To get the best answer you should give the experts on the forum a little more information. What is the RPM @ 40, have you check your belt for wear, is it running smooth or cutting out? JMHO

 

Txs SeaDog. I’ll get the RPMs later today. The belt is new(er), maybe 100 miles on it. It runs smooth. Only way I can describe the feeling is it feels like it has a governor (sp) and just tops out. What is top speed on the machine?

 

I should have asked have you verified you are in H gear and not L just wondering

 

Good point! I am in H gear though. Since I am clearly a "newbie" what is the top RPM I should expect? I don't have an area near me, without having to trailer, that I have a straight shot on can stay on the gas for more that 30 secs or so without having to reduce speed for turns. How long should it take to get up to top speed, baring no additional barriers to tend to? I am also running air pressure on my 30x10x14 carnivores at 12 psi on all corners, does this sound about right? only do trail riding with some rocking areas.

 

What does the sticker say in front of the steering wheel this is the sticker on my 2015 suggesting don’t exceed speed,
Plus you got bigger tires that takes up some power.

 

Thanks for pointing me in that direction. Mine says 68mph. Not getting anywhere near that right now. Maybe the tires are too big and causing the power drag....

 

Could be the spider nut backed off

 

My xp4 900 ran 70mph about 8300 rpm if I remember correctly with stock tires
Did the 40 mph just start happening or when you put the larger tires on?
30 seconds won't let you get top speed but it would give us a better idea of your speed and rpm

 

I bought it used with the larger tires so I dont have a baseline to reference against the smaller (stock) ones. I'll get some more info/data tonight and see what gives. All of you have been super helpful....thank you!

Current odo readings: 1524 mi, 140.3 hours

 

Questions on OP's behalf and for my own learning.

Stock tire size was/is 27"? Jumping up 3 sizes + tire mass, has to really mess with some overall gearing ratio's.
Stock Clutching? Are they getting through the shift phase or stuck in between, bogging engine RPM down?

OP, was your machine built up to be a crawler, set up for low ranges instead of top speed? Trans gear reduction?

@Crash City SxS would be the guy to ask about transmission gearing in a situation like this.

 

You are correct, the stock tires are 27" and I do have stock clutch. It doesnt seem to get bogged down while I'm crusing around, it handles hills nicely, the RPMs get up pretty quickly, but I dont have anything else to compare it to.

 

Check clutches for wear of the rollers and wear on the helix and the driven clutch

 

Your speedometer is going to be approximately 10% off so you need to add 10% to whatever it reads.
Thirty seconds at wo throttle should be enough time to determine your rpm close enough to know if you have a clutch problem.

 

Ok. I’ll get a video of it (RPMs, speedometer) and see what y’all think. Appreciate the help!

 

Can of worms here…my personal opinion…assume your clutch was good and oem and trans had oem gearing I don’t think your belt would be very happy and you wouldn’t be stating that it feels good.

For certain you should still be able to go faster. If the belt was slipping that bad to not let it get past 40 you would smell it for sure.

A big tire helix in the clucth won’t cut your speed and the taller tires will actually slowly add top speed.

I would think if your spider nut had backed off or buttons on the secondary causing problems you would be slipping the belt like crazy and/or have more problems. Could be wrong.

I would check your gear ratio…put it in high jacked up. Make a mark on your secondary and inner cv on the axle and by hand turn the secondary to see how many revolutions it takes the sec clutch to make 1 revolution of the axle. Best way I could think of to check

Idk if this correct or not but all I could find for rzr 900 4

Polaris 2016 RZR 900 - Manual (Page 135)

Polaris 2016 RZR 900 User Manual • Specifications, Clutching, Output gear ratios • Polaris Cars

www.manualsdir.com

 

Here’s what I got

 

That doesn't sound bad at all. Better than 40 mph.
Was it the speedo or gps that you recorded speed?
The larger tires will show your speedo read slower

 

I used speedo. Here are pics of primary and secondary. Not sure what I need to look for but I don’t see anything that looks out of place.

now On to finding paddles for glamis. Looking at SS360 28x10x14 Fronts and 28x12x14 rears vs 30s

 

Not sure what you want to look for
61 mph in 30 seconds with a 900 and over sized tires at 8000 rpm?
I bet gps speed is even higher
Your 900 is faster than my 1000 with stock tires
If it was 40 mph then yes you need to look for something

 

Roger that. I had it opened up so I snapped a couple of pics. Have a great riding season!!

 

For one thing, get rid of the square pucks and put round ones in. 2nd, check the drive clutch helix for wear where the weights are.