short backstory (all i have to go on)

1988 883 with 1200 kit and true dual straights

yeah thats it...just finished rebuilding and cleaning the carb, changed oil, filter, plugs, wires and primary fluid

ok so,
1- how do i know it was properly jetted for a 1200 with straights (ie what jet i should i run with straights and a CV carb)

2- the plugs that are in right now are the ones the service manual says to use (6R12) for the 883, should i be using plugs for a 1200? are they firing too hot, not hot enough etc...after replacing the plugs, the rear cylinder constantly fouls, i clean the plug and it works again (black carbon deposits)

and

3-what would be the proper setting for the mix? i was told to bottom out the mix screw and turn back 2.5 turns and go from there


my buddy revved the f out of it after some adjustments and it was backfiring on acceleration and he said its dumping too much fuel, hopefully the rebuild fixes that...uh HELP lol tia

 

A good starting point for a 1200 will be a 45/180 combo.

You can stay with the same plugs and be fine. Carbon deposits indicate you're too rich or running with the choke out.

Anywhere from 1.5-3.5 turns on the mixture screw is ideal. Most people tend to settle in at around 2-3 turns depending on location and bike. Setting it at 2.5 is a really good starting point.

 

It is interesting you said your front cylinder runs leaner than the rear, my bike has always had a tendency to do that. Anybody know what will cause this? I have replaced all the intake seals and tested for leaks.

 

Is your accelerator pump spraying at the needle? Or possibly to one side or other of carb throat?

John

 

At the needle.