125-200cc 125 vs 144

Id like to hear an honest debate about this altough some will say there is no debate.
I have read a lot of good reports on the 144 from CH users however you dont always read bad reports as they arent as keen to post.
I do wonder if a 144 is still as fun to ride as a 125
Increased hill climbing ability is great but do the changed characteristics take away some of the fun of the top end scream of the 125?
I have heard some negative reports from YZ 144 owners about lack of revving ability possibly due to over square design and some going back to a 125.
I read about people loving the top end kick that you get from the 125 with the Mikuni carby as I do and wonder if this is lost
Any comments good or bad would be appreciated

I always was afraid that a 144 would take away from the 125 feel. I rode Joe Chod's (Now fury1's) '07 WR 144 with a EG 144 job and it was real torquey, but I didn't get to really wind it out. I liked it enough to consider doing a 144. Joe's '07 as a stock 125 really ripped. I decided to wait for the OEM 144 and I'm not dissapointed... It just feels like more all over, a super 125. It just added to the 125 experience and didn't diminish it at all.

Now for the 167 question

We’ve done 3 of these so far with a 4th nearing readiness.

1) 2006 WR125 (6 port) to EG144 (6 port) w/stock carb – First thing we noticed was a lot more punch everywhere. It was still a ‘125’ class bike. There is no additional flywheel effect or weight to change the handling characteristics of the bike. It just became more capable. This bike suddenly developed issues after about 4 hours of use that resulted in a crank seizure. There are different ideas as to why this happened, but EG replaced the piston and re-honed the cylinder. Kudos to Eric for his support on this.

2) 2008 CR125 (4 port) to EG144 (6 port) w/Kehin carb – The CR had considerably more kick than the WR to begin with but ended up just about the same as the WR with the EG144. By comparison, it gained a little less everywhere than the WR. It also lost a bit of its 'agressive' feel. The Kehin makes for easier starting (will actually start reliably in gear) but for me, appears to be a bitch to set the idle on. All in all both this and the WR were just a lot more capable without any huge change in character. BTW, this top end has 5 races and 48 hours on it and is still pulling like a bull.

3) 2009 WR125 (4 port) to OEM 144 (4 port) w/updated stock carb – We never even started the ’09 before the OEM kit and carb re-jetting went on it, so I cannot tell you the change. However, compared to the two EG144’s, it definitely has a good bit more. There is bit more on the bottom, about the same in the middle but has quite a stronger top end with a more aggressive transition from mid to top. Kind of like the stock CR125 in basic character, but just a lot more everywhere. I think that the 4 port cylinders are responsible for this harder-hitting nature. All this said, it still retains that small bike feel.

4) 2010 WR125 (4 port) – This is going to get the OEM kit. I’ve ridden it already and in stock form it most resembles the experience of riding the 2008 CR125 motor wise. I do not expect it will be very different from the ’09 after the kit goes on.

In summary then, a stock 125 is a blast to ride, a 144 is more of a blast to ride. The EG144 kit is a little softer than the OEM, especially in the mid to top transition (but I believe this to be the 6 port cylinders I used), but both are a lot stronger than the 125. All the 144s vibrate just a tad more than the 125s and will climb better, go through sand and mud better, hole-shot better and will wheelie better. What more could you want?

One more point. On the newer bikes, I find the new TMX carb to be best. It works well with the 144 and starts by just thinking about it. In gear, in neutral, with a half hearted kick….any time.

I love my 144, but I have been having issues with armpump, not quite sure if it's the increased displacement, me fighting the damper, stock zokes, bar bend or what. I raced the lochloosa enduro the other weekend and filmed it. It is very apparent from the footage that it took a little over an hour before my arm pump subsided, and my speed almost doubled.

That being said I feel they are very similar and at times one or the other has its benefits. Without a doubt you use the clutch less(144) and as stated by Kelly in his review, you are able to actually upshift while climbing hills.

The 144 stand outs in the soft stuff(sand/mud), just has more torque. I had an 07 with the old cylinder, and going to the 08+ cylinder felt like jumping onto a 144, an actual 144 has even more! I should say I've always used a 38 PWK with RB designs carb divider. Both bikes will break loose fairly easily, but it is more apparent on the 144.

The 125 felt a smidgen freer revving, but that is very negligible.

