There are few points you should notice.
- Clean and Check IACV
- Tappet adjustment
- Check and Tighten up all bolts

In ozhonda forum, there are many good DIY jobs in DIY section. Hope it may help !!

DIY tappet adjustment
http://www.ozhonda.com/forum/showthread.php?t=15443

IACV clean / check !
http://www.ozhonda.com/forum/showthr...highlight=IACV

Replaced IACV and Still High revs ?? FIXED !!
http://www.ozhonda.com/forum/showthr...highlight=IACV