Synthetic Or Not?

Should i use Synthetic oil? im not sure but i "think" i read in the manual where is says u shouldnt , could be wrong but also what weight should i use for summer, and how often should i change my oil filter?

[VegasEx'r]

The only time I have heard that you should not use synthetic oil (this is for any internal combustion engine) is if if is brand new, or if it has MANY mile on it. I use synthetic oil, and have no problems. Use a thicker oil in the summer, because the ex likes to run hot anyway. I use 20-50, as it gets hot where I live. I change my oil about every 20 hrs (using the TrailTech computer).

[Leo]

I've been running mobil1 15-50 with nothing but good results (winter + summer) up here in NY.. The quad is stored in a heated basement in the winter though..

As for oil change intervals I used to just guess, I recently put on a trail-tech speedo.. If nothing else it will be great for figuring oil change intervals.. :D

Leo