HarleyTechTalk

225 psi cranking ccp, carbureted, the likely cause flat on the crank not properly oriented. The fix is to locate tdc with a piston stop and use a timing wheel, indicator at the lifter, and determine if the valve events match the timing specification. Based on the findings the timing can be changed by tooth changes and possibly an offset key if needed. Timing would have to be 10+ degrees off to show the results being demonstrated.
I am sure this has happened before not just the one time I experienced this in 2004.

IF, the compression is too much, those pistons have enough wall thickness to dish them, and S&S offers a dished version.
Easy to accurately pull 4-5cc's/more from your pistons inexpensively.

They are now dished -3.5cc, heads 92cc, .037 squish. I verified his gauge is accurate

Quote from: ThumperDeuce on September 22, 2020, 11:24:35 AM
Put a cam in with more overlap and enjoy the ride.

   

If crank is oriented correctly change cams. Add 10* of duration and bike should crank about 210psi

S&S 625 should be a good choice if you have the springs for it

So the cam is a SnS 585 or SE 585?

225 hot ain't that bad, retard the timing.  I run 220 cold cranking compression in a 11.3 to 1 motor.  Runs fine except that the early SnS crank rebuilt by dark horse will eventually go bad. Not DH's fault, more SnS using a 1 1/2 inch crank pin.

S&S 585g. Jims/SE crank. I wrote a custom curve for it, 20deg max at 4500 rpm with a lot of dip in high throttle/map pressure lower rpm areas. Still pinged. No more need to crutch this build, the root cause will be found and fixed.

What plugs you running?

I think the 585 cam is a little short for a 117" ,  i like the woods TW9BG ,  i have a 116" and the cam likes 11 + comp ,  it closes at 50 and longer duration  , it does have a .630 lift so would have to have springs for it ,

Quote from: itsafatboy on September 29, 2020, 02:07:31 PM
I think the 585 cam is a little short for a 117" ,  i like the woods TW9BG ,  i have a 116" and the cam likes 11 + comp ,  it closes at 50 and longer duration  , it does have a .630 lift so would have to have springs for it ,

IIRC the SnS 124lc uses a 585.

This motor has 10.4:1 static compression,  fluid measured, cylinder lengths adjusted both same piston to deck height, .037 squish.

How about just enlarging the combustion chamber by 4-5 cc's. pretty simple to do and it doesn't cost much. no new parts needed.

With a 60 degree ex open cam i would want to fix the problem, would think it's probably way down on power too if it's way advanced from there

Fix the problem,  root cause, thank you.