Hello

I have a uforce 500 utv the problem i'm having is that i have a hard time starting it when left over night and after sitting for an hour or so. It will run all day with no problems and start up just fine. After about an hour after it as been sitting it will be  hard to start again. Anyone know what is causing this problem any help would be a great help thanks.

 I had the same problem. I'm assuming you are fuel injection, not carb..
I took the fuel pressure regulator apart and the small o-ring had split. Put a new regulator in and, much better. Still overnight I will cycle the key at least twice, sometimes three times before I try cranking it. Starts pretty good then.

First, I assume you are turning the key on and letting the electronic fuel pump turn off before you try to start the machine, right?  If you are doing that, my next question would be, are you using the correct gas recommended for your machine?  Believe it or not, but using higher octane rated gas doesn't ignite as well as a lower octane.  Enjoy the hunt.

Checked o rings no splits in them and been using same gas since i had the bike. The only way i can start it now is with quick start, do you think its my throttle position sensor causing all of this and do you know a place i can get the sensor without buying the throttle body. Thanks

Problem found intake valves clearance out of specs.

Awesome. 👍 thanks for the follow up.

[2015 Z Force 800 53/Trail EPS]

Yes...thank you for the follow-up.