2010 300 Cylinder Base Gasket Question

[coopernicus]

We ride starting at 2100 meters up to and over 4300 meters (6500 feet to 13000 feet where the trees cannot grow) so our jetting can get a little "different". I was told by the local old timers when I relocated to here in Colorado that the pilot jet is counterintuitive up here and it appears to be so. The thought is that the lower air density and the corresponding lower velocity requires more surface area to pick up enough fuel. I thought it through and it is feasible. The 2010 owner tried a 38 up to a 52 and the 45 worked the best. As for changing the base gaskets out, I've convinced him to wait it out until a top end was needed and try some more jetting (going from N1EI to N1EJ), changing the gearing slightly to a 49T, and possibly a larger volume power valve cover. I love the way the bike runs and don't notice this problem while I'm riding it but it's his bike and he really wants the motor to be perfect. BTW, the N1 needles seem to work really well up here on the top clip position as the lower air density lessens the "hit"! I do have a 2000 300 with the RB Designs Mods and it makes the bike to "open class" like as you can feel each power pulse. The 2010 is absolutely smooth in comparison so he's not so keen on getting the mod and up here we don't have to worry about mileage as I can get over 80 miles per tank full and certainly don't worry at 70 miles per tank! One of these days I will run it dry and see how far I get! Thanks again for the help!

Eric

[Jakobi]

Here I go again.. Has he tried the N3 series of needles?

[coopernicus]

Yes, his other bike is a 285 kitted 2005 YZ with an N3EJ needle...All of the needles other than the N1's seem to make the motor very smooth...Too smooth for our altitude and weight. He is going to fiddle with a JD Jetting kit soon and the around the yard ride indicates the red needle may work well but last weeks ride was on a good baseline needle that he knew worked.

Eric