Please help

I recently bought my 1982 XJ 750, and have finally been able ride it a little now with the weather. It starts great and runs well. However, once she is warmed up she idles around 2500 rpms. I contacted the previous owner and he suggested I try the idle adjustment. Does that sound like the first place I should start? And does anyone know where that may be located? Thanks

 

Now don't take this the wrong way but think about it. You open the throttle, a cable pulls the butterflies open in the carbs. You let the throttle close and something, somewhere stops the butterflies closing too much. Given this is a critical safety requirement (as serious as brakes I would say), it's likely this stop is somewhere near the butterflies, which are inside the carbs.
So, take a look at the carb linkages opening and closing as you open the throttle. Under the set you will see the stop, which has a knob at one end, the other is the bit that stops the butterflies closing fully.
Run the bike to, or at least warm, and back this off, bit by bit until the idle speed is somewhere near spec.
You should sync the carbs once this has been done, but before this you might ask the question when was the valve clearances checked, since this will affect the synch.

 

The idle adjustment knob is under the carbs next to #3 carb , back it out and see if idle drops if it does not you have a vacuum leak . Usually the boots crack and can leak check and make sure the nipple on the boot has a plug in place .

 

Thank you for the responses.

 

It could just be the throttle cable adjustment on the handlebar end also

 

check the cable routing , look at the linkage on carbs there should be a little slack at linkage and throttle grip should move a little before the linkage moves. there is an adjusting setup on cable on grip control.
also you want to lube the cable.

check the cup on top of carbs where throttle cable connects to make sure cable if fully seated in the cup.

the idle is between the carbs 2 and 3 at rear of carbs , idle wants to be set when bike is warmed up 10 or 15 miles. set to 1100rpm.

check the choke cable and lube it too. make sure the plungers that are connected to choke linkage are fully seated down when choke is shut off.

are you running a stock paper filter?

if these things do not work for you it will be time to look for vacuum leaks.