RPM not dropping

My son has an '08 SDR that has developed an issue. After being parked for @4 months, the bike now does not return to idle as rapidly as before. the RPM's hang at @2500 for a few seconds before
returning to idle. An Akra evo header and slip on with the appropriate map was installed less than 1000 miles ago which along with a G2 cured all rideability problems up to this point.Thoughts?

Very common issue on here - problem may have one or more of several causes with solutions ranging from 15min reset through resetting TPS (TuneECU) to replacing throttle body, all of which I have had to do at one time or another - given the standing time, suggest you try reset first...................

sticky throttle cable? maybe it's rusted somewhere...

yep my 08 sdr does it sometimes - hangs onto about 2-3k fora bit - makes it tricky sometimes - I did a reset and it cured it - then it returned later on - im going to do reset again - pita

Ride it to your local petrol station, throw some fresh fuel in it, give it a hiding and it should be all sorted by then. Then try 15min reset

I'm pretty sure that the BGP big grey plug has moisture in it! Lowrance will agree with me, isn't it John?!?

Open it up clean it out and dry, put dielectric grease in it and mostlikely the problem will be fixed.

Try this before swapping and breaking things!

Thanks for the help.

Mine did that for the first couple of rides after the battery had been disconnected, now back to normal.