Sudden loss of compression
Posted October 13, 2004 - 02:06 PM
Posted October 13, 2004 - 08:10 PM
Posted October 15, 2004 - 11:02 AM
Since your bike was running fine before you shut it down it may be a sticky valve, although a 10 minute shutdown doesn't give it much time to rust.
Posted October 16, 2004 - 08:43 AM
My 98 WR did the same thing. Revving high at shut down and no compression when I went to start it up again. Started taking it apart and looked into the carb to find there was part of the slide plate missing. There is only one direction those broken parts go and that is into the engine. Pulled the head and found several pieces of the plate laying on top of the piston. The problem that caused the lack of compression was that one small piece had become stuck between the valve and valve seat causing an open valve all the time. Luckily there was no damage to anything else other than the carb but still very costly at $170 Cdn for the plate and seal.
Check the slide then the head and cylinder.