Do any of you wrench heads have any knowlege about the 2001 kodiak 10.5.1 compression 84.5mm/71.5 stroke piston being put into a 2001 big bear (8.6.1 comp 83 mm /71.5 stroke)with out hitting the valves.would i be able to bore to the bigger size of the kodiak and increase power?They have the same stroke. There is no higher compression piston made for the big bear that i could find and i really want to beef up the big bear.

 

Hello...I was just looking through my Wiseco book and the stock piston for a Big Bear is 83mm and according to the book the stroke is 64.5mm...my book is the 2000 addition so I'm not sure if they changed the stroke in this years model of the Big Bear...I biggest piston they list in the 10.25:1 comp ratio is 84mm or .040 over size. The Kodiak has the same size bore as the Big Bear 83mm but the stroke is different in the Kodiak 71.5mm the part numbers for both pistons are different also...Give Wiseco a call at there tech number in Ontario, Canada...(519) 537-6281...I'm sure they will be able to help you out...or try there web site...www.wiseco.com/
BB

 

Hey thanks for that info, im a little confused on 2000 specs, i have not been able to find any,i know the 2000 kodiak is a 8.6.1 comp and in 2001 they changed to a 10.5.1.but the yamaha web site gives a stroke of 71.5 on both .Not an easy one to firgure out with the info thats out there.