tickover problems with xj600n

[Guest]

I have a 1999 yamaha xj600n, and in the last couple of days once the engine is hot, the revs dont come down quick enough. I could rev the bike to 300rpm and it will go down to around 2k, then slowly down to about 1.3k or 1.2k. Also, at the traffic lights earlier today the revs were at 2k. When engine is cold, everything is fine. Help. I dont know what to do and cannot afford taking my bike in for a service just yet. Thanks.