OK now i have 8 hours on the 840 and i just picked my Teryx up last night from a motorcylce shop and they tell mt my head gaskets are good and they are not the cause of overheating. I ride in the Oregon Dunes and now have been out the last 2 weekends and i checked everything including the jetting over and over again and find it is still over heating within 20 minutes of moderate to hard drive time. This only really happens when i have a passenger in the front. It is a 4 seater but never use the rear seat (and yes i am going to remove and do a bed delete to save weight) If i go out and drive hard by myself it last 35 minutes before over heating. I am running Engine Ice coolant and also i have wired a fan switch for me to turn on when the motor is running and i am going to order impeller but what else if possible. I think the impeller onyl works near idel situations but my vehicle doesnt overheat until ran moderately to hard. What is my next step as i want to be comfortable to have my wife go out and drive this without worrying about her overheating it and not knowing to shut down when getting too hot.

What are the temps like this time of the yar in the Oregon dunes, what model is yours.
I think the next step would be upgraded fan.

it is an 08 with a FST 840 and the temp at the dunes have been right at 70-72

FST 840
Dragon Fire Exhaust
Dragon Fire ignition
Clutch Kit

Have you called Mickey, I would call Mickey and see what he suggest and if you still have issues call Steve at dasa 619-840-4485 he has said for a long time that he has had over heating issues on your type set up but I know he puts his impeller in and I am not sure what else but I think he can help you but I would call Mickey first and see what he suggest

Yes i have called Mickey and he suggested the impeller also. I am just wanting to make sure it works, wanted to see if there was anything else needed to make sure i am driving 4 hours to go play and it overheats in 30 minutes, i want my wife to be able to enjoy this with no worries like out bikes and quads.

I have had the same problem with mine I have the same set up as you the only change is that I have a pwr and still have the issue I am also going to order the impeler

did the PWR help out at all. It would be a large expense not to help. I thought the impeller was only really helping out at idle. I know there have been 100's of these kits installed and seems there must be a fix for it and just want to know what it is so i dont have to fart around trying to figure this out. do you think the impeller will help you out? If not what is your next move?

I have the exact same setup as you. I run engine ice a fan overide AND the Hunterworks water pump impellor with spacer plate.. Still overheats after about 30 min of hard to moderate driving. The thing with mine is if I stay WOT throttle it wont go beyond 210 but after a hard run and cruise at low speeds or let idle the temp climbs So I am taking my carbs off tonight and richining up mids to low to about 10.2-11.5 range and see if that works. I will let you know.

I am wondering how the guys who race these in the Baja 500 or 1000 or the many other types of racing do these motors last and not over heat. I wonder what they are doing and is it available to the public. I just didnt want to purchase expensive and none necessary parts to try and correct the issue and everyones feedback is greatly appreciated. by the way 840 made this a very fun vehicle to drive and spanks the RZR'S with ease

Guys I have a friend that was having a temp issue on his FST840 and he added the Dasa impeller and it made a difference, I think it dropped his about 15 degrees and it was not just at an idle, I am putting a impeller in my motor build but I won't know what mine ran without the impeller but I would deffinitely suggest the impeller.