Bike sat for approx 3 years, put new fuel filter in tank new plugs new oil and new filter, bike ran great for about 20 minutes. bike then began to sputter and hesitate. added fuel injector cleaner and high test gas, pulled plugs cleaned them and reinstalled. how can i get the carbon and gunk build up i see on the valves off without complete teardown. HELP ME

 

When an engine sits for an extended period of time, moisture will find its way into the engine and can create serious damage, especially around piston rings, cylinder walls, and valve seats. The best way to combat it is to lube up the cylinder walls with oil by taking out the spark plugs, dropping some in, and rotating the engine by hand.

Do you know if that was done prior to storage?

 

I seriously doubt it the previous owner was a dumb a$$. i noticed a lot of carbon built up on the valves looking down the intake. trying the additive measure first to see if i can break it up and blow it out.
i flushedengine with honda general oiland reinstalled HP4 and new filter.
Bike ran like a raped ape at first after first go around. then just fell on its face later. i have been reading about the FPR, do you think it may be clogged or is that possible. thanks for any help