yz450- General discussion on learning to work on bikes

Hey guys, I'm hoping that some of you can comment on the whole process of getting into doing bike work yourself, and maybe some things that would help a newb such as myself in learning to do things on their own as opposed to being scammed by dealerships. Even including some basic tools for doing routine maintenance would be beneficial. 


I'll first go ahead and provide some background: I would definitely consider myself a novice dirtbiker all around, both riding and mechanical competence; I had a couple bikes when I was younger (CR85 as a kid and had a RM125 about 7 years ago), but never really rode a ton so I still overall feel pretty new to the sport. I recently bought a used 2010 YZ450f though in order to get back into it. The bike is really clean and runs great as of now (outside of being a total bi*** to start at times), but I don't know a lot about the history of the bike as far as hours and all go. I do know it was raced as a woods bike in a hare scramble series for a couple seasons, and the guy I bought it from seemed to be the type that takes good care of his things and overall pretty well educated on bikes. He told me specifically that the bike had around 60-70 hours on it in total, but theres really no way of knowing for sure. 


Anyways, I'm enjoying the hell out of riding it right now, and I've so far put about 20 hours on it myself, mostly trail riding. I can do basic things like oil changes, filter changes, and I even checked the valve clearances recently after youtubing some videos on how to do it, and as long as I was using the correct "feel" on the feeler gauges they are still in spec. The EFI mapping is kinda dumbed down I believe in order to help out with not being so powerful on the low end (I THINK atleast--> the current map is most similar to the "Less Hit" map by MXA, but not exactly the same). The bike has Dr. D exhaust and silencer. The rear sprocket is also a 48. 


The reason I'm including this info is because the bike seems a little weak in power compared to what I remember about riding a buddy of mine's CR450f back a few years ago. For instance, I can pin it in second or third gear and the bike will not even stand up on it's own if I'm sitting dead centered on the bike. Hell, I can't get the bike to pop up unless I'm in first and popping the clutch actually. The bike is still very fast overall and seems to run just fine, it just seems kinda weak on the low end as far as quick throttle response. I'm not sure if this comes down to the EFI mapping being set the way it is currently set, the 48 sprocket, or if the bike is insidiously losing power from something going on in the motor (from what I've read it could be a number of things including piston/rings or cam chain/timing). 


Regardless, I would like to be able to figure it all out on my own without the help of a dealership. I live in the NE Tennessee region and do not know a single mechanic around here, and I really want to get into this sport with the mindset of being able to do my own bike work. But like I said, I'm fairly new to bikes overall, and the most involved thing I've literally ever done with one of these new four strokes is check valve clearances. Even if nothing is wrong with the bike, it is likely getting on up there in total hours on the engine and will therefore eventually need routine maintenance work done (which I would like to do myself). So, I guess this post is really a two part question: one on whether the bike is actually losing some power or just set up to be a little less aggressive on the low end, and the other on the process of getting into doing bike work yourself without totally F***ing up your bike and being forced to pay major $$ to have a professional salvage your mistakes. Any help/advice would be greatly appreciated. Thanks. 

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