Yz450f 2008 trail mods

Hi guys.

I've had this bike for a while, and it's an awesome machine with awesome power, but i find it challenging when riding single trails.

I've got 51 tooth sprocket at the rear, but I'm still finding it stalling from time to time.

What mods do you guys recommend that would make it more usable in slower technical areas.

Riding in BC Canada.


13/52 sprockets, and a weighted flywheel.

When I rode the 08 a flywheel sure helped along with gearing. The BC trails can be a tight gnarly day on the bike for sure!

18 rear wheel helps a lot, and a rekluse make everything easy!

Looking into flywheel already, it's only $120 shipped.

I'm unsure on recluse, I know that it would be breeze, but it would turn it almost into automatic car.

What would be advantage of 18 " wheel on rear?


A WR wide ratio transmission would be just the thing too.

18 is alot easier to manage and just works better all woods bikes come stock with them. and the rekluse is not automatic.

Yes I know that recluse it's not automatic (used wrong wording)

Actually spent quite of bit of today researching details about it, and considering picking up used exp 2.0.

Should I also consider picking up weighted flywheel? Any advantages of having both mods on bike.

Thanks. Can't wait till next Saturday.

I've got a 09 that I have only taken on one real trail ride and I have the same concerns as you. It stalls a little too often to replace my current trail bike. I was thinking a heavy flywheel would be my first mod. I'm curios to see which mods you feel are the most effective.

There are no disadvantages to the heavy flywheel that I have experienced on trail or track.

13/52 sprockets

Heavy flywheel

Suspension set for my weight/trails

I have ridden my 09 with this setup on the black coal national enduro course in Lynnville, IN.

A rekluse is on my wishlist but I want to get good at manipulating the clutch manually before I go dropping that kind of coin.

In had flameout issues at first, I turned up the idle and it helps immensely. NO COIN INVOLVED!

Ok, so I've missed auction on that recluse clutch, but I've ordered weighted flywheel from rockymountain, should be with me by Saturday. Will report differences after 1st ride.

I had a recluse, don't bother.. You ride McNutt?? For tech BC stuff you want to banging that clutch like its the end of the world, not that sissy automatic flame out garbage . get Tubliss 19", Sedona 907HP.. Run it flat, 0psi. Run the shortest gearing you can.. 13/52 or the like. I put WRF gears in mine, well worth splitting the cases for. Its 95% rider, 5% bike. I rode my clapped out 87 cr250 with 15 year old bald tires through the harder trails in WA... Just have to learn how the bike likes to be rode.. Pin it to win it!

I have a 51 on the rear and I just put on a 9.2 oz weighted flywheel. It definitely helped on the tight trails. Being quick with the clutch doesn't hurt either.

I have an '09 with flywheel weight, 13/51 gearing, turned up the idle a bit, and it rarely stalls like it did before the gearing and idle change.  13/50 gave me fits in singletrack.  If all you ride is tight trails, a 13/52 would be the way to go.

You don't want the 2.0 rekluse anyway. Get the 3.0 exp set up properly, you will not take it out. If for somereason you don't like they have a 30 day money back guarentee.For rocky rooty steep single track its insane, luv it!

I have an 06 that I have used on single track and it does take some getting use to after. I tried turing up the idle but didn't like how it pulled me in spots I didn't want to be pulled in. I have a Rekluse z pro on the wish list to go in during the winter, just getting use to the bike is biggest thing I noticed since now I don't stall it as much but the flywheel will make a difference if you can't do the rekluse.


The mods I did for mine for the trail were a full skid plate, a kick stand ( I went with a pro moto billet since it was a better design than the trail tech), trail tech vapor to keep an eye on the motor temp and just see how fast I'm going and how far I went, full aluminum hand guards and an oversized gas tank with reserve pet cock but if you can't do the gas tank look into a petcock with a reserve to make sure you have some gas to get you to a fill up. I plan on routing the breath lines to the air box this winter to make sure if I do a water crossing I don't suck any water up in to the line.

Edited by 700rScott

We have some tight woods here in western Washington as well. My theory on tight woods is that you want to be as smooth as possible over all the roots and rocks.

I run a zStart Pro Rekluse clutch. The Rekluse clutch is the single best modification you can do to your YZ for the woods. Just because you have a Rekluse does not mean that you never touch the clutch. I set the clutch to engage immediately off idle and while riding in tight/gnarly stuff I am constantly working the clutch to smooth things out, control wheelspin, etc. The nice thing about the Rekluse is that the clutch pull is much easier, plus you have the added benefit of not having to be perfect 100% of the time. The guys that suffer flameouts with the Rekluse are the guys that never touch the clutch lever.

I am adamantly against gearing the YZ down. When you gear the bike down it becomes jerky and over-reactive to even slight throttle modulations which in my experience compounds the problems of roots and rocks. It also reduces the useable range of each gear which means you have to shift more often. Stick with your stock 13/49. Again, I am very familiar with tight, rocky, rooted, muddy trails.

An 18" rear wheel is nice as you have more sidewall which translates into more flex. This allows you to run lower air pressure to absorb roots and rocks rather than skipping and bouncing over them. It's an immediate difference maker.

Since your speeds are lower in the tight woods a good coolant is very helpful. Make your own...80% water, 20% ethyl glycol coolant (Prestone or whatever from an auto parts store), and a capful of a surfactant such as Redline Water Wetter. The water cools the engine, the EG lubricates and prevents boiling, and the surfactant breaks the tension of the water and allows for better transfer of heat from the metal to the water. It works every bit as good as Engine Ice at a fraction of the cost.

The stuff that makes my YZ good in the woods:

Rekluse clutch

Yamaha weighted flywheel

13/49 gearing (stock)

18" rear wheel

Suspension revalved by TBT

Of course there all the other offroad stuff like hand guards, skidplate, bigger tank, etc., but those are the things that make it fast in the woods.

Heavier flyweight is installed already. Haven't had chance to test ride it tho. Hope it will fix my stalling issue.

Heavier flyweight is installed already. Haven't had chance to test ride it tho. Hope it will fix my stalling issue.

You will like it

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now