Yz450f must do desert mods

[JakeNorthrupYZ450F]

Getting into desert racing and am wondering what is the most important mods for the yz450f for desert use?

I've been riding a 2012 yz450f completely stock except for Clarke desert tank and love it.

Mapping? Flywheel? Gearing? Exhaust? Suspension? Other?

Also as a sidenote, any tricks for starting the bike at the beginning of races?

[15thumper]

Tank, hand guards, suspension softer, more sag, map softer hit higher revving, kickstand for dead engine starts, pre filter for dust

[Conner_Steezel]

18 inch rear wheel is a big one. Give the bike more top end. Also gearing 14/15 tooth front sprocket. Also a steering stabilizer is highly recommend.

[grayracer513]

An 18" rear wheel will not give the bike more top end, since it will be the same effective diameter as the 19" the bike comes with.  Some people prefer the 18 because the sidewalls of the 110/100 tires are taller, allowing more rim protection with less air pressure; a good thing in the big rocks.  I personally stay with the 19 because I don't like how the heavier tire makes the bike handle.

 

Nobody has mentioned a skid plate yet, and you will want one that protects the outer/lower parts of the engine (water pump, etc.)

 

Gearing is a conundrum.  If you gear for better speed, your low gear is going to be a pain in the ass in the tight rocky climbing stuff.  If you gear down for that, you'll loose too much on top.  I used to run one tooth higher than stock at the rear, and that worked OK except for the lake bed runs, where I had to back off a little. 

 

There are two things you can do about that, but both are expensive.  One is to install a Rekluse auto clutch like the Z-Start Pro or the Core EXP.  That clears up the low gear problem almost entirely, and will even allow you to gear higher without handicapping you low speed operation. 

 

The second approach is to swap out the 4th and 5th gear pairs for those from a WR450 (for the '10+ models, you will need the WR450 output shaft also).  This effectively gives you the exact same first 4 gears as the 4 speed YZ450 had, plus the WR 5th gear as an overdrive.  Once I did that, I actually lowered the gearing from 13/48 (one over stock) to 13/50.  85mph in the dirt is a simple matter now, and low gear is lower in the bargain.

 

Starting: The bike has to start reliably.  The engine temp may come into play here, how you warm up for the start, that sort of thing, so you're going to have to work on your routine and get it down pat.  Most YZ450's will not start in gear, but you may find a trick that works for you.  I just leave mine in neutral.  On the starting line, focus only on starting the bike until it's running. Then snap it in gear and go.  Remember, you aren't going to win your first race, so don't worry that you aren't in front.  If you stay calm and tend to getting started and off, you'll be surprisingly close to the front anyway, and it's a long race.  Don't try to beat  anybody but yourself your first time out, just concentrate on learning and finishing.  Have fun!

[JakeNorthrupYZ450F]

An 18" rear wheel will not give the bike more top end, since it will be the same effective diameter as the 19" the bike comes with. Some people prefer the 18 because the sidewalls of the 110/100 tires are taller, allowing more rim protection with less air pressure; a good thing in the big rocks. I personally stay with the 19 because I don't like how the heavier tire makes the bike handle.

Nobody has mentioned a skid plate yet, and you will want one that protects the outer/lower parts of the engine (water pump, etc.)

Gearing is a conundrum. If you gear for better speed, your low gear is going to be a pain in the ass in the tight rocky climbing stuff. If you gear down for that, you'll loose too much on top. I used to run one tooth higher than stock at the rear, and that worked OK except for the lake bed runs, where I had to back off a little.

There are two things you can do about that, but both are expensive. One is to install a Rekluse auto clutch like the Z-Start Pro or the Core EXP. That clears up the low gear problem almost entirely, and will even allow you to gear higher without handicapping you low speed operation.

The second approach is to swap out the 4th and 5th gear pairs for those from a WR450 (for the '10+ models, you will need the WR450 output shaft also). This effectively gives you the exact same first 4 gears as the 4 speed YZ450 had, plus the WR 5th gear as an overdrive. Once I did that, I actually lowered the gearing from 13/48 (one over stock) to 13/50. 85mph in the dirt is a simple matter now, and low gear is lower in the bargain.

Starting: The bike has to start reliably. The engine temp may come into play here, how you warm up for the start, that sort of thing, so you're going to have to work on your routine and get it down pat. Most YZ450's will not start in gear, but you may find a trick that works for you. I just leave mine in neutral. On the starting line, focus only on starting the bike until it's running. Then snap it in gear and go. Remember, you aren't going to win your first race, so don't worry that you aren't in front. If you stay calm and tend to getting started and off, you'll be surprising close to the front anyway, and it's a long race. Don't try to beat anybody but yourself your first time out, just concentrate on learning and finishing. Have fun!

What is your opinion on a flywheel weight? It should help with the low gear problem and help with traction?

[grayracer513]

Yes on both points.  It absolutely does help with traction, and that is from experience using one on an '03.  If it helped that bike, it will improve traction on pretty much anything.

