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2007 450 EXC valves at 170 hrs

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I bought a used 2007 exc with 150 hours. Bike was very clean, only used for dual sport. It has always been easy to start, hot or cold so I put off the valve check until now at 173 hours (4300 miles). Intake clearance was too tight for even .002" to go in. Exhaust valve clearances were perfect (0.006")

This is what the intakes look like set at 0.006"

006.jpg

and with one turn out

1turnout.jpg

and 1.5 turns out

15turnsout.jpg

Does it look like it's time for new valves ? When it cools off this Fall, I'm planning on putting some serious miles on this bike.

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I don't know how many threads will show above the locking nut. You need to keep an eye on how many turns are left on the adjusting screw before the swivel foot hits the rocker. Less than one turn and you may damage, or even worse, break, the swivel foot off of the screw. 170 hours is low. I got 285 hrs and approx 6500 miles before doing the top end on mine but by then the valves were seriously recessed into the head. YMMV.

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My feeling is you are fine for at least another 100 hours. The 07 RFS motor should be good for a total of at least 300 hours unless your just beating it. Unless your riding on the street you should have another year to save your pennies for a top end.

If the intake was any tighter it would be hard to start. Adjust it and then go back and check it every 15 hours. Write down your changes so you can see if it is tightening, keep a good log. If it needs adjustments at more frequent intervals then it is time for a valve job and a look at the piston.

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