Anyone that owns an Evo knows it has some upper end valve issues and funky noises. There's lifter issue and a Moco bulliten, there's the inner INA cam bearing issue, (Timken replacement is suggested) and there's the dreaded cam "whine" that progresses to tell you it's going south.
I've been plagues with the "Ticky-Lifter" syndrome, specifically the front exhaust lifter, as expected.
Today, I yanked the lifter screen, and sure enough, it was spotless, as expected, since i maintain the bike well. It has 30,400 miles on it, ridden easy and I use straight 50wt in temps above 50*, and 20-50 below that.
I reinstalled new exhaust gaskets to eliminate that noise ability, then drove the bike 10 miles to go get coffee. Same lifter noises, same highway noises......
Stopped at Napa, and bought a 16oz can of Seafoam. Placed 5 onces (1 oz per gallon) in the gas tank, and 4.5 onces (1.5 per qt) in the oil.
Took the same 10 mile highway (55-70 mph) ride.
FOR THE RECORD
I'm NOT a believer in magical-mystical goopy-cans of shit you pour in your tank/oil and it rebuilds the engine, but I still can't get over the lack of sound, and the change in the engine. Enough, that I took it out and rode another 10 miles, WANTING to hear noise, and nadda......
No noises. 75% less ticky. No NOTHING, than the usual valvtrain noise in the rockers, and very mild cam whine. It was the quietest I've heard the engine since I've owned the bike....ever.
I attribute some of it to plain, old top end lubrication assistance, refering to 10% ethanol use and some of the nasty things it can do, like drop mpg....:
Consumer Reports has issued manufacture warnings regarding damanging effects of E10 10% ethanol fuel on engines including Harley Davidson. Damaging effects include corrosion of metal and non metalic parts in engines, including oxygen sensor damage, piston ring sticking and piston bore failure due to the costic effects of running E10 alcohol gasoline. The report suggest frequent oil changes and to follow manufactures recommended maintenance schedules.