stock 03 yz450f is kicking my ass in the woods

2003 yz450f.  I'm pretty sure the motor is stock. Stock(?) 14/48 sprokets and a Rekluse z start pro clutch.

 

Looking to make it more trail friendly (and novice friendly for now). 

 

Trying to ride on a budget since it is an older bike and I dont wanna invest too much into it.

 

Go with a bigger rear sproket first (51t?) or a 10oz flywheel weight? Or benifit more with both?

 

Remember It has a Rekluse and I ride strictly woods/trails.

 

Also tires are a little old... Whats a good value front and rear tire to run in the Southeast (NC,SC,GA,VA) woods?

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Edited by CJParker

I have a 50 tooth on my 2012 stock was 48 and a 9 ounce flywheel. The bike bike is way more trail friendly for the slower stuff I think do both especially if you are a trail rider. I did both and i race mx too and dont regret it but if you have too pick for money I think do the fly wheel it will smooth the power down low worth the money and pretty inexpensive.

Ps just saw you have a rekluse. I don't and have no experience with them.

Lower gearing and a flywheel weight.

What is it exactly about the bike that's kicking your butt?  The Rekluse should make it nearly stall proof, although the '03 is pretty hot tempered, and you definitely will like the bike a lot more with at least an 8 ounce weighted flywheel (welded-on ring type; bolt on eights need to be heavier).

What is it exactly about the bike that's kicking your butt?  The Rekluse should make it nearly stall proof, although the '03 is pretty hot tempered, and you definitely will like the bike a lot more with at least an 8 ounce weighted flywheel (welded-on ring type; bolt on eights need to be heavier).

Throttle control is just hard bouncing through the rough stuff. Im a bigger guy at 6'3" 200lbs but inexperienced with that much power on tap in the dirt. heard the '03 450 hits harder than any other 450. Just looking to tame it down some for the time being.

Run a larger steel sprocket to see what I like then upgrade/replace chain and sprockets later with higher quality? Motosport as Turner steel rear sprockets for $25. Gonna order a set of riding gear too, so I'll get free shipping on it also.

Throttle control is just hard bouncing through the rough stuff. Im a bigger guy at 6'3" 200lbs but inexperienced with that much power on tap in the dirt. heard the '03 450 hits harder than any other 450. Just looking to tame it down some for the time being.

Had the same problem with my 03 in the tight stuff. I got one of these- https://www.thumpertalk.com/shop/G2-Ergonomics-Tamer-Throttle-Tube-40-4Y-136-p4050271.html. No longer an issue.

To tame it down i would add a 10 oz flywheel weight, a bigger rear sprocket. One other thing that would reallly help is a CDI off a 2005 model.

Edited by Yammer-Hammer

What size rear sprocket?

about to order tonight

The throttle tube is a sensible approach for someone inexperienced with the, um, rather responsive nature of the '03 model, but if that's the problem, lowering the gearing by adding teeth at the rear will just make matters worse.  Notice that the bike is jerkier throttle-wise when it's in low gear, as opposed to second or third at the same RPM.  If you could shift to a gear lower than first, do you think that would make it smoother?  Not. 

 

There are ways of toning down the engine.  One way is potentially really cheap, and change can be made or reversed in minutes.  Try to find the CDI from a 2005 YZ450F on eBay.  That year was actually criticized by a lot of people as being sluggish (comparatively).  Plugs in, snaps in place.

10-4

Try to find the CDI from a 2005 YZ450F.

I already mentioned that

G2 throttle tube with cams is supposed to ship today. I'll try it out before adding a welded flywheel weight. And once I get it smoothed out like that, I'll add a bigger sprocket to get some stronger low end.

Best thing that ever helped me in the woods was suspension, helped me in the tight stuff and overall didn't get beat up as much and didn't get tired as fast. You mentioned a good tire and I would recommend a maxis intermediate terrain, they are very reasonably priced, last a very long time and hook up good all around, mud, rocks, roots, fields all that. I would go with a 120 on ur bike as a bigger tire will give you a little does of the same thing a larger flywheel would. Harder to get going and once you do harder to stop.

Stepcant thanks for the tire advice. I've been doing some searching and found maxis to be a well liked tire just wasn't sure to go with soft or intermediate. Looking like a maxxis intermediate 120 is next.

I would think with the rekluse you could dial in the engagement point and smooth out the bottom end a little. its been my understanding that the flywheel weight is to help with stalling but I could be wrong. on my 426 suspension setup was key, after softening everything up I find it much easier to manage in the tighter stuff

The '03 YZ450 is a lot like driving around town on a rainy day in a '69 Camaro with a 427 big block in it.  Too much power too easily accessible too soon above idle.  You sneeze, you do a burn out.  The Rekluse will help with the stalling, and eliminate the worry about modulating the clutch properly, but that's it.  The throttle still acts like a detonator.

 

The flywheel weight helps some with stalling, but it helps more with smoothing out the power flow at low RPM, so with or without the auto clutch, it's still beneficial.

 

Suspension is important alright, but it's expensive to do anything really effective to it, and the OP may not consider it worth while to spend that much on an '03.  What can be done cheaply, though, is this.  First, try a fork oil change, being sure to use a light grade suspension oil (~2-4wt) and keep the oil at near the minimum level.  With the springs removed and both the damper rods and main tubes compressed, the oil level range is supposed to be between 135 and 85mm down from the top of the upper tube.  Try it at 130.  If you can run that oil height without excessive bottoming, the lower level will make the front end fell softer.  Also, back out the compression clickers on the bottoms of the forks.  Turn them all the way in just to where they stop, then come out about 15 clicks.  If this feels too loose, bottoms too easy, etc., go back in two at a time.  Loosen up the rebound (top of the fork) some, too.  Lastly, be sure the spring rates are appropriate for your weight.  Stock springs are intended for riders weighing around 170-190 in street clothes.  Too far off from that, and the suspension will never work right until the springs are matched.

I am a smaller guy starting out in the woods on a 2009 450. Correct spring rate front and back with low weight oil in the forks, setting the sag , and the gytr heavy flywheel all helped me out tremendously. It was like a totally different bike both with both changes(suspension and flywheel). I used the lower range oil level in tubes as well.

Questioned my decision at first with 450 but absolutely love it now.

Oh, yeah, the 03 is definitely a handful. I like the comparison to the big block V8 in town on wet roads!

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