30mm oko to 34PJ jetting question

[sangheraent]

Alright I had 30mm oko carbs in my bike and I had 150 psi compression with 21cc domes. My bike is around 65-70 hp

 

Now I have 34pjs with about 180psi compression everything else is the same 19cc domes

 

my 30mm jetting was 162 main and 50 pilot middle needle clip bike ran great. How does jetting translate with bigger carbs. Is it 4 mm bigger so Im going up 2 sizes or somthing I donno im just guessing.

[sleeper06]

You can start there an work down unless your heavily ported you shouldnt need to go up

[armyvet]

i would start down 2 sizes.a bigger carb isnt going to see as strrong as a "signal" from the motor due to the simple fact theres going to be less velocity.So less air flow means smaller mains.thats just a condensed explanation.

[sangheraent]

So less air flow means smaller mains.thats just a condensed explanation.

thats exactly what I wanted to hear. thanks.

[sleeper06]

i was giving you the safe route,I have tuned many bikes,you allready are running 162 with the lower compression and smaller carb,now your adding compression ,race gas which jets diffrent depending what kind and bigger carbs added too,compression is power but your no newb so you know

[252wheelieking]

thats exactly what I wanted to hear. thanks.

 

I run 34PJ's & im dailed in at 48 pilots mid clip & 158 mains (summer) 50 pilots mid clip & 162 (winter) at sea level. Hope this help you out.

Edited March 8, 2011 by 252wheelieking