Converting a WR into a "WZ"

[New_2_4Strokes]

My son is ready to begin the move from 2-strokes to a 250F. Due to our current bike inventory and my desire to keep matrimonial harmony, we are not going to add to the fleet this year, but rather want to turn my ’05 WR into a “WZ” until it is time for him to get a real YZF. I don’t want to do anything permanent or expensive, so close is good enough, but I do want to add some snap, remove some weight, lower the center of gravity, etc.

In addition to all regular free mods, my “WZ” specs call for:

·YZ exhaust cam (I have an ’04 already)

·YZ exhaust (already running it)

·YZ number plate

·Remove odometer (leave hub, but plug hole)

·Remove e-start and battery (any wiring tricks to this?)

·Open airbox side holes (rejet, of course)

·Lower radiator 1” (I have Dr. D. kit for YZ and made extra bracket for the WR's 3-point rad mounting)

·Move forks up 5mm

·Remove coolant overflow bottle and tubing (route overflow hose like YZ)

·New sprockets for YZ gearing

·New non o-ring chain

·Remove kickstand

Seems simple enough. Has anyone else done this? Have I forgotten anything?

Thanks.

[Way Fast Whitey]

·Remove e-start and battery

·Remove coolant overflow bottle and tubing (route overflow hose like YZ)

·New non o-ring chain

i just need to ask WHY?

e start can come in very handy

the over flow bottle is a great add on, personal i would leave it if hes gonna be doing ANY slow riding

you should repalce your final drive components often but why switch to non o ring?

[BIGBLUEKNIGHT]

i could see ditching the e start but why get rid of the overflow bottle

[New_2_4Strokes]

I probably should have mentioned that my son is an MX, not woods/trail, rider.

Removing e-start/battery is to reduce weight and lower COG, plus my son needs to learn kick start routine on the 4 stroke. Weight and COG are also the drivers behind removing the overflow bottle. Bike will be used on MX track only in this form, so slow riding is not a real issue, but perhaps there's not enough weight saved there to matter. Would go with non o-ring since it is cheaper and fine for MX application. When restored to WR form, all stock parts would go back on.

[barton]

Change the PAJ from 75 to the YZ's 100, and re-jet.

[Bill_P]

My son is ready to begin the move from 2-strokes to a 250F. Due to our current bike inventory and my desire to keep matrimonial harmony, we are not going to add to the fleet this year, but rather want to turn my ’05 WR into a “WZ” until it is time for him to get a real YZF. I don’t want to do anything permanent or expensive, so close is good enough, but I do want to add some snap, remove some weight, lower the center of gravity, etc.

In addition to all regular free mods, my “WZ” specs call for:

·YZ exhaust cam (I have an ’04 already)

·YZ exhaust (already running it)

·YZ number plate

·Remove odometer (leave hub, but plug hole)

·Remove e-start and battery (any wiring tricks to this?)

·Open airbox side holes (rejet, of course)

·Lower radiator 1” (I have Dr. D. kit for YZ and made extra bracket for the WR's 3-point rad mounting)

·Move forks up 5mm

·Remove coolant overflow bottle and tubing (route overflow hose like YZ)

·New sprockets for YZ gearing

·New non o-ring chain

·Remove kickstand

Seems simple enough. Has anyone else done this? Have I forgotten anything?

Thanks.

Well, you've got a bunch of mods there that leave me wondering "why the he!! would he even bother, but if that's what you want - by all means do it. You will lighten the bike a bit, but it seems like a ton of work for very little gain IMO. What will make the biggest difference you didn't even touch on - A YZ tank/seat combo is a must if you want it to feel like a YZ. I'd also suggest getting the suspension worked on if he's MX'ing the bike. The stock suspension will most likely be too soft for big jumps unless he's a featherweight or doesn't jump high/far.

[Birdy426]

Bill P hit the target with the YZ seat and tank...also, ditching the WR rear fender for a YZ fender will not only save a couple of pounds, it will add style points.

I don't know if I'd go with YZ gearing, either, as the transmission ratios are different between YZ and WR. Get the internal tranny ratios and compare the two, and change the gearing to match the overall ratios in first and fifth as close as possible.

[JSanfilippo]

Bill P hit the target with the YZ seat and tank...also, ditching the WR rear fender for a YZ fender will not only save a couple of pounds, it will add style points.

.

Hes doing this to an 05, the seat/tank transition isn't as awkward as the 01-02 models. YZ fenders on WR's look sick I must agree

[Westerkulla]

If riding MX, why not buying a YZ with proper gearing in the first place?

