FJ1200 ABS 1991

[poisondwarf]

Hi everyone,
Having a problem with my new FJ12 1991 abs model. I have read some of the comments that are similar to my problem on here.
But none seem to be the same as advise given is for different models of FJ 12's.
i am getting a backfire from the right exhaust when you try and rev her up.
So done the logicals and tried to test spark and seems ok changed out the plugs and air filter with no difference.
reset and balanced the carbs no difference but since this has been happening the plugs look like she is running very rich on all cylinders.
Now i am not familiar with carb work bar basic setting and balancing.
I do understand that you ballance 1&2 then 3&4  as  pairs then bring them together with 2&3 carbs.
The fuel pump is doing as it should and the fuel filter under the tank is free flowing.
Can anyone help advise what this may be please.
Missing being on the road with her 

[FJ_Hooligan]

Is the backfire a loud bang or just a popping noise?

If it's just a popping noise then you probably have one or more dirty idle circuits in your carbs.  Next time it's running, after about 2 minutes spray a little bit of water on the header pipes and see if one is cold or not as hot as the others.  This will tell you which cylinder(s) or carb(s) are suspect.

Did the bike sit for an extended period of time recently?

[poisondwarf]

Hi,
Thank you for the reply, the head is running even temp.
i have a laser thermometer thingy & its running within a few degrees across the head and cylinders.
It is not a loud back fire it is like a loud popping and it is not with any regularity either.
Same with the down pipes. But it is more prominent through the two right cylinders.
I have a friend that has offered to deep clean them with an sonic cleaner for me over the weekend.
So i will let you know if this cures the problem.
Regards Frank