During the last half of last season my Blue 02 Viper started to give me a hard time ,every 500 miles or so the hot plug or the clutch side would start to foul up,I cleaned the carbs,checked the compression,and changed the coil on the cylinder,still the same,cleaned out the fuel pump,my last step as I thought was an engine rebuild. My very youge friend that races motorcycles came to my rescue. It was the reed valve,when I told him that when I took off the air box in the spring it had an 1/4 inch of gas in it.No back preasure in the compression stroke,very common problem in the Yamaha reed value.He told me that if you get 3500 miles on a set you should change the reed only as it will crack and chip if the motors power valves are not cleaned on a regular time frame at least 2 times a season. It pays to keep your Viper Clean He also told me to run a little injector cleaner at least 2 times a season also. Does any one know if a high quality cleaner will harm our baby,s 
Millinocket Rocket
New member
How many miles on it?
Concept Carbon
New member
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