I adjusted the valves on my 01 raptor and the exhaust valves were loose but the intake valves were way tight. The only thing I can think of is that the valve seats wear down, allowing the valves to sit higher when closed decreaseing the valve clearence.Any thoughts?

 

If this is the first time you adjusted them, they could have been set tight from the factory. When I adjusted my '02, all 3 intake valves and 1 exhaust valve were tight. One exhaust valve was spot on. This was with about 20 hours on the machine and I did ride it easy to allow it to break in properly. I seriously doubt that there was any wear on the valve seats to cause this.

 

Yep, tight intake valves in pretty much the norm. Generally, the exhaust valves are correct from the factory.

/Jon

 

Yes..that is a common misconception with valve adjustments. Most people assume that when a machine is ready for adjusting, the valves are loose.
When in reality, they tighten.
Of course there can be other problems causing the valves to loosen. But for the most part, the gap decreases.

 

Absolutely, valves can go either way, that's why they need regular manual adjustments. On automotive motors that's generally handled hydraulicly, but there are plenty of exceptions there too. Another note is I've found and heard of valves being a little on the snug side from the factory, I suppose this is to make the motor quieter for test drives ect.

 

Like I have posted several times now, the intake valves on the Raptor tend to tighten quickly. The exhaust valves tend to stay in tolerance. If you check them about every 20 to 30 hours they will be tight and will need to be adjusted. I don't think the manual states that often but it is better to be safe than sorry.

 

do you check valve clearance with the engine hot or cold??

 

You should check the clearance with the engine cold.

 

Cold. The best way is to let the bike sit over night, if you rode it that day, and do the adjustment the next day. I usually wait to do all my adjustments, oil changing and greasing, cleaning the filter, during the week after riding on a weekend. The most important part to the adjustment is finding the TDC of the piston. Remove the covers on the side of the case and spark plug and align the mark on the flywheel with the mark on the case. There are a couple of marks on the fly wheel like and "H" so don't use that. After you have aligned the flywheel check your valve spacings. The easiest way to tell if it is TDC is the exhaust valves will be open and the intakes will be open. If they are not all open then you will need to turn the motor at least one more time.