole shot

More altitude-- Less air/less HP/ less hole shot/less top end Gotta reprop!

My 07 Lsv I have Oj prop 14.24-14 Works good wakeboarding,and surfing but I only get 35-36 WOT. I am at 5500 feet msl and throw in a warm day. The density altitude( Boat engine preformance) suffers. The engine is running like it is at 8500-9500. It works out to be only getting around 57% of the HP it would at sea level to the prop.

yearround
08-29-2008, 11:03 AM
we have an 08 LSV with the wakeboard prop, the 14.25x14 4 blade. we are at 5600, about the same as aintskeed, just opposite side of the mountains, our top speed is about 36.

hole shot for ski is great even with 8 people in the boat, have talked with prop shop and they talked to OJ, OJ said that the LSV hull is only good for 36, with any prop we put on. most of the people here who have the OB have said they hit 45+, i do not recall many LSV people saying they go over 36. don't know about the XLV, i don't remember what they have said if different than you.

tazz, how fast are you going with the acme?

Ian Brantford
08-31-2008, 10:04 PM
So like the title says my 05 XLV GG tops out at 35mph and 4700 rpm. I have the 14.7X17.5 4 blade brass prop. With no water in the bags and 5 people in the boat its all I can do to pull a skier up.

Is this a normal speed for this boat? Or is there more to be had with a prop change? I am really disapointed in the performance of my boat. The malibu's and mastercrafts leave me in their wake. PLEASE Help me!!!!

I am thinking about changing to a 14.25X14 4 blade acme prop. I should see some better low end but thats not gonna help me with the top end.. I am soo confused...

Again please help!!!

While a prop change will probably help you (and would be recommended with the GG ballast), you should be getting more from your boat. Which engine do you have? I have an 05 XLV as well. It is not the GG version, but I have upgraded it to a 14" prop and 2000+lbs ballast. The original thread on this topic has disappeared, but we mentioned it again at the end of this thread: http://www.moomba.com/msgboard/showthread.php?p=18870#post18870 .

I am not sure how you ended up with a 17.5"-pitch prop on a GG boat, but that is really too high for a GG ballast. a 14" prop will be much better. With such a prop, you should expect an unweighted top speed of 38-40MPH if you have the 340MPI engine.

However, I am concerned about your boat's unweighted performance. Unweighted, yours would be virtually the same as my original configuration, and you should expect to get about 40MPH@4800 with the 325MPI engine, or 44MPH@5200 with the 340MPI engine. You should be able to pull up a rider with ease and accelerate so fast that unwary passengers fall over. Based on your description, I think that your boat has a mechanical problem, though it is very difficult to diagnose a general power problem remotely.

lift yer skirt
08-31-2008, 10:30 PM
Ian thanks for the post. My boat is the 340mpi and I am riding at 4000-6000 ft. The only thing I can think is that the prop was for a sea level boat that ended up in the high elevation.

I have been on the phone with a few different Moomba dealer/mechanic's over the last few days. I also talked to the guys at acme and the guys from boarditup.com.

Everyone agrees that the prop I should be using is an acme 14.25X14.5 1.50cup. (ot the 1.05cup) They also all seem to think that at the elevation I am riding that my speed is probably about right. Considering the prop I now have on it. They are telling me that with the 1.50cup this new prop wont effect the top end much but will really help the bottom..

I am taking the boat to sea level after I do the prop change so we will see the top speed down low.
Thanks for everyone for there quick help.
Dusty

Ian Brantford
09-02-2008, 12:36 AM
Ian thanks for the post. My boat is the 340mpi and I am riding at 4000-6000 ft. The only thing I can think is that the prop was for a sea level boat that ended up in the high elevation.


You are welcome. You just reminded me about a comment that my dealer made when I was thinking about going straight to the 14" prop... he said that it was really just for higher elevations. Now, his advice was wrong in that, with the original Gravity III ballast plus a boatload of people, the original prop is still kind of high-pitch on the XLV. However, I can now see what he was thinking about. Maybe your results are to be expected at your usual altitude. Still, a loss of 20% seems like a lot. Best of luck with your high and low altitude testing.

Also, at any altitude, please be aware that those extra 400RPM at the top end on the 340MPI engine come at the price of very high fuel consumption. The XLV's hull simply is not made to be move very fast -- it is made to dig a nice trench in a lake at wakeboarding speeds. So, don't carry out your top speed tests for too long!

jimmobius
09-02-2008, 12:37 AM
Hello, another thing you might want to do is verify your speedometers are correct with a gps. Mine were off 4 mph when I bought the boat. It does change on occasion. Jim.