I was wondering if anyone else has had this problem or know what could be wrong. I have a lcr 225 ive have the cam belt and spark plugs done last week an now I seem to be getting a flat spot at 4500-5k rpm with a speak/whistle? The tubro sounds like its struggling a bit and the exhaust manifold glows really red. If any one has any hints or ideas could you let me know many thanks.