The real debate or lack thereof, is between the old and new frame/suspension. I am not by any means saying the old frame is bad(loved that bike), but the new frame is that much better. When I first rode my 09 125(now 144), I hadn't ridden in 6-7 months, I came up on a ditch fast(roughly 4.5' wide by 3-4' deep, just pinned it and held on...I survived.....in style! I don't think the out come would have been the same on the 07. Seems like you can't go wrong on the new frames, they cut harder and are more stable, the only time I think I need a damper is in rough open terrain, due to the light weight.

Good stuff - It all sounds good . I guess I dont want to lose that Nirvana feeling when you feel like you are at one with the bike - not a passenger . I dont want to lose the smoothness of the motor.
Vibration - I could live with a bit more
Arm pump - I dont get on my bike but I dont race either - a 4 stroke I do get it on..
I suppose if you are over the 180 lb naked mark it is also a big + .
The 4 port head sound better - I think mine is already 4 port as its an 08 but the 4 port may have only been done on the CR .
(The 167 debate may be best for a separate thread - I could go that way as I have the spare head - but I am concerned about keeping good top end power)
Riding ability : I think all riders of any level will gain from more down low power

Everyone is making good sense. I owned a 125wr and 144wr at the same time and I will tell you after riding and racing my 144 I hated my 125. Engine feels the same just on steroids! If I were kighter (I weigh 168) the 125 would feel ok. My experiance is with the FACTORY 144 kit and it simply works great in my opinion. Good luck

Here is the question I have been asking myself: Is the 144 kit worth the $700 dollar price tag (when converting a 125 to a 144)?

JS

$700 would be nice - where ? -
aussie $ getting stronger its getting cheaper every day!
Its 3 x the price of PWK is it 3 x the improvement ? Probably
I hope it is a big improvement - I dont notice improvements as much as some
Does it make bike easier to wheelie - without clutch?

Arm pump for me too...its the stock zokes IMO...while they are great at the big hits..its the little hits and small chop..too much comes through

I should have sent mine in a while ago...got them better with lower oil hieght...but still far from ideal...

Yes, without question.

Just put my oem 144 kit in 2008 cr125 and is better but not a 250f killer yet. I only ride motocross and keep bike at 1/2 to wide open all the time and it is a little better but not what I was hoping. I just might be the way I ride there is no bog and seems to run crisp it just seems a little better than stock 125 to me.

Do you run the standard exhaust ? maybe it needs a new pipe ? or time to loosen up?

I do run stock exhaust. What name brand would work best fmf or doma. I am still running same jetting as I was with stock 125 which does seem little rich on top but I have two more races comming up and temp in morning can be only 7-10c degress so I do not want to go to lean with colder temp. I only have about 2 hours on bike since I put 144 kit on. I heat cycle motor 3 times after I put it on then rode 2 times for 10 min slower then rode it hard after that, is that the proper way to break it in. I was surprised the kit did not come with wrist pin needle bearing so I used old one with new shaft it seemed in good shape. Also there was a little pin in powervalve case that was missing on new head and I could not get it out of old head but looks like it not needed or is it. Thanks for the help.

It takes atleast 10h before it runs great.
I did think something was wrong at my bike.

I second that. Exactly my tought. I love the top end on this bike and the crisp snappy sound from the stock CR exhaust.

I'm flat out for the next month or so but after that we'll have to organise for you to have a ride on my bike back to back with yours.

i would like that Tom - maybe in two weeks time ?
my bike with PWK and 52 rear sprocket is a tractor up hills now
It feels strong and just keeps going - just get those legs out and keep bouncing up the hill
Made it up a hill I have tried before and got stuck
I was almost thinking I dont need any more grunt
but then on twisty tracks it lacks the response for me to go fast
(You can go fast but need to be really committed)
Still have a bog to deal with at times ...
I think 08 125 with 5 port head (same as 09 ) and pWK would be much stonger down low than my old 06 was as a 125 with mikuni

I did another race on my 2008 cr 144 and it was better low to mid range power than stock 125. Did not need to slip clutch comming out of slow corners. Track was very tight in (2 to 3 rd gear )with lots of technical jumps and very hard clay, not the best for small 2 strokes with my 195 pound ass but did seem stronger down low. Next weekend racing a more open track that I can really open bike up on and see if there is much more power all around.