I have a 2007 YFZ450se, piped, jetted, air filter, airbox lid removed. I am looking to do some more mods on it but don't kno where to go from here. what should my next few upgrades be for maximum performance?

 

head work get it port and polished by someone who knows what they are doin put some cams in it

 

cam, piston, port and polish.

 

k, how bout big bore kit? high compression kit? also, i got a problem with my quad. i was riding it recently and drowned it in a creek trying to cross. i got it out and drained as much water as possible then got it running and rode back to my truck. by the time i got back my quad was making a high pitch whine that seemed to be in sync with my throttle, higher the rpms the higher the whine. I know that i got a lot of water in my engine from the oil. the oil resevoir was crammed full and the oil was all milky. i know water will damage and destroy bearings so i guess im just wondering if this sounds like i blew my bearings and if that is the extent of the damage or if there is more that the water can damage. ex. (cylinder, piston, head...) i haven't had the quad running yet because work has kept me busy but i drained all the fluids and did some looking around to look for damage so im not sure how it will run. any tips?

 

higher compression piston, aftermarket crank and connecting rods, most importantly port and polish the head, and you could always throw on that aftermarket yamaha CDI box too...just some ideas for ya.