Reliability of 144cc kit

[NM_KDX200]

I'm considering a 144cc kit for my KX125 but am curious about the reliability. I'm not looking to make a better racer as much as I'm looking to make a better recreational bike. The KX frame fits me perfectly and what I'd like is a more durable 125. As you can see from my name I have a KDX200, too. It's a great bike, but it feels considerably larger than the KX. The KX has much better suspension, and I'd rather work with it.

Suggestions?

 

[VB Racing]

I'm considering a 144cc kit for my KX125 but am curious about the reliability. I'm not looking to make a better racer as much as I'm looking to make a better recreational bike. The KX frame fits me perfectly and what I'd like is a more durable 125. As you can see from my name I have a KDX200, too. It's a great bike, but it feels considerably larger than the KX. The KX has much better suspension, and I'd rather work with it.

Suggestions?

I raced a KX144 all year, and have had NO reliabilty issues, whatsoever. I bought the bike from another dirtrider.net rider, and it has run 2 full years with no issues. I just put a top end in it(Its 2nd) and everything is within specs. Eric Gorr did the work on this bike, and I like the porting on it. It took a little time to get it tuned the way I like, but after that , I can't find fault with the motor.
All in all, I would pay to build another just like this one. :cool:


Dave

 

[NM_KDX200]

I can't find fault with the motor.
All in all, I would pay to build another just like this one. :cool:

How would you describe the motor compared to the KX125?

Also- do you have to run race gas?? That's nearly impossible for me, given my remote rural location. Best I can do is 92 octane.

 

[VB Racing]

comparison between the 2

I would say that the 144 is night and day different than the 125 stock. There is a bit more torque off the bottom, ALOT more low to midrange, and you still get decent topend. I race with pumpgas and race fuel mixed 50 50, but I could ride it wiyh pump gas only, in fact I did this spring while I was getting used to it, and doing some tuning. You can have Eric Gorr do as much or as little as you want, tell him where you want the improvement. I am very impressed with the lowend and midrange of this motor .

 

[Joshtee]

VB, was the porting on your bike for pump gas? If so, you found that 50/50 worked better for it?

 

[robwbright]

The 144 kits by E.G. have an incredible powerband compared to stock. I don't have any long term reliability experience to speak of, as I've only ridden the bike 3 or 4 times since getting it back (wintertime here).

However, dirtrider member bclapham had an 02 RM144 just like mine a couple years back. He was racing at very hilly Glen Helen every weekend and weighed 230 lbs. He was doing ring change every 5 races and piston every 10. I think he said in a previous post that he went 1 and half years of racing EVERY weekend before he had to do anything to the bottom end.

Eric designed the big bore pistons for Wiseco. If I remember correctly from what I've read here, apparently Eric's 144 piston is only grams heavier than most stock 125 pistons. . . Thus, there should be little extra stress on crank bearings, etc. . . well, except for the increase in power . . . LOL

Here's a post that should interest you:

http://www.dirtrider.net/forums3/showthread.php?t=127984

My first ride report is here:

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

My bike is even stronger now that I got the carb cleaned out and the jetting adjusted closer to perfect. When I rode the other day, I was running through the gears and hit it pretty good in 4th gear. Without any help from me the front wheel came up so fast I had to let off or I would have been on my butt . . . Granted, this was on pavement, but still . . .

If there is any way you can get race gas, I would get it - you gain about 1HP just from that. I think it can be shipped . . .

If not, you'll still have a very strong bike - I suspect your low end will be a bit weaker, tho.

 

[placelast]

Have you thought of having your 200's engine in the 125's frame? I know from personal experience it i$ expen$ive, though think of the possibilities...

 

[22703]

i had a 134cc kit done to my 01 rm125 and the yhing would rip.the only problem was the trans wouldn't stay together.i guess it had to much power so i sold it and bought a honda 250.what im getting at is just watch out for problems in the future with the tranny.especialy since suzuki and kawasaki merged as one.maybe they cured the problems of the weak trans though.anyway good luck with it you will really like the power.

 

[SirHilton17]

i have only rode 1 kdx 200... i cant see how anyone would want that motor... it is SLOW!!!

But who knows, that bike was stock, and im sure it needed a top end

 

[robwbright]

Yea - having rode my bros built KDX200 a couple years ago and my 144 now, I'd definitely take the 144 . . . even if you could put the 200 in a 125 frame.

A KTM 200 may be another story . . .

 

[robwbright]

On this topic here are the pics I have found which illustrate the difference.

Here's a 125 piston in a 144 bore:

http://community.webshots.com/mypho...5&photoID=1534778526083773316&security=WREkBY

Here's a stock 03 CR125 vs. an 01 Eric Gorr CR133

http://community.webshots.com/mypho...5&photoID=2326284960083773316&security=aFrhat

And here's an 01 Eric Gorr CR 133 vs. a stock 04 RM 125:

http://community.webshots.com/mypho...5&photoID=2209352990083773316&security=JHdsKb

The 133 is a 2mm overbore and apparently provides a quicker reving engine than a 144, with about the same peak. A 144 will have more low/mid than a 133. Unfortunately, I've been unable to find a 144 dyno. . .

 

[SirHilton17]

i have erics 134 kit in my bike.... it will haul... It is ported for mid-top, and i still have alot of bottom end... actually, still more bottom end than any other 125 i have rode....

I love my bike with the 133, and so does everyone who has rode it... i highly recomend the 133... 144 is probably even better.....

 

[yz125rider21]

good info thanks guys