9801srx
Member
had the blade break off a valve this weekend and need to cut another one,wondering what piston to valve clearence you set them up at so i can cut a new one and check the other two to make sure they are not geting to close.thanks neil.
neil ...i would look to make sure the stoppers in the cylinder are not wore out ...they are what keep the valve from dropping on the cylinder ...
9801srx
Member
thanks for the reply, i know the stoppers on both the clys and valves are worn this is why i need to know what the recomended piston to closed valve clearence is.you can bring the clearence back by milling the surface of the valve that runs paralell to the piston, these valves are in my 780 so i know i have to cut this surface back aprox 2mm to make up for the extra bore size but would be great to know the recomended clearence so i can cut it just right and also to check the other two so i know they are not getting to close. probally good info for all of us with high mileage clyinders and valves,i've seena couple of posts here lately of people with the blade broke off the valve and i'm thinking it could be the valve comming in to slight conntact with the rings which in imo would cause the valve to vibrate bad enuf to break.
.025-.030"
Mac
Member
I have had that scenario where my rings were cutting the power valve. Not by much but they were defiantly rubbing on the corners of the power valve. I just kiss the areas of the valve on my belt sander to provide clearance. You should even rock the valve side to side (valve to cylinder is sloppy) to ensure their is enough clearance. And just think their are many who believe the coating on the valve is important. I think we have all read those threads. I have sanded my valves for clearance several times over 9000 miles. No sign of heat related problems on the leading edge of my valves.
9801srx
Member
thanks ,i knew doo's spec was .030 but never seen a yami spec for this.