New Bike - Little help

[why walk]

Hi Just bought a 1981 model XS 400. Top nick and a really beautifully looked after bike - its only done 9000 miles but hasn't been been on the road since '91.

I have the odd problem that she starts up fine on choke, and when I take the choke off it ticks over perfect at 1200 rpm.
The difficulty lies when the engine warms up the revs go straight up to 2500 and it wont drop back down.

-Any help?

 

[FlyingAnvil]

Welcome to the good stuff. I had one that did the same and I did a carb clean ( took them apart carefully and used all the same parts because the parts store didn't have any parts or gaskets) and everything worked great afterwards. Good luck and let's see a pic.

 

[why walk]

I have had the carbs out and apart once already, what was blocked with yours?

 

[FlyingAnvil]

Just all gummed up. I didn't find anything in particular just bad fuel. You may have a vacuum leak or may need to reset your idle.