rappin_ernie
04-04-2009, 07:36 PM
Hi everyone,
I recently got a YFZ450 to work on. It starts and runs fine, but it is making a nasty top end noise. Sounds like metal to metal. I pulled the valve cover and checked the timing and chain. I adjusted the timing and tightened the cam chain. Everything looks good, however it was very dry up top, and I think the lubrication system is failing to get oil up top. Once I got it back together, I filled the oil up ( Exterior tank and crank, crankcase was almost dry ) and fired her up. She ran fine but still made the noise. As soon as I rev it up or ride it, oil shoots out of the overflow hose from the little black container up under the plastics on the sub-frame in mass amounts. I think maybe the strainer is clogged and as soon as you gun it to give the oil pump some pressure to get up top, it is backed up and overflows out of the overflow hose. I think the lack of lubrication is making the noise as well. I would check the oil strainer, but from looking at schematics, it looks like you need to crack the cases. Anyone know what is wrong here or what to check before I tear into it? Thank you!
Mike
I recently got a YFZ450 to work on. It starts and runs fine, but it is making a nasty top end noise. Sounds like metal to metal. I pulled the valve cover and checked the timing and chain. I adjusted the timing and tightened the cam chain. Everything looks good, however it was very dry up top, and I think the lubrication system is failing to get oil up top. Once I got it back together, I filled the oil up ( Exterior tank and crank, crankcase was almost dry ) and fired her up. She ran fine but still made the noise. As soon as I rev it up or ride it, oil shoots out of the overflow hose from the little black container up under the plastics on the sub-frame in mass amounts. I think maybe the strainer is clogged and as soon as you gun it to give the oil pump some pressure to get up top, it is backed up and overflows out of the overflow hose. I think the lack of lubrication is making the noise as well. I would check the oil strainer, but from looking at schematics, it looks like you need to crack the cases. Anyone know what is wrong here or what to check before I tear into it? Thank you!
Mike