From Thumpertalk.com - 10-26-2013
Once the valves initially sink into the head they keep going because the coating on the valves goes and the valve keeps moving. I suggest new valves. If you want long lasting valves go for the kibblewhite intake conversion kit that comes with the springs. i reckon its the best option. as for the head its self, most of the time you shouldn't need to touch the seats because there usually fine, if they have gouges out of it or is very worn you should send it out, but the seats are usually good because the seats are harder than the valves in these models.
From Motosport.com - 10-13-2013
These valves were perfect in my 2010 kx250f, they seated good and the springs and every other aspect of the valve kit went in my motor great! definitely recommend these valves and motosport for any engine parts!
From Thumpertalk.com - 09-23-2013
We have a 2002. The main thing is that they eat up the stock valves. We went with the kibblewhite setup and haven't moved since. If you do go that route make sure to get the kibblewhite springs cause you sure don’t want to float a valve.
From Rockymountainatmc.com - 08-08-2013
Good Price and Perfect Fit
From Motosport.com - 07-13-2013
Best valves you can buy! Fit is great and quality that is second to none.
From Rockymountainatmc.com- 07-10-2013
Swapped right out with the stock valves. Sealed up good and tight against the valve seats.
From Kibblewhite's Facebook Wall- 05-11-2013
IHorsepower in a box showed up this week. A refreshed head for M3 Racing Factory Honda CRF450 AMA Pro Singles machine, work by magic-man, Mike Perry. Thanks KPMI
From Motorcycle-superstore.com -05-02-2013
Good Quality. Fitment Issues.
This kit comes with everything you need but unfortunately came with the wrong size valve seals. Note, the bike I bought this for is a 2004 Honda CRF250x. Anyway, after some time on the phone new valve seals were shipped to me next day from Vance & Hines who actually puts the kit together. The valves and springs are made by Fraction MX so the quality is superb. Anyway, I still recommend this product for the build quality.
From Rockymountainatmc.com - 04-01-2013
What can I say? They're Kibblewhite. Great brand, great product.
From Motosport.com - 02-27-2013
Fantastic product! Quality looked amazing out of the box and brought them along with my head to local shop to have seats cut and kit installed. Hour later I was home bolting everything back into specs and my bike roared back into life. Incredibly pleased with the product and my bike feels incredible with this intake kit installed. Can’t wait to get back where I belong!