1.8 HO VXR/VXS N.A. 7200rpm Max Question/SOLUTION

[ksalles]

Long story short, I purchased a 2017 VXR with 30hrs for my daughter to ride and as a cruiser, and it's a PIG. It spins 7200rpm max and feels lazy. I've did the TJ exhaust mod, ribbon delete, new plugs, corrected the oil level...and still, 7200rpm. I pulled the pump and inspected the prop as well as changed the wear ring...same thing 7200rpm. I even went as far as testing a spare pump i had with a Solas Concord 13/19 and guess what......same 7200RPM. The ski cavitates bad out the hole with either prop setup, so today I pulled the transom and prepped the area install the larger intake grate supports, as well as gill the void in the liner prior to installation.

With all that said, I've seen several references to some of these skis stuck at 7200rpm for some odd reason, but never seen anything definitive as to what is causing it. I've ridden 3 other ones locally, and they all perform as to what I'd expect them to...closer to 7600rpm and they feel night and day different from this one. Thanks in advance for any suggestions on what to look for, or expect. Keith

[Orange FZS]

Have you checked the condition of the air filter?

[ksalles]

air filter comparison on page 3

[Diegosan]

I just pulled the filter. it looks about the same as the one I looked at when i upgraded my GP1800. This is what it looks like...

The distortion of the filter element indicates extra vaccum from the intake as though it is hard for it to suck air through. I see this a lot when the filter gets wet which may or may not be the case, certainly the yellow filter element should not look as distorted as that.

[Diegosan]

Also check for an exhaust leak at all of the clamps in the exhaust system. The more hidden ones can break if used in salt water or on the odd occasion I have seen the hoses not installed correctly over the pipes as well.

[ksalles]

Thank you...I'm in the process of updating the intake grate brackets, so fortunately I have all the exhaust clamps staring me in the face. Most of them already off, being I had to remove the suppression box and tube for the brackets, and transom removal to reseal and straighten it.

Also check for an exhaust leak at all of the clamps in the exhaust system. The more hidden ones can break if used in salt water or on the odd occasion I have seen the hoses not installed correctly over the pipes as well.

[Mr. GP1800]

I’m interested to see what comes of this. My VXR seems to be the same way. It ran 64 mph the first day I had it out. I changed the ride plate did the ribbon delete and power filter. Saw no gains from that. I did run it 65 mph last spring. I then installed a riva intake grate and I can’t touch 62 on it anymore. It’s confusing to me.

[xkon]

I'm interested to see what comes of this. My VXR seems to be the same way. It ran 64 mph the first day I had it out. I changed the ride plate did the ribbon delete and power filter. Saw no gains from that. I did run it 65 mph last spring. I then installed a riva intake grate and I can't touch 62 on it anymore. It's confusing to me.

I lost 2-3 mph on my vxr when I installed the R&D intake grate. Lost another 1-2 mph when i installed the worx sponsons set down low.

Before those mods, with the riva ride plate, ribbon delete, intake, and exhaust mod I got a consistent 67 with the occasional 68-69 in the beginning/end of the season when it was cooler out. Stock was running about 64.

[Mr. GP1800]

I lost 2-3 mph on my vxr when I installed the R&D intake grate. Lost another 1-2 mph when i installed the worx sponsons set down low.

Before those mods, with the riva ride plate, ribbon delete, intake, and exhaust mod I got a consistent 67 with the occasional 68-69 in the beginning/end of the season when it was cooler out. Stock was running about 64.

im tempted to throw the stock grate back on mine. I have a rear exhaust kit for it in the box but I haven’t decided if I want to install it yet.

[ksalles]

I decided to pull the transom and grate and completely reseal and straighten everything. While I had the ski apart, I also made an intake. Hopefully I'll be testing it soon, but in the meantime I've read several skis who had this mysterious 7200 rpm problem and low top speed along with cavitation. As mentioned, I couldn't find any definitive reasons why this is happening. A couple of guys took their ski to the dealer and they even said they should turn at least 7600rpm. It's definitely odd.

I’m interested to see what comes of this. My VXR seems to be the same way. It ran 64 mph the first day I had it out. I changed the ride plate did the ribbon delete and power filter. Saw no gains from that. I did run it 65 mph last spring. I then installed a riva intake grate and I can’t touch 62 on it anymore. It’s confusing to me.

[2fast4u]

Keith, Have you done a compression test yet. Since this is a NA motor the slightest loss in compression can cause this motor not to reach max rpms, Tommy Jordan

[ksalles]

Problem solved...I'm about to post results and the solution. Thank you Tommy. Needless to say, I'm thrilled.

[ksalles]

I removed my air filter and it looked compromised. Riva was closed, and I have a bunch of parts laying around. I re purposed the stock SHO intake tube and some garage fabrication to develop my own intake. The ski seems to be near, or on the rev limiter with the stock prop, and the air is horrible today. Needless to say, it was choked up. I'll play with props and nozzles another time...I just wanted it to at least rev first. Excuse the poor videos, I was trying to video with one hand and ride and my fingers shut one off mid run.

*ALSO, I did add the plate from a 19' up GP1800 at the same time as I did the intake. I took the one off my GP to test it on this ski. Needless to say, I ordered another one.

[ksalles]

And the air is horrible today, so I'm overly pleased.

[ksalles]

https://youtu.be/ncCHu5tE-gk

https://youtu.be/3d3lIWhSWYo

https://youtu.be/_iHwFQkA5IM