Hesitating when giving throttle

[zhack]

Just did an ADA girdled head on my ski. The ski seems to have a slight bog when punching the throttle from an idle. It basically hesitates a bit before going. Just wondering if i need to do any carb adjustments for the high compression. running 35 domes now.

Everyone says that the higher compression gives a better low/throttle response but my response is definitely not better

 

[SRQski]

A bog and a hesitation are two different things. Hesitation indicates lean, bog points to rich.
To my knowledge, increasing compression will not change air/fuel requirements.

First thing you can try is opening the low speed adjusters in 1/8 increments, no more than 1/4 turn. If you have to go past 1/4 turn, your issue is likely somewhere else. If that doesn't help, it's time to go through the fuel system from the tank back and likely do a carb rebuild.
Fuel pickup, fuel vent valve, filter, fuel selector switch, carbs - do yourself a favor and don't skip over anything and use Mikuni kits on the carbs.

Sent from my SM-G960U using Tapatalk

 

[fastgtfairlane]

just changing the head shouldnt affect carb tuning. does it feel like it wants to shut off before taking off or is it more of a burp before taking off? does it sound kinda girggly at all?

if it wants to shut off before accelerating, it sounds lean. possibly a idle screw adjustment. if it blubbers before taking off its most likely rich.

 

[zhack]

just changing the head shouldnt affect carb tuning. does it feel like it wants to shut off before taking off or is it more of a burp before taking off? does it sound kinda girggly at all?

if it wants to shut off before accelerating, it sounds lean. possibly a idle screw adjustment. if it blubbers before taking off its most likely rich.

Ya I wasnt sure if it would or wouldnt. Also, I would call it a choke almost. Like when you hit the gas it almost chokes out and then goes. I guess you could call that wanting to shut off/die. it only does this when you're idling or moving pretty slow and you give it a blast. If I'm going at a decent pace and give it a blast it does not hesitate at all

 

[fastgtfairlane]

im just going to refer you to this thread. it should help answer all of your tuning questions. i just finished up my superjet with lots of changes ranging from larger pump, bigger carbs, and new exhaust chamber. i use this thread to make sure the carbs are dialed. having a tach is totally necessary. i dont have a nice pet tach either im just using one thats made for small engines mainly to check idle and just off idle. the refresh rate unfortunately is too slow to do any kind of max rpm tuning but it definitely works for low speed circuits. http://www.x-h2o.com/index.php?threads/carb-tuning-101-info-from-watcon.58480/

 

[SXIPro]

Is the head the only change you did? Did you happen to also do aftermarket flame arrestors?