yfz 450

[yfz450-05]

i just got a yfz 450 and it went though the compression test and it came back as 155 is that good or bad? how could i change it if its bad? or what should i do thank you:)

[oxidized_black]

i dont think youre getting an accurate measurement, only because of the decompression valve. a leak down test is way more accurate ,,, Building and Using a Cylinder Leakdown Tester

[marioweldinginc]

d/l an owners manual and read up on the factory procedure. A leakdown test would give you a more accurate story about your internals. It will tell you weather its a piston ring or valves. 155 doesnt sound low to me but Im going by what passenger cars read. In a nutshell you would need to remove the cams and head and inspect valves. if ok then remove the cylinder and inspect the piston/rings.