Exhaust and exhaust cam:thumbsup: Does anyone ride with wr cam&timing anyhow?

Airbox mod My '02 wr276 goes happily to the rev limiter with airbox cover&snorkle in place. I'd like to see some dyno evidence about the power gains before making my bike suck more dust&water?

Removing overflow bottle:thumbsup: I've got very little coolant loss even at trials speeds. I suppose it depends on the climate, though, here it's rarely over 25 C in the summer. Actually, I'm planning to make a toolbox out of the overflow bottle, anyone tried this?

Chain replacement:thumbsdn:

Radiator lowering:confused: I notice the difference when the 8 litre tank is empty or full, but dunno bout 1 in radiator height difference?

Remove e-start and battery:thumbsdn: I think we are going to see e-starts in all production mx bikes pretty soon. Too many races have been lost because of stalled engines.

[splitpunk]

1st off E start is the bomb . I kicked mxers and Harley's for years e start is really nice. Then again I paid my dues... Next with all the changes you could just about pay for half a new Yz. save a little and buy the new bike. Done ride it till it breaks and then build it the way you want it in a couple of years or so. Just a thought

06wr250 free mods Fmf 4.1Ti powerbomb, re jet

TTR125 wifes

TTR125 girls

TTR90 & TTR50 the boys.

[Dano426]

Next with all the changes you could just about pay for half a new Yz. save a little and buy the new bike.

I would have to agree with splitpunk. By the time you remove everything and make the YZ change you will have spent enough money for a different bike and still have a WZ. Don't forget that you need to revalve the WR suspension for your sons wieght for the MX track. MY $.02

[New_2_4Strokes]

Thanks for all the input. Here's all I did:

- Removed odomoeter

- Removed battery

- Left all other electric start components

- Cut out airbox side holes (tuned fuel screw w/ JD jetting kit)

- Installed YZ front number plate

- Lowered Rads 1" with homemade kit (easy to do, but major plus!!!)

Bottom line: my "WZ" turns like a 125. That had been a weakness. Now it feels way lighter with lower center of gravity. I kid you not. Tested it against my 13 year old son riding his Eric Gorr Suzuki 100cc 2 stroke supermini (FAST!). I'm 50. He's 13. He is absolutely faster. Took him 20 laps at our backyard track to catch me though! The WR has much potential to be unlocked!

[DirtJunky]

thats what im going to do when i get one.. that way i have a green sticker bad boy. you should have weight the bike before and after. im guessing around 10lbs plus weight savings... grab all the parts you took of and weight them. im curious

[k-80]

Your boy Is got a very cool dad.

[m0tyrider]

Id say definatley save more and buy the YZ. Why mod a WR so much...you clearly dont want a WR for its Enduro purpose...so ge ta YZ for the MX... just seems logical?

Why get a WR and ride it on MX when u can get a much more divine machine?

Perhaps im missing something...

[New_2_4Strokes]

Total weight savings was about 9 lbs., but impact is even bigger since it is all on top. Total investment was nil and I could convert back to e-start in 5 minutes.

For those that wonder why I would go this route with a WR vs. getting a YZ, I will get my MX'er son a YZ when he is ready, but he is just now getting to the point where he can begin to ride a full sized bike. Since I have the WR, I thought why not give it a shot. Since my son's a small guy, I wanted to make my WR an easier ride for him on the track without making it a problem for me to ride in the woods. I think I've found a great balance. Unfortunately, this little experiment has worked so well that the track bug has bit me again.

[Wakerider13]

Total weight savings was about 9 lbs., but impact is even bigger since it is all on top. Total investment was nil and I could convert back to e-start in 5 minutes.

For those that wonder why I would go this route with a WR vs. getting a YZ, I will get my MX'er son a YZ when he is ready, but he is just now getting to the point where he can begin to ride a full sized bike. Since I have the WR, I thought why not give it a shot. Since my son's a small guy, I wanted to make my WR an easier ride for him on the track without making it a problem for me to ride in the woods. I think I've found a great balance. Unfortunately, this little experiment has worked so well that the track bug has bit me again.

good job... why spend 6g on a new bike that you guys don't need yet... but start saving

[whoops dude]

Id say definatley save more and buy the YZ. Why mod a WR so much...you clearly dont want a WR for its Enduro purpose...so ge ta YZ for the MX... just seems logical?

Why get a WR and ride it on MX when u can get a much more divine machine?

Perhaps im missing something...

why buy a new bike when for the time being you can just work with what you already have.