125-200cc New bike. 144 or 165??

Hey everyone,

I'm new to the forums and have been pretty busing doing some research on here. A lot of great info. I recently picked up a 2013 wr125 with about 2 hours on it. Bike came with 144 kit still in the box. I like the bike a lot but definitely looking for some more low end for single track/enduro type riding. I'm 6'0" and 195 lbs. Coming off of a 12' ktm 250xc. Trying to decide if I want to put the 144 kit on or sell it and wait for the wb165 kit. May be even some porting and head work. Any suggestions? Thanks

The bike comes geared 13/50 which is to tall every where Best all around is 13/52 and if you really want some fun in the tight go 12/52 I can ride my 125 anywhere I ride my 165 Start first by gearing then if you need more work on the motor

Ok, I'll definitely look into some gear changes.

Go 144 and get an FMF pipe for it. It will be a completely different bike. If you can afford to, either send your carb into RB for mods, or buy a modded one from somebody who has switched over to a PWK.

I like the stock gearing on my 144, but I do ride about 70% motocross and 30% single track.

Your first statement was that you ride single track and enduro and you wanted more low end the cheapest fastest and quickest way to do that is gear it I have prerun King of the moto 3 times and rode the course out there many times on a bone stock 2006 CR 125 geared 12/52 I have raced KOM 3 times on my 165 geared 12/52 and won Last dog Standing 2 times with the same gearing. Still run the stock carb with setting as delivered from the factory I do run straight race
gas If you need to go faster then about 45 mph then go 13/52 and it will go about 65 mph The reason I post this is it really is a cheap way to make your bike work you can have all the fun you want with a stock motor. The bike flat will not pull 13/50 stock gearing even on the flat wide open it will not rev out in 6th but with a 52 on the rear will pull 6th and past most 250 doing it.

My '13 with RB designs carb mods and fatty runs very well . I didn't run it standard for long but this bike now has lots of power all around. The jetting is key
The change to 144 was nt a big step for me. I like the top end feel of 125 over the 144..
You could get work down to 144 to ports and head - that would possibly yield most hp
. You can still run fatty with that setup
so you could do it in stages carb , pipe , 144 , 144 with mods.


or just go straight to 165 . I had 165 but didn't do 200 pipe . You also need to run higher octane fuel or Avgas with 165 and mine was set up for Oz pump fuel and it softened the power too much for me . I ve got 165 ready to go again with DEP pipe and will re view fuel issues .... but enjoying 125 a lot

I may dyno the 125 and then 165 to do a comparison .

Main thing to do is get suspension re sprung with heavier springs all around - makes huge difference

I weigh 195-ish + gear. I went with a 6.0 rear spring and stock fork springs. I ride intermediate mx and do some offroading too. The suspension is a little harsh for true technical stuff, but works decently everywhere else and great for mx.
My '14 cr had a definite bog off the bottom stock. I used a 2004 Suzuki rm125 oem needle. I read about it on here. It almost completely eliminated the bog.
I'm running 13/51 gearing, but I may try the 13/52.

I find the 144's explosive and harder to ride off road than the 165's

especially CR 144 -

Agreed

The CR 125 bog doesn't seem to be present in WR - different needle - I like the standard WR needle - CR needle are aggressive

All due repsects to Darttypt ( darin) but standard needle works very well on newer WRs

I think they are similar in diameter of the needle which affects just off pilot power anyway - correct me in Im wrong here

The finer taper of the RM gives more fuel to mid to top

My jetting has been perfect from day 1

Running bigger main 470 to 490 - never has a bog

Hmmm I never thought about the wr needle. I didn't know there was a difference. I'm at 480 mj, 2.5 clip position, 30 pj . Just a little bit of spooge trail riding, none on a track. Starts well. Pulls long.

Great info, thanks. I found a good deal on a 52t ironman sprocket I'm going to try out. Also might play with the jetting and get the suspension revalved by WER. One of my other questions is does anyone know if it matters which cylinder (125 or 144)is bored to 165, or does it have I be the 144 cylinder?

That jetting is close to mine.
Pilot 32.5 main 470 slide nr 4 with the rm 16-62 needle at the 2 position.
Little rich on the low end but rips in the middle and top.
One issue I have is when I ride at idle speed and whack open the throttle. Then it goes mhaahhhhh and dies. Closing throttle awakes the engine again.
still have some spooge trail riding but plug looks nice brown in color
I also changed the gearing to 13-52 and am completely happy now.
Maybe a doma or fmf fatty pipe in the future

Either works Shawn

Thanks Walt, I guess I'll be slamming the 144 kit on until I'm ready to go 165. Need to do something about my buddies on ktm 200s haha

Riding a new to me 2006 wr 125 with WER suspension.- very good suspension.

A 165 shines in the bottom with a FMF fatty developed for it

Another mod highly recommended is a lectron carb (just the ease that you put in the engine with this carb is amazing and it performs on all fronts)

Robert-Jan

What is my brand new OEM 144 kit worth?

There used to be a local guy selling them for about $500 if I recall. Not sure if they're worth that anymore.

I may be interested if its for sale

always good to keep a spare cylinder

Ive got a damaged 125 one as well that would be good for a 165 conversion


I don't know if going bigger will make you any faster - only on certain tracks/trails

With the way spare parts have gone you may want to keep it.