My xj650 fouling plugs?

Hello everyone, I recently purchased an 82 xj650 that had not been run in a couple years the battery was bad and the guy said the carbs needed to be cleaned, so i took it to a mech to look at it and to my surprise was told it would 900 to fix it...
1.New plugs BP7ES 4
2.Oil filter
3.Intake boots 4
4.Carb kits 4
5.Battery
6.Slow Jet?<--
Any way i got it back took it for a ride and it was good but over the next couple days it fouled out and died. Thinking i flooded her i just pulled the plugs and they were black<-- so i bought new ones and she fired right up took a 30 minute ride and it seemed like it was starving abit so i brought it home and now it back fires and i need to have it wide open to keep it running.. Sorry for long post...

 

Ouch, sounds like your "mech" doesn't really know what he's doing... almost sounds like the choke is being held open.

Make sure that it fully closes (the little fingers RELEASE off the plungers when it's off. Take a close look at all 4 while you operate the choke control. You should see all four sets of fingers engage the plungers at the SAME time.

Floats could be set WAY too high as well, and your carbs are just dumping gas into the cylinders. There are multiple guides/advice on how to check this and many other things, search is your friend

Welcome to the board too!

K

 

Running rich is what sounds like to me.