Hi was hoping some evo guys can help did my motor screaming eagle heads,Pistons 10.5 to 1 didnt go over size on the pistons EV57 cam screaming eagle coil and module.Bike runs great but get slight pinging when giving lots of trottle some guys are telling me to adjust my voes.Would you evo experts agree?I have been reading were people say that high compression motors the stock voes might need to be adjusted to get rid of pinging

 

If its pinging you might want to lower your voes setting. Its worth a try.

 

Set the VOES to 7mm hg and the pinging should go away if not re-post and we can see what we can do. Hope this helps.

 

And start using Chevron fuel!
Hatch.

 

Always try to get your fuel at a station that has three hoses at each pump, one for each grade fuel. This is because the hose and pump are full of whatever the last person pumped (usually regular). So if you get three gallons of fuel the first one is regular and the rest may be high test. Hope this helps.

 

would the voes be like the vacuum advance on a car?
with the higher compression, can you limit the advance?

 

The screaming eagle modules are known for bringing the advance in rather quickly and can have a tendency to ping. This can be compounded by heavier bike/rider combo and higher gearing. Plus you have the 10.5 pistons which can be borderline with todays fuel.

 

10.5 with Screamin eagle heads can be a battle, the EV57 is letting some air out of it to help. Need to know where your afr's are when the detonation is occuring, could be lean when rattling or a simple timing retard or voes adjustment needed. Programmable ignitons are nice to have when tuning high compression, you are splitting hairs with that compression between performance and detonation but checking fuel is first to prevent future problems, I've walked in your shoes.

 

Works the same by manifold vacume, it pulls timing when manifold vacume is less but you want full advance for performance when in the upper rpm giddy up area