mattl31
02-01-2011, 07:08 PM
Hey guys,
I have my 00' 400ex torn down for what I thought was going to be a simple valve seal replacement, however I have a few questions that have popped up.
This all started with it burning a touch of oil upon startup, but only after it sits for a while. Valve seals seemed like the logical choice being that the motor was rebuilt just a year ago, however I measured the piston to cylinder clearance and its seems out of spec. The motor is just a 11:1 Wiseco piston, stock bore (once over i believe). Top of piston looks clean, cylinder walls arent scored, but for some reason seem too shiny to me as I can hardly see any honing marks.
The largest measurements I'm getting are .005" and .008" (on opposite sides of the piston. This means .00625" clearance on each side if centered. My service manual states that the service limit is .004"
Is my logic correct that this thing needs a rebuild or am I missing something?
I have my 00' 400ex torn down for what I thought was going to be a simple valve seal replacement, however I have a few questions that have popped up.
This all started with it burning a touch of oil upon startup, but only after it sits for a while. Valve seals seemed like the logical choice being that the motor was rebuilt just a year ago, however I measured the piston to cylinder clearance and its seems out of spec. The motor is just a 11:1 Wiseco piston, stock bore (once over i believe). Top of piston looks clean, cylinder walls arent scored, but for some reason seem too shiny to me as I can hardly see any honing marks.
The largest measurements I'm getting are .005" and .008" (on opposite sides of the piston. This means .00625" clearance on each side if centered. My service manual states that the service limit is .004"
Is my logic correct that this thing needs a rebuild or am I missing something?