This WR450F is SO hard to work on !!

[WR450FGreg]

I can't belive how hard this new WR450F is to work on.

Any carburettor work is a f....g nightmare, and yes, I did rotate the rear subframe up out of the way and remove the rear shock before I tried.

The hardest job of all was trying to get the aircleaner boot back over the rear of the carb! It must have taken me half and hour or more, even after greasing the inside lip of the boot a little and removing the clamp altogether (then bending it back over into place later.)

Does anyone have any tips for that job?

Greg

[Kirkster]

Sounds like you have it all figured out. It sucks, my first time working on the carb took me an hour and a half to get it all back together.

My tip would be to get the jetting right on the first try...

I use a silicone spray on my boot lip and outside edge of the intake side of the carb. Now it only takes me 15 min to get it all back together.

[chevytrkn1]

it is a big pain in the butt, I did all my research and figured the JD jetting kit would be the way to go so i only had to do it once

[WR450FGreg]

Kirkster,

I use a silicone spray on my boot lip and outside edge of the intake side of the carb

Good idea, I'll give that a go next time.

Chevytrkn1

Yep, me too.

I had the bike apart to fit the JD kit. There is some contention about whether to follow the instructions to the letter (ie. red needle, 4th clip position etc.) to suit Australian conditions.

I read somewhere that we need to go a bit leaner here but ended up fitting the needle as per the instructions (it should be a bit rich, which is safer to begin with) and the 170 main jet.

Standard main jet here is a 175.

I'll be taking it for a short run in a field this afternoon to try it out.

Fingers crossed it's spot-on jetting-wise! ?

Greg

[SXP]

Greg - The devil is in the shock! The trick here is to have the shock unbolted (top and bottom) BUT IN PLACE. This allows you to move the shock to the side giving you room to slip (very easily - no need for lubes) the boot back on.

[WR450FGreg]

Hey, THANKS SXP !!

I was hoping someone would be able to give me a tip or two!

What you say makes sense.

I'd like to be able to say: "Can't wait until I pull it apart next time to try it", but that would be stretching things a bit! ?

Greg

[WR450FGreg]

I'll be taking it for a short run in a field this afternoon to try it out.

Tried it out.

Still starts incredibly easily, amazing throttle response.

I think there is an increase in (seat of the pants anyway) midrange, but possibly slightly less top end, maybe a bit too lean I suspect.

I made the "mistake" of fitting the JD kit along with fitting a bigger diam. tail-pipe, fitting the thick o-ring to the accelerator pump linkage AND disconnecting the grey wire...... ie. all at the same time.

I should have done one thing at a time so I could gauge things a bit better.

Greg

[beezer]

The bike is very hard to work on but you really didn't need to take the carb off to install the jet kit. The needle can be accessed from the top and the jets from the bottom.

I use ball end allen wrenches and get the float bowl off with those. Taking the muffler off makes it easier.

I put a YZ exhaust cam in and what a PIA. The cam cover is so close to the frame it's almost impossible to get off.

Now that all the wrenching is over I'm really enjoying the bike. It's a night and day difference between it and a steel WR.

[rozero1234]

yikes! i'm glad i got an 03' haha. never thought i'd say that.

[brad the best]

if you just commit and take off the subframe , it actually doesn't take long . its all the messing around leaving this and that on that takes so long .

learned that about the third time .

[crf-rider-450]

solution - buy a honda hahaha.

na, mate has a WR thats forever under work (finx rally bike) and yeah they are naturally a b**** to work on i think.

as SXP said unbolt the shock, works a charm ?.

Rodney

[OUTERLIMITS]

I am hoping after the initial set up, there will not be much cause to go in there again anytime soon. I can only hope there will be more room for valve checks than it looks. No doubt, there is no room to spare under there. As frustrating as it is, it's really quite a marvel that Yamaha was able to engineer that kind of space utilization. Reminds me of a street bike.

[123BigcoopDawg576]

I am hoping after the initial set up, there will not be much cause to go in there again anytime soon.

your hope is correct...after the first rejet on my 06 and my buddies 07 there has been no reason to change a thing!

I can only hope there will be more room for valve checks than it looks.

whats a valve check....jk....but seriously they are few and far between...between my dads 06 and my 06 we have 8000miles and zero valve adjustments and only like 4 checks!

[Demo_Slug]

The hardest job of all was trying to get the aircleaner boot back over the rear of the carb! It must have taken me half and hour or more, even after greasing the inside lip of the boot a little and removing the clamp altogether (then bending it back over into place later.)

Does anyone have any tips for that job?

Greg

I had problems getting the boot back on to the carb after I installed a stiffer rear shock spring. My interference was with the rear shock spring. I thought about greasing the spring, but By adding more preload to the rear spring, the spring gets out of the way( I needed more preload anyway), and the boot slips back on…. easy as pie.

[OUTERLIMITS]

whats a valve check....jk....but seriously they are few and far between...between my dads 06 and my 06 we have 8000miles and zero valve adjustments and only like 4 checks!

For a diehard Honda guy, it was a tough choice, but what you state above (and I have heard it from many others) is one of the main reasons I went with the WR over the X. Time will tell I guess, but I'm hoping for that kind of success as well.

[Demo_Slug]

For a diehard Honda guy, it was a tough choice, but what you state above (and I have heard it from many others) is one of the main reasons I went with the WR over the X. Time will tell I guess, but I'm hoping for that kind of success as well.

2 of my 08wr450's valves was out of spec after 40 hours. it got kinda hard to start. some maintinance is required. I got 20 more hours on it and its still running like a top.

[MaxPower]

it looks to me like all the new 4 strokes are hard to work on

I miss the simplicity of the 2 strokes

[ETP]

Maybe you aluminum frame guys will get lucky and be able to replace the carb with the fuel injection parts that should be coming out in the next couple of years. (we hope)