Just Bought an 03 450!!!

16 replies to this topic
  • TIG88

Posted December 13, 2008 - 10:56 AM


Hey guys as the title stated i just bought an 03 yz450f. Let me just say this bike is INCREDIBLE! It is one hell of a step up from a worn out ttr 225! I will be using it mostly for some trail riding and such. There will be no motocross or anything mainly because there are none around here that I know of.

It has a full exhaust and new sprockets. The chain it is worn and will need to be replaced, anything good for the type of riding I will be doing?

The guy I bought it from said the motor has never been opened up. I just popped the valve cover off and checked the cam chain and it is fine. My question is do you think I should throw a new top end in it anyway, even though it is pretty much fine? It starts easily and dosent smoke or anything, except for a little puff of blue when revved cold, although this is barely noticeable and clears once it is warm. I wont be racing so I dont care if its not making peak hp, as long as it dosent gernade itself.

I took it down a dirt trail this morning and was in 4th gear, doing somewhere between 50-60 mph Id say, and gunned it. This thing wheelied like nothing, its just amazing! Im completely in love. It also handles in the woods better than my ttr, although Im still getting used to the height differences. Thanks guys :thumbsup:

  • tdamore

Posted December 13, 2008 - 03:24 PM


Congrats, I bought one about 4 months ago and love it. Read all the sticky threads about common issues etc. I would check the valve clearances but other than that I think you are good to go. If you are doing 4th gear wheelies I think your top end is fine.

  • DMC707

Posted December 13, 2008 - 08:24 PM


sounds like fun bro, enjoy. As far as mechanical issues go, im the wrong guy to ask unfortunately (never had any probs)

  • Ga450owner

Posted December 14, 2008 - 09:37 AM


for your type of riding a flywheel weight will be in order. The 03 is notorious for rear wheel spin....this is not good for woods riding.
I also suggest a StormRacing linkage to help it corner better...it is a tall, heavy beast in the woods...no comparison to any TTR
and finally a 18inch WR rear wheel ....otherwise overtime and roots/rocks you will destroy a 19wheel

  • TD-3

Posted December 14, 2008 - 03:11 PM


You will probably have to change the crank before the valves on an 03.

  • TIG88

Posted December 16, 2008 - 10:35 AM


Hey thanks for the replies guys. Where I live there arent a whole lot of rocks or anything, just kinda low lying marsh stuff and woods. I'll forgo the WR wheel for now. I was originally in the process of buying an 06 wr, but the 03 YZ came up at such a good price I couldnt say no.

So far the woods riding has been going pretty well. It def needs a flywheel weight. A little blip of the throttle by accident would not be fun the way it is now. Ive put maybe 10 hours on it now, and I still cant believe it. The suspension was set up for the previous owner, who was the exact weight and height as me (5'11, 180#). Right now it feels pretty good. The front sprocket has one extra tooth than stock, so it goes pretty slow. Usually dont use 1st gear unless its really tight in the woods, its just too squirelly.

It starts easily so I doubt the valves are too far out of spec but i'll take a look this weekend. Is it overly difficult to do? Anything else I should look out for mechanically?

Thanks again for all the replies. :thumbsup:

  • yamaha racing 230

Posted December 16, 2008 - 02:14 PM


were in Maryland do u ride at ?

  • TIG88

Posted December 16, 2008 - 03:06 PM


A couple farms strewn across the upper eastern shore. See you live in Md too, and used to have a 400 huh?

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  • 450 vet

Posted December 26, 2008 - 10:57 PM


congrats,the 03 450 was/is a beast,even by today standards.My buddy i ride with has a 07 450yz and it doesnt hit like the 03,the 03 is just ignorant imo.

  • DPW

Posted December 27, 2008 - 07:43 AM


an 8oz Dr.D Flywheel will work wonders.

  • yz_for_me

Posted December 27, 2008 - 09:43 PM


I've got a 9 oz GYTR FW on mine. It made a huge difference and would highly recommend something in this range. Even a 10-12 oz wouldn't be bad on an '03 if you ride really tight woods.

  • hillclimbguy

Posted December 27, 2008 - 11:48 PM


Congrats on the new bike. The 4 speed makes it diffucult to ride the tight stuff. Either geared too tall or too low. A flywheel will help as well as an 18 in rear wheel. You might be able to look for a WR transmission. Just depends on how much work you want to do for your bike. Good luck. Be safe

  • Justin89

Posted December 28, 2008 - 12:02 AM


Congrats on the new bike! Prepare for your arms to get ripped off:banana: :busted:

  • VE_SS_LS-2

Posted December 28, 2008 - 02:20 AM


If it has new sprockets, then get a new chain on it ASAP or the old one will flog the shit out of the new cogs

  • TIG88

Posted December 28, 2008 - 01:05 PM


Hey thanks for all the replies guys! Anyone have any links to any good chains? Nice oring chain or something better?

Does anybody have a flywheel puller i can borrow? Or can you get it off some other way?

  • FinchFan194

Posted December 28, 2008 - 02:28 PM


I have an 04 that rips and I just put on a Regina Xring chain and it is wearing like iron I haven't even needed to make an initial stretch after about 8 hours on it. Does anyone recomend a flywheel size for an 04 for tight to open woods riding I have some serious rearwheel spin also?

  • jf52

Posted December 30, 2008 - 10:48 PM


I put a Regina X ring on my 03 and did the initial adjustment after 8 hrs of dune riding, it's been 6 months and have never needed to adjust it.
Love the 03 450.

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