I think it is time for a change from the Banshee. The new fuel injected YFZ looks pretty interesting. One guy in my group bought a YFZ new several years ago and has yet to open the engine. I have seen a lot of blown up motors online. Only looking to add a pipe/filter/programmer to it.

What is your experience with having to do a top end or valve job?

Mine was 3 years on my YZ450F dirtbike with lots of hard riding and frequent maintainance. I can go alot longer now as I don't ride nearly as much and I split my time between the bike and quad. My valves stayed in adjustment till I had the motor torn down for a top end. The engine really is a very reliable design for such a powerfull output. Longevity will be dependent on air cleaner changes first and oil changes a close second. I changed my oil and cleaned the air filter after every other trip and changed the oil filter after every other oil change. Aside from that, keep putting premium in it and ride the snot out of it.

I had 4 seasons on my yfz 2 of them were hard. I changed my oil and oil filter after every other trip and cleaned my intake every trip. I just finished a rebuild and everything looked fine, it did not "need" to be rebuilt. Changing your oil is the biggest key to these bikes IMO besides proper jetting. (which you dont have to worry about with FI)

Like these guys said maintenance is key. With Ti valves, really watch the service intervals, so stay on top of valve adjusts, oil changes, and filter cleanings. YFZ's have powdered metal seats and any contamination will cause the valves to cup and wear quickly.

One thing to remember about the new 450s, most of them share oil between the engine and the trans/clutch. So clutch wear particulates are in the same oil that lubes all of the internals.. I think hondas have separate trans/engine oils but most all the others need to have the oil changed very often, like every trip, or every 5hrs or so. Plus the high RPM nature of the new 4 strokes will break down an oil pretty fast. Alot of people get lucky, but if you really want one of these bike to last you have to stay on top of the basic maint.

Use a less expensive quality oil like rotella (Wal mart 5qts = $12), and change frequently along with a new filter.

Just remember - filters & oil are a lot cheaper than a rebuild

I ride an '04 YFZ450, changed the oil regularly, cleaned the air filter regularly. Ride it pretty hard and often. That said I never had the valves adjusted (not that I recommend that) and finally had to have my top end rebuilt this year. The Valve shop guys were amazed that it was still running it up to the day I dropped it off to my friend for rebuild. Keeping your air filter clean is seriously important (I know I injested sand and began noticing power loss). All that said my bike went 6 years before being rebuilt...

I race my YFZ. it took two years of extreme hard riding to crack a stock piston. (well over 200 hours) Then I grenaded a second gear (operator error on my part, dont land on the shifter) and had another piston crack (less then 10 hours on a JE high compression piston). The new YFZR fuel injected are the way to go. they Have redesigned the engine and corrected the faults the old yfz had. plus the new R has much better suspenison, bars, seat, which make is so comfortable to ride. no jets to clog when the bike sits thru the seasons. push button start from your banshee and no mixing fuels. 91 octane and your good to go.

My son-in-law builds these engines.. fast ones..

The faster you go, the more often you repair..

(His engines run in the top 5 in superbike)

He does shifter karts too.. again top rank stuff..

Most engines are a lease arrangement, with onsite service..

Canada, Spain, Daytona, Vegas, Mexico city, etc..

The old saying holds true, "How fast do you want to go?"

I'm looking to gas and go at this point. My previous Banshee had a power valve race gas motor. It was fast but a PIA. The price for a stock piston, rings and gaskets for the YFZ is cheaper than I had expected.