I've had 4 of them starting in 2010. They are bulletproof. The suspension is good stock for like 170-190 lbs. Slow down rebound in back, stiffen up suspension on front.
Engine tuner is a handy tool. 2010-11 had more power than the 12-13. I have shorter stock pipes from 2010 on my bikes that I picked up for $50 on ebay brand new. Larger diameter hole in 2010-2011 exhaust. I tired a full Yosh pipe for 1/2 hour. I didn't like it. I thought the bike had a harder hit in the powerband with a softer lowend. Like too much. But that is me. Hell it makes 55HP, how much do you need? I actually use the tuner to detune the bike, and I ride faster. To each his own. Actually Ratray said they did the same thing for him at HiPoint, and well, he did pretty damn good with less power.....
Now the steering part. First of all, I think the turning issue is a throttle control issue. If you chug-a-lug it, like lots of slower b riders and seniors, the on/off nature of the powerband really, really upsets the balance of the bike. On/off situations with the throttle makes it not steer real well. If you have ridden this bike in the pits , you know what I am talking about. It is a on/off thing that is pretty herky-jerkey. Same thing happens out on the track if you are not smooth with the throttle. Millsaps did not use the engine relocation kit. He didn't like it. He did use factory linkage, which did much the same thing as shortening the shock. But it was a little different. I talked to JGR in the pits at Budds last year about this .
The back end is about the most hooked- up rear end I have ridden, although I have not ridden a 2012 or 2013 Kawi 450 or a 2013 Honda.
I have the Dr D radiator lowering kits on my bikes. I don't think I feel any difference, but have them from bikes in 2009, so I use them.
Shorten the shock 2mm, or run 110mm of sag. I ride mostly rutted tracks here in Eastern Pa, so those tracks that run quads, that may not work with shiny smooth corners. We don't run quads at the two series I attend. 110 makes the bike super stable on the entrance into sweepers and rutted straights, like at a national.
I can tell you what the shorter shock does, as I can give you a link to it on Thumpertalk I wrote up. Let me know and I will post.
I run all stock Yamaha motors with 2010 exhaust. I do OK in the +35 through +50 classes. Bike isn't lacking for power. As a matter of fact, the guys that own PR2 engine works in Quarrytown ask me how I liked my 2010 in 2010, as that bike at the time had the best numbers for a MX bike that they ever seen.
I do have some connections with Ohlins, and I do race with that stuff. The real TTX stuff that is very pricey It really makes the bike turn like a Suzuki without headshake. It is not worth the money for the benefit you get. Oh, it makes it better, but only when really pushed HARD. Like maybe 1 second a lap? Hell, training will get you more than that for nothing but your time.
One last thing. JS7 won more last year on a Yamaha than he did with a Suzuki. Millsaps finished the same, but he did ride better. But Yogi helped out in that. Anyhow, Nico Izzi did better on that bike than the Suzuki this year. Kinary loves the bike and so does Nicoletti.
The bashing started because a Frenchman named Purcell deemed it unridable. All hell broke loose. That's why JS7 isn't winning. Hell, before JS7 broke his hand in 2010, he won his first try on it at A1.
Anyhow, ride the bike It is very good. Just Mathis and a coupe of others hated it or something and did this to the bike. Now they are selling for 5600 new because nobody bought them. Good for you guys then.
I am in line for a 2014 towards the end of the month. Probably get rid of my 2010, 2011 , and 2012 bikes. Not sure what I am going to do with my second set of Ohlins suspension though. Looks like the fork lugs need ( 2014 has larger axle) to be changed and a different top to the shock, but Ohlins hasn't received stuff for this bike yet, so one set might be for sale if it cannot be converted.
Hope this helps...
