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08 450 exc-r valves a tad loose


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I just checked the valves on my 2008 450 exc-r, 100 hours on the bike, every shim was 3mm and all are on the loose end of tolerance

.2032, .1778 on exhaust

.1778 and .1524 on intake

the only one that concerns me is one intake and one exhaust should have a 3.05 shim, as they are just out of spec on the loose side anyone think it's worth changing it? I'm not even sure if ktm or harley make a 3.05 mm shim

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It's odd that everything is loose. Valve lash tends to tighten up over time as the valve recesses into the seat.

Yes, that is what's typical ... the valves tightening up over time ... due to valve face and the valve seat wearing away.

But! I saw some pretty good wear on the rocker arm shafts on my old '08. And if that wears away .. the your valve clearance could "grow."

Which is probably why KTM has superceded the '08 part with the improved '09-'10 rocker are shafts. They're probably made of a harder material.

Hey Megadeath! If you want to run an interesting experiment - swap out your rocker arms shafts with the new superceded shafts - and then recheck your valve clearances. You might just be in spec., eh? :^)

Cheers! E-Ticket

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