4age dellorto jetting

ChagoRacing
Posts: 3
Joined: Wed Jun 12, 2013 6:37 pm

4age dellorto jetting

Postby ChagoRacing » Wed Jun 12, 2013 7:06 pm

ive got a rebuilt 4age 16v with some dellorto dhla 40's (all stock) that i cant seem to set right.
Specs:
Dellorto Dhla 40 H
idle jet- 45
Air Corr- 180
E-tubes- 7772.11
Main jet- 140
Chokes- 32mm
Pump jet- 40
Aux Ven-7848.3

Now i can get it to start but it idles rough as if i have cams installed but i dont. i got it to idle a little better when i have the idle mix screws out 6 full turns so i know it isnt right. it starts popping at high revs. ive set the fuel pressure at 2.5. I have also read that these carbs come equipped with a idle jet holder that wont work is this true??

Any suggestion welcome i need to get this running soon THANX.

ChagoRacing
Posts: 3
Joined: Wed Jun 12, 2013 6:37 pm

Re: 4age dellorto jetting

Postby ChagoRacing » Thu Jun 13, 2013 4:19 pm

anyone???

allencr
Club4AG Expert
Posts: 401
Joined: Thu Jan 10, 2013 9:59 pm

Re: 4age dellorto jetting

Postby allencr » Fri Jun 14, 2013 9:21 am

Before blaming the carb and/or changing jets, everyone has to be very sure that it isn't something else.
What's the compression? Ignition and cam timing OK?
NO AIR LEAKS!!!!
Carbs syncronized, front throat to rear throat and front carb to rear carb?
Float levels set? Venturis in right & tight? Throttle working smoothly & returning solidly to the throttle stop/idle set?

ChagoRacing
Posts: 3
Joined: Wed Jun 12, 2013 6:37 pm

Re: 4age dellorto jetting

Postby ChagoRacing » Fri Jun 14, 2013 5:23 pm

ive check for leaks, timing is right, and i have rebuilt them back to specs i took my time with it i just cant find the right jetting and i dont want to waste money on jets that wont work for me.

allencr
Club4AG Expert
Posts: 401
Joined: Thu Jan 10, 2013 9:59 pm

Re: 4age dellorto jetting

Postby allencr » Sat Jun 15, 2013 11:47 pm

Solder & drill.
Don't get jet drills, the numbered bits are at any decent auto or tool supply.