I recently installed a performance single carb kit on my 07 spirit c2 750. My main jet plugged up on me while riding so while I had it apart decided to fix my issue of being lean(afterfire on decel) from aftermarket exhaust and intake that was put on previous to me.
I had also seen in videos plugging the vacuum ports for an added performance benefit. I added all the parts and plugged the ports but when I tried tuning the bike (went through all 5 jets that came in kit and used air fuel screw for tuning on each) I would still get afterfire out of the exhaust. Didn't matter if it was a 1/4 throttle rev or full. As soon as I put the vacuum system back and decided to start at the smallest jet again (142) the afterfire completely went away with hardly any tuning. I'm just curious if the vacuum delete "hack" is inapplicable to my bike, do I have to eliminate the vacuum petcock for it to work, or did I go wrong somewhere?
Just an fyi when I disconnected the vacuum line I plugged the 2 carburetor ports and removed the hose and plugged the port where the hose was connected. Not a mechanic just doing my best😂
Bike ran way better with the new jets and put 1200km on the next weekend on a trip. Just need to get used to the new fuel economy hahah. Thanks
