I did a bunch of testing this weekend on the 250/300 rods. Went through a bunch of them. My bike was running very good (much better than stock) with the 3-1 we ship with but felt for my riding style (lugging a lot on technical trails) and temps (mild) the 3-1 rod might be slightly lean. Like I said my bike ran great but seemed like it should have more pull and felt semi lean. I tried a bunch of different rods and settled on the 3-2. This adds more bottom and mid fuel and ends up the same on top. This for me and my bike added a good bit of torque / pulling power. I still need to adjust it as I am slightly rich now but I am nit picking. It for sure has more bottom end power, nice mid and same top. Feels like I put a high comp piston or went from a 250 to a 300 type thing. Just more meaty pull. For guys in hotter temps or wanting better MPG the 3-1 is probably the right rod. For trail luggers in milder temps you might want to give the 3-2 rod a try. These are readily available from Lectron or if there is a lot of interest I'll stock them and sell them at my cost to get them to my customers. I feel this is a noticeable improvement on an already good running setup. If you feel your bike does not pull as hard as it should or feels slightly lean it might be worth a go. I really liked the added pull down low and into the mid and felt it pulled a good bit better up big hills and coming out of corners a gear high. Kinda gives the sensation of more cc's. Thanks Kelly Mz