Few questions about 03 YZ450

So i just picked up my 450 in early december and have a few questions,

First off im getting a weird hesitation at the top of 4th...like itll jolt forward and then suddenly die out, and repeat...the bike is completely stock and im thinking its a tuning issue, anyone else have this problem?

Secondly im having a problem stalling out on tight technical trails, is gearing enough for most people, or should i consider a flywheel? I still want to be able to hit the tracks and have the zip that it does stock...suggestions would be appreciated.

Thanks

Tom

An 8oz. flywheel weight will help the '03 substantially. I have actually just ordered one for mine. The moderator over in the off-road section said that an 8oz on a 450 would help in the woods but would be a hinderance on the track. I bet the hesitation is just a jetting issue try the jetting forum for that. Lastly, first gear on the YZ450 is tall. The main fix for the stalling that I have heard is dropping a tooth on the front when you ride single track. Other than that I dont know. I dont have a whole lot of single track where I ride.

Go with the Dr.D 8oz flywheel.

I run mine two teeth higher than stock, and I ride in some fairly tight stuff some of the time, but most of my riding is 2nd and up. To each his own.

Is your weird hesitation only at the very top of 4th? Or does it do that in fourth at a lower than wound out rpm? If it's only right when it runs all the way to the top, it's probably the rev limiter. The limiter cuts of the ignition at 11,500, and turns it back on at around 10,900-11,100.

If it breaks up short of that, it could be jetting or a restricted fuel supply, or a bad plug, but it should act up in 3rd, too. If only in 4th, and it feels very harshly jerky, like the chain slipping on the sprockets, it might be from a worn 4th gear/bent shift fork allowing it to hop in and out of gear.

One other possibility that would also show up in more than 4th is if the neutral switch or the wire leading to it is shorted; that would lower the rev limit to 7000.

Thanks for the replies guys, i went ahead one bought a 13T front sprocket today and shortened my first gear a little bit which i was looking for i think im gonna buy a 51 tooth rear sprocket, and if its still not enough after that ill go with the flywheel, as far as the 4th gear hesitation it is only at the very top of 4th pinned, my only reaosn for concern is that i dont feel like im going that fast..what is the top speed supposed to be on these things?

Thanks for all the info

-Tom

I dont know an answer for your first question. clutch slippage???

So you want to ride a yz450 in tight woods trails? This bike is not designed for this type of riding. Your bike will overheat constantly and has too much power to get the kind of traction needed.

A couple easy things to start with would be to up the idle some, keep a fresh plug in it, use a good quality premium unleaded gas, lube the clutch/cable often because your gonna use it alot in tight trails(lessens strain on hand).

I wouldnt worry about a flywheel weight just yet. My gearing on my 03'yz450 is 14/49 and works well although I get to the rev limiter pretty quickly sometimes.

Have fun, this is a narly bike we've got! :thumbsup:

I dont know an answer for your first question. clutch slippage???

So you want to ride a yz450 in tight woods trails? This bike is not designed for this type of riding. Your bike will overheat constantly and has too much power to get the kind of traction needed.

A couple easy things to start with would be to up the idle some, keep a fresh plug in it, use a good quality premium unleaded gas, lube the clutch/cable often because your gonna use it alot in tight trails(lessens strain on hand).

I wouldnt worry about a flywheel weight just yet. My gearing on my 03'yz450 is 14/49 and works well although I get to the rev limiter pretty quickly sometimes.

Have fun, this is a narly bike we've got! :thumbsup:

Your crazy bro.. I run my 04 in the woods 90% of the time it overheated once and it was 100 degrees out and I was real stuck... My friend who just started riding about a 8 months ago overheats once in awhile because he don't carry enough speed ...and that only when its hot out ..don't scare this guy djo269

Start with a flywheel weight it will "HELP" you with the stalling at real low speed while on and off the clutch it will also "HELP" put the power to the ground

The bike just takes some time to get used to and before you know it you won't even think about all your problems ..Its not a XR you know

P.S. if your clutch is slipping try to adjust your cable if that don't work you prob. need a new clutch

The moderator over in the off-road section said that an 8oz on a 450 would help in the woods but would be a hinderance on the track.
I beg to differ. That may be the textbook answer, but from experience with my own, it helps it on the track as much as anywhere else. It's easier to ride, and will bite better in poor traction than it does without it. I've ridden GP's with it on there, too, and the bike gives up nothing to anyone on the pavement. I flat out fail to see the downside. 8oz might possibly be too heavy for an '04, and I wouldn't add one to an '05, but on an '03, it's the ticket! :thumbsup::bonk:
I beg to differ. That may be the textbook answer, but from experience with my own, it helps it on the track as much as anywhere else. It's easier to ride, and will bite better in poor traction than it does without it. I've ridden GP's with it on there, too, and the bike gives up nothing to anyone on the pavement. I flat out fail to see the downside. 8oz might possibly be too heavy for an '04, and I wouldn't add one to an '05, but on an '03, it's the ticket! :thumbsup::bonk:

Yeah I accidently left out the "not" in that sentence. I meant to say "would help in the woods but would NOT be a hinderance on the track" Kinda funny how one word can completely change your whole sentence. In fact, dirt rider or dirtbike magazine said (cant remember which) that an 8oz. helped their 05 YZ450F and that it did NOT hinder them on the track. They said that it felt the same but hooked up remarkably better.

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