 

Because it helps prevent the engine from loosing as much speed between power strokes, it make the engine less likely to stall, and will let the engine pull more smoothly and harder at lower RPM than it can without the added weight.  With or without a Rekluse, yes, the flywheel belongs at the top of the list, especially at the price.

[rhinoracin]

I mainly ride my 09 YZ in the desert, has the 9 oz flywheel with stock gearing. I'm getting kind of tired of 1st gear being too tall in tight sections, and 4th/5th gear being too short on fire roads and sand washes. For everything in between it seems like I need to shift too much and end up revving the sh*t out of the bike. I don't have the time to do a WR gear swap now, but it's about time to replace the chain and get new sprockets so I'm wondering whether to gear up or down a little. I ride medium/fast terrain more than single track, so I will probably go down 1-2 teeth on the rear sprocket. Will this help spread out the gears a little so I won't have to shift as much? ..I hope I wont notice the difference in 1st gear.

I don't want to do a rekluse clutch. When doing the WR gear swap, should I get all 5 gears, and how much do all the parts cost?

[grayracer513]

 

I ride medium/fast terrain more than single track, so I will probably go down 1-2 teeth on the rear sprocket. Will this help spread out the gears a little so I won't have to shift as much? ..I hope I wont notice the difference in 1st gear.

I don't want to do a rekluse clutch. When doing the WR gear swap, should I get all 5 gears, and how much do all the parts cost?

 

Lowering the overall gearing "compresses" the ratio set so that the gears are closer, not wider apart, so it would have the opposite effect you're shooting for.  

 

The WR450 comes geared 13/50 and has a 25% lower first gear than the YZ450, which comes geared 13/49.  You'll notice the difference immediately. 

 

If you are going to do the 4-5 swap only, it will allow you to lower the overall gearing a considerable amount.  You could go with 13/52, which would give you a first gear close to a stock WR, and still be 6 mph faster in 5th at 9000 RPM, although it will close up the ratio gaps 1-3 rather noticeably. Third in both bikes is nearly the same ratio.

 

Swapping 4th and 5th requires only the four gears in the two pairs, nothing else.  The full WR box will require all nine gears and the WR main shaft (first gear pinion is cut directly on the shaft), which makes it a much more expensive proposition.  Roughly $180 one way, and about $700 the other, not including gaskets or bearings or piston rings, etc.

[CSAR FE]

Skid plate, radiator braces/guards/cages, desert tank, steering stabilizer, hand guards, levers that won't break (so you aren't stranded way far out), a good soft/intermediate terrain tire, heavy duty tubes (unless you want to run a mousse or Tubliss), bars with a comfortable bend and good flex, Getting your suspension set up specifically for desert is probably one of the best things you can do.

I can't speak to the flywheel, but it's on my list to try. Basically anything you can do to protect critical components, extend your fuel range, reduce rider fatigue and make the bike as stable/smooth as possible is what you're looking to do for a desert bike.

Edited February 27, 2016 by CSAR FE

[rhinoracin]

Lowering the overall gearing "compresses" the ratio set so that the gears are closer, not wider apart, so it would have the opposite effect you're shooting for.  

 

The WR450 comes geared 13/50 and has a 25% lower first gear than the YZ450, which comes geared 13/49.  You'll notice the difference immediately. 

 

If you are going to do the 4-5 swap only, it will allow you to lower the overall gearing a considerable amount.  You could go with 13/52, which would give you a first gear close to a stock WR, and still be 6 mph faster in 5th at 9000 RPM, although it will close up the ratio gaps 1-3 rather noticeably. Third in both bikes is nearly the same ratio.

 

Swapping 4th and 5th requires only the four gears in the two pairs, nothing else.  The full WR box will require all nine gears and the WR main shaft (first gear pinion is cut directly on the shaft), which makes it a much more expensive proposition.  Roughly $180 one way, and about $700 the other, not including gaskets or bearings or piston rings, etc.

 

https://rekluse.com/wp-content/uploads/2015/08/Comparison-Chart.jpg

 

Decided I might want to try an auto clutch if I can still have a normal-feeling clutch lever, and it looks like the Rekluse core EXP does that. Will the lever pull actually feel how it does stock? I want to be able to use the clutch normally and only have the Rekluse there for when I want it in first gear-technical riding. Also like that Rekluse says their clutch is tuneable, but how is that done and what happens when you adjust it?

Will get new chain/sprockets first, and I would like around 10 mph gain in 5th gear with gears 2-5 spread out a little, but not too much...so I'm thinking a 14T front sprocket. Gotta figure out how many teeth for the rear.

Edited April 15, 2016 by rhinoracin

[grayracer513]

Haven't ridden with a Core EXP, so I can't say for sure, but that's what they say.

 

I don't follow your last sentence regarding gearing.  14 tooth front with what gearbox?

[rhinoracin]

Stock '09 YZ gearbox. Currently have original sprockets too.

[grayracer513]

Ok.  Going to a 14 in front will gain 6 MPH at 9500 RPM in 5th.  A 15 will net 12 MPH.  In combination with a Rekluse, that may work OK, but first will be a bit tall that way.