hi i just recently boght a 2005 yfz and was wondering if i should be wary of anything.was there any defects with this year and if there are what are they.

 

I know the '04 had a plastic plug in the engine where the decompression line went in on the yzf dirbike. It was known to crack and pop out blowing all your oil everwhere. I want to say that it was fixed in '05 but, check and make sure. You can pick up a metal replacement cheap and it's easy to install.

Then there's something about oil not reaching the underside of the piston properly and the fix is to completely tear down and do some other stuff. I"ll cross that bridge when I get to it.

 

well it hasa new sleeve and head and other engine stuff that i prolly don't know about.

 

NEXT time you rebuild your engine do the oil mod with a new 07 oil pump. Here's a link for the mod http://www.jtatv.com/yfz450-oil-upgrade-kit.htm
Before you ride it again, change the oil and clean your air filter. Do this every 4-5 tanks of Premium gas and maybe you will only have to rebuild every other year!
Good Luck!!

 

Oh, one other defect, YFZ's have an inherant ability to empty your wallet (for more power, speed, ect..), but they are so much damn fun!! I have a friend who has a built Raptor and I wouldn't trade him for anything! We do a lot of trail riding and he has a hard time keeping up with me. Now if we get in an open field he will smoke me, but nothing handles better than a YFZ!!

 

<div class="FTQUOTE"><begin quote>Originally posted by: sluckman

... and maybe you will only have to rebuild every other year!

Good Luck!!</end quote></div>

Man if your rebuilding every other year than you must be racing or abusive (which you don't seem to be if change oil that often). No need to rebuild that often. Rebuild when it's needed. Have had mine two years and guy before me had it rebuild a year before I bought it. It's nowhere near time to tear into it.

 

ya i was gona say i really dont want this bike if i gotta rebuild every other year lol. but is the thing with the oil on the underside of the piston a really big deal?

 

Mine's an '04. First year. Guy I bought it from had it rebuilt but, he raced it. He didn't have it done. So.. I think ya, it should be done IF you already are in the engine. Otherwise I wouldn't and haven't messed with it.

I've read that the racers had the most problems with it because they keep the engine at high rev's constantly. At sustained high revs the underside of the piston is not getting oil'd properly. Everyday riders didn't have near the trouble with it.

I really wouldn't let it keep you from getting the bike. Chance's are you won't ever see problems related to it.

 

ya i have it and love it.way better than my warrior.almost a 2 stoke feel.anything i can do to give it a little more power?

 

First off I'd get the proflow kit to replace the crap stock filter setup. Then save up for pipe and rejet.