Quote:
| Originally Posted by andyb You dont really change a shim. They are nothing more than round discs that sit between opening and closing rockers and every valve, both inlet and exhaust.
They are made in different thicknesses and are fitted to achieve a valve clearance. A variety of things wearing or not, can affect the clearance, not least of all them not being right from day one!
So you would first measure the clearance you have on each valve. compare that to what the gap should be, then either add a thicker or thinner shim to replace the existing one, to achieve the corrected gap................
Does that help? |
Kinda like.......... changing a shim
I am interested to know if generally the testastretta heads require less frequent valve shim changes than the 9xx/748 series.
It has been suggested to me, by a dealer, that it is not really necessary to even check them until about 12000 miles on the 749/999 series. Also, on the older series I thougt it tended to be the vertical exhaust shims that required changing first. Is it the same with the new heads?
Could be that bike mad is the only to have shims changed as early as 6000??