How often do the valves need to be adjusted?

I got a new 04' YZ450 back in march. I put about 50hrs on it before I took it in to get its 1st valve adjustment. I thought for sure I had waited too long but the dealer said they were still in specs?

How can you tell if you are in need of an adjustment? Loss of power? Can you hear the difference? :thumbsup:

Loss of power and exccesive noise.

Depends on how you ride and how well you do maintenance. If you spend a long time in the upper RPM range then you're more likely to need adjustments sooner than later. Also if you don't keep your air filter clean and dirt gets by then that can also wreck havoc with the valve seats. If you keep your filter spotless and don't rev it much then you'll probably go a very long time without needing adjustments.

Some common symptoms of overly tight valves are difficult starting, loss of low-end power and eventually loss of power across the board if they get way too tight. If you continue to run with the valves too tight then when they leak it can cause burnt valves and valve seats. The valves tighten up so they do not actually get noisier; if anything they will get quieter as they tighten up.

So in short, just check it on schedule and write down your readings. After some time you will get an idea for how often you need to check/adjust your particular bike.

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