Got a stock evo with a Super E shorty.
At partial throttle I can hear a slight detonation. At full throttle it's quiet and pulls good. idles good. If I retard the timing anymore the bike runs like crap. The plugs are a light tan colour. I suspect that it's running too small of a intermediate jet??
I've read that a stock Evo should have a .295 intermediate jet which is the smallest jet?
Any thoughts?

 

a .295 is not the smallest int jet,but I wouldn't want to put a smaller one in.are you sure its detionation?if its pinging @ low throttle opening,its sure to ping under max load

 

Increased intermediate jet from 31 to 33. Main jet is 66.
Runs better, more responsive. Still hearing slight detonation at partial throttle. No pinging at full throttle.
Driving me nuts

 

are you hearing this a roll on,or steady throttle?if its at a steady throttle,it isn't detionation.BTW, a 33 is too big for a stock 80"er (and actually a 66 main is on the small side)

 

Everything I've read says about a 295 intermediate and a 70 main.
Since I replace the jet to a 33, throttle response seems crisper. Go figure!?
.066 main seems to work too.
The bike is a 72 FLH with a 87 evo running points. (I like points)
If I really retard the timing the "pinging" almost goes away but performance goes down the tubes. If I advance the timing, the motor pulls good but then I hear that friggen rattle.
Whether the motor is totally stock or not I'm not sure.
I bought the motor 5,000 miles ago used to replace a broken shovel.

 

first ide check for a intake leak,that would explain the better respose with the bigger int jet.but it sounds to me like you've got higher compression pistons with a stock (or close to stock) cam

 

I checked for leaks and found none.
I did find the exhaust shields were loose and the cover for the battery was rattling when I hit it. Stuck a chunk of rubber to isolate it. As soon as the rain lets up ill give it a go and see if that was the prob!
I'll let you know.
Thanks!