hoov165x

Member
May 31, 2002
106
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My version of the ultimate vet bike would be a KTM 200 motor in a CR 125 Frame. This will probably not be possible anytime soon, so I need advice on the useability of big bore kits. Wondering if anyone out there can tell me if the CR 144's have anywhere near the bottom end power of a KTM 200 while maintaining the stock high RPM power. As you can see I am a lazy 250 rider that wants to have his cake and eat it too!
 

Jman271

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Oct 18, 2001
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In the back of the dirt bike mag ad's everybody and their brother has kits avavilable for CR's. I don't know for first hand exp, but from what I have heard the Eric Gorr 133 w/ port job, w/ pipe/silencer is hard to beat.
 

robj

Member
Oct 31, 2000
71
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On the quest of the ultimate woods bike: can the 2002 CR cylinder/power valves be modified to expand the capacity to 150cc plus? I thought I heard about 167 conversions. Would you need a different ignition pattern to create a linear power delivery? Also are there compatible Honda gears to create a longer 5th? How about flywheel weights and lighting? Thanks for any info...
 

imlostagain

Member
Feb 12, 2002
91
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I believe the 167 is a stroker motor costling upwards of $1800. I too read the cylinders can only go to a 133 bore. I have a '99 CR144 and am very pleased with the power compared stock. The motor has considerably more low-end and brings on the power more similar to a 250 than a 125. Unfortunately , I haven't compared my bike to a KTM 200 but I wouldn't hesitate to go the overbore route especially considering Eric Gorr has VERY reasonable rates on his work . Hope this helps ...
 

marcusgunby

LIFETIME SPONSOR
Jan 9, 2000
6,450
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If you really want a 144 you need to get a 99 top end complete with actuator arm for the powervalve and you will need to be able to fabricate the exhaust manifold.I wouldnt go for a stroker 125 as they make weird power from the dyno charts ive seen.
 

DEANSFASTWAY

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May 16, 2002
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Ive made them 154 but you have to weld up the cylinder and plug up the exhaust ports . There in some micro sprints out here , they kill the new RS motor . Were using a dome piston but are working on the flattop setup. Theyrip.
 

MX Madman

Member
Oct 7, 2000
31
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My son races a 98 E.Gorr 144,with the "Mo Better Everywhere"porting and a 250 airboot.....This thing rips for a 125.Great bottom,and more mid than I thought you could get from a moter this size.And the topend rev`s great. :cool: I currently race a 96 cr250,but would be very happy racing this bike.I have been thinking racing it in the Vet+30 to see how it would do. :D
 
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NO HAND

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Jun 21, 2000
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Originally posted by Jman271
In the back of the dirt bike mag ad's everybody and their brother has kits avavilable for CR's. I don't know for first hand exp, but from what I have heard the Eric Gorr 133 w/ port job, w/ pipe/silencer is hard to beat.
I agree with that too. I've had the chance to experiment with different carbs, airboots and reed cage. My conclusion is the 133 kit is responsible for the increase in power while the rest of the bolt-on mods only send the powerband higher or lower. I ended up liking best the 133 kit with everything else stock. See for yourself what mods you like best on your bike but it's safe to say the 133 kit is the place to start.
 

bclapham

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Nov 5, 2001
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i was cruising eric gorr's website and he has a full 99 cr150 big bore kit for sale, maybe this is the answer to you needs, if you want to go the extra mile with the modifications!
 

placelast

Member
Apr 11, 2001
1,298
1
Although I'm happy with my 250 for what I do - enduros & general trail riding - I like the idea of a 200 but don't think they've been perfected yet, therefore the idea of an overbored 125 is awfully appealing.

There is a Husky shop nearby that uses a German-made Mahle piston (same company who does the same for euro formula cars) to punch out a WR/CR (as in Husky)125 to 167cc's! That's the max overbore on a 125 I've ever heard of. No crank work needed either. It's expensive @ $4-500 but sure tempting.

If you go to the Husky web site, look for the one in Santa Ana, CA called UpTite.
 

*william*

Member
Jul 5, 2000
344
0
Originally posted by placelast
I like the idea of a 200 but don't think they've been perfected yet...

WHAT? :scream:

Lastplace, next time we meet up for a Crew™ shindig or a D37 race you'll have to ride my 200EXC. I've got it jetted to a T now, and this summer I'm getting my suspension done and hopefully a stabilizer too - if I have any money left. I can't think of a better bike for guys