Son is thinking of selling his 250F and getting a 144 kitted 125.

[karterron]

A little history, son grew up on 2 strokes with 80's and 85's. Missed a couple years of riding and we got back into the sport last fall. Bought two KX250F's for him and myself. I rode mine once and got rid of it and went back to the 250 two strokes I always had.

My son has ridden his several times and somewhat likes it, but then jumped on my 250 and fell back in love with 2 strokes. He likes how much easier it is to jump and the extra power. He has yet to get used to the engine braking and vibration on the four strokes. Plus he is worried about that big overhaul bill he has coming in a couple years.

Today he was asking me what a big bore 125 would run like. He has ridden a friends CR125 and it just doesn't have the power.

For some of you that have the 144, tell me what they feel like compared to a 125, 250F, and 250 two strokes. I don't think he is ready for a 250 even though that's what he wants. But I told him I'm not comfortable with him going from an 85, missing two year, riding a 250F about 6 times and jumping on a 250 two stroke. Plus, he won't be able to race with his friends like he does now.

Any advice on what to do?

 

[berudd]

From what I have heard the 144 still does not have the power of a 250F. At least not with the broad spread. I recently read a CR144 build and they said the power was in a very narrow band. But the CR125 is no fire breather so maybe another 125 would be better. I have thought about it with my KX125. Maybe a 125 with a pipe and VForce reed block would be a first step.

Vibration? Most 2 srokes I have ridden vibrate much more than a 250F.

Rebuild? The newer bikes are become more reliable and I don't think it is a foregone conclusion that you have to replace everything all that often. Piston life is much better than a 125 for sure. If you keep the vavles in spec they will last quite a while.

I don't think you should expect to turn a 144 is to a 250F killer. I may be fun to ride but I still think the performance edge goes to the 250F

 

[MXP1MP]

I disagree first off that article your referring to is from dirt rider from a couple months ago they bored n stroked the bike and it was done by max power. I read that article and it would of been better served up as toilet paper. I'll post tonight when not at work how I like my '06 YZ 144 EG modded for me pulling guys on 250F's n up with it has been a blast especially up horsepower hill at washougal, I can typcially pull like a bike length n half on my friend with an '06 CR 125 easy! Even it we start dead even on the pipe. He's jealous as all hell right now.

 

[karterron]

Don't kid yourself into thinking these 4 strokes don't have a big bill for rebuild. Yes they do last, that's why I said big bill in a couple of years, but when that bill comes due it's sometimes 1/2 or more than the whole bike is worth. That's not the case with a two stroke. Unless you have a catstophic failure from stupidy or a very old bike, you will never get a bill that is 1/2 the value of the bike.

We're not looking for a 250F killer, he doesn't race. What we want is the torque and lugging ability a 250 two stroke has in the lighter chassis of the 125. I just got off the phone with Eric Gorr and it sounds like this may be the way to go. Eric said his full on YZ144 is only about 5-7 hp less than a stock 250 two stroke. My son likes the feel of two strokes, he just wants more power than the 125 has.

I'll see what others think and do some more research, but it looks like this may be a good option. I'm sure I'll get some questions on why we are selling an 05 250F to buy a 125.

 

[robwbright]

It is difficult to compare the 144 to my old stock 125 (or any other 125 I've ridden - I haven't been on one of those monster 2006 KTM's or YZ's). There is no comparison. The stock 125 had maybe 30-32 HP peak. A stock 250f is maybe 30-33 HP peak. The 144s vary from 36-39.5HP peak depending on the tuning. My guess would be that I gained 20% HP pretty much everywhere.

Eric Gorr has a very good reputation for the 144s, but he's not doing work until fall. He did my whole kit, including piston, ring and reassembly for $450. I think it was $475 before he went to England to work for the summer. I had "mo betta everywhere" porting and high compression (14.5:1) for race fuel.

I will post links to my initial impression and other stuff below.

You can also take a look at the "Do 144s compete with 250f's thread" - but beware - it gets kind of messy in there. ;)

I recently was able to ride several laps on my 144, a 2006 KX250f and a 2006 YZ450f back to back to back on my practice track. Hard pack with soft sandy berms.

The 144 made me feel like I was going faster. ;) I think that is a result of the sound of the 2 stroke and the fact that you're working harder. If I got off in the soft stuff in the corners, the sand caused much more wheelspin than the 250f and robbed my power. The 144 handled better and I felt more comfortable - but then again, it is my bike. I would say that I had more fun exiting corners (when I hit them right) on the 144 because of the hard hit.

The 250f was easier to ride fast - less shifting, and it didn't matter as much which line you took in the corners. I guess the best way to describe the 250f was "less concentration required." It was easier for me to get up speed to clear jumps very close to the corner exit - but I was able to clear anything on the track on either bike. The 250f felt tall and a bit top heavy, but we knew that already. . .

I think that for the first 5-10 laps, my times would be very close. I am quite sure that I would get progressively faster on the 250f as I got tired. However, the races I run are typically only 5 laps, so that's not really an issue. If they were 15 laps, it would be a different story.

As to a 250 2 stroke - I don't think you're going to make a small bore feel like that, but since a stock 250 has maybe 43-46 HP, the possible 38 or 39 HP of a modded 144 is getting pretty close as far as peak - especially given the weight difference.

First Ride Report:
http://www.dirtrider.net/forums3/showthread.php?t=126800

Reliability:
http://www.dirtrider.net/forums3/showthread.php?t=124121

Race Report:
http://www.dirtrider.net/forums3/showthread.php?t=133418

 

[robwbright]

read that article and it would of been better served up as toilet paper.

Yep. The Dirt Rider guys don't seem to understand anything since they had it stroked. As I understand the new 144 rule, it only allows boring - not stroking. Thus, their 144 is not even legal in the 125 class - and they stated that it was.

The description they gave of their 144 was NOTHING like mine. Their's had numerous "bogs" in the powerband. Mine has none.

BTW, my 144 revs better than the stocker.

 

[CR2FIFTYR]

I would say just get him a cheap 250 by the sounds.I am 15 now and last summer I had a 1979 kx250 and never got hurt once and now I have a 1995 cr250r and i only got hurt once because I was riding it with a flat bald tire and rim with bent spokes which does no good and I hit a jump in first endoed and went over the bars.unless he is like 11 or younger I say a lower 250 2 stroke is the way to go.

 

[steve125]

We're not looking for a 250F killer, he doesn't race. What we want is the torque and lugging ability a 250 two stroke has in the lighter chassis of the 125. QUOTE]

The 144 wont do that, at least if you have it tuned so it revs decently.

I own both, a mod 250F and a 144. The mod 250F is much closer to what it sounds like you want, at least motor wise. The 144 is awesome, but it still runs like a 125, a very powerful pro level 125.

The 144 will make your son a better rider as it requires much more skill to ride it fast. The mod 250F is cake to ride, and much more forgiving, simular to a 250 2 smoke but easier to control.

 

[John Cena]

How about a 250 2T with a flywheel weight added?

 

[muddy226]

Have you thought about a KTM 200 ? I've never ridden one, but from what I've seen at the practise tracks they seem pretty good, though I've never seen one race as they don't seem to fit into any of our classes.

 

[john3_16]

Piston life is much better than a 125 for sure.

Are you sure about that ?

 

[karterron]

John

He already loves the power on the 250 stroke, don't need to tame it. He wants a 250 2t, it's me that is a little nervous that he's not ready for it. Although at 16, he is bigger than me so I'm probably just the worried father since he really doesn't ride above his ability. I was thinking the 144 might be a good mixture, more my idea than his.

I totally forgot about the KTM200. That's actually a good idea. Although, I think they are pretty scarce so I'm not sure how doable that would be. If we sell his 250F we are going to need to have a bike in mind ready to go right away.

 

[karterron]

We're not looking for a 250F killer, he doesn't race. What we want is the torque and lugging ability a 250 two stroke has in the lighter chassis of the 125. QUOTE]

The 144 wont do that, at least if you have it tuned so it revs decently.

I own both, a mod 250F and a 144. The mod 250F is much closer to what it sounds like you want, at least motor wise. The 144 is awesome, but it still runs like a 125, a very powerful pro level 125.

The 144 will make your son a better rider as it requires much more skill to ride it fast. The mod 250F is cake to ride, and much more forgiving, simular to a 250 2 smoke but easier to control.

Thanks Steve. I agree with your 4 stroke comparison. After he liked my 250 so much he rode a buddies RMZ450 back to back to the RM250 and said the 450 felt slower.

I'm going to have to give them some thought. He wants a 250 2t, so I may end up that route if that's what he really wants to do. I'll just wait a month and watch how he rides and handle my RM250. If he shows me he can handle it, I will sell the 250F and get him the 250 2 stroke.

I was hoping the 144 had similar torque to the RM250. Sounds like it's still a revver like a 125, just a lot faster. That KTM 200 is a good idea and I'll have to see what is for sale locally.

 

[MXP1MP]

No the 144 doesn't have quite the same torque it's more like a 200 but don't forget things like porting make a difference and I had mine ported for mid/top I don't deny that it is not a 125. But part of what makes it so much fun to ride is how high it rev's up.

If he's a big as you say he is then maybe you should really consider the 250, I think he's shown you he can ride one. Besides what happens if you go the 144 doesn't like after a year etc money wise the 250 will be cheaper, hell just get another RM and you'll have common parts you can just swap.