Speedometer for my YFZ

I am looking at buying a speedometer for my YFZ, it seem interesting to have. Does anyone have any experience with adding a speedometer on a sport quad? I'm wondering how accurate it can be. In addition to the speedometer it has an hour meter which helps out a lot with maintaince schedules. I'm looking at this one.

http://cgi.ebay.com/ebaymotors...QrdZ1QQsspagenameZWDVW

 

I have the trail tech Vapor on my raptor and its pretty accurate. It is nice to have and with the dashboard combo it has a nice clean look. I like the Vapor because it also has a tach.

 

Their accuracy is dependent on the installation. You have to program in your tire rollout (circumfrence) so the computer knows the distance traveled per tire rotation. If you program this perfectly it'll be 100% accurate. I had a trailtech endurance, but I ride in mud a lot, and the mud got into the buttons so it didn't work anymore. I still might get a vapor sometime, I'll just take it off or cover it with plastic if I know i'll be getting muddy.

 

yeah after more research i ordered the vapor.

 

this is a good one too

http://www.rockymountainatv.co...yId=6770#vehicleSelect