rechambered head and ignition timming

[Tommyz125]

The head on my stock airsall cylinder+piston ( higher compression than stuck jug) 155 psi and a good squish gap 0.80mm. The engine pull good but it Ping at high rpm, do you think retarding the ignition Will resolve That? I run 94 pump gaz cause 87 do preignition. Whit your bike with modified Head do You have to retard the timming?

 

[Larry's Shee]

Try backing timing to zero. Have you done a plug chop? You may be lean also (pinging) .

 

[blasterbrian]

Stock timing? im getting my head done now by ken o connor? And run 94 as well

 

[Larry's Shee]

Well , see what Ken suggests then.

 

[OConnor Racing]

94 is fine with my head mod. As Larry stated, check jetting. This cold weather raises hell with these engines.

 

[blasterbrian]

Thanks ken, i wont be starting my bike until the weather gets better, we just got alot of snow the past few days

 

[blasterbrian]

Is the stock timing good or does it need to be advanced or retard?

 

[Larry's Shee]

Should have asked is this a recent development, or always been this way? What was the temperature when you last ran it ? Temps now?

When you get head on list your other mods, size of carb, Jets in carb, and temperature. We'll try to get it closer.

 

[Blaaster]

Is the stock timing good or does it need to be advanced or retard?

I find that stock timing seems to favour the re chamber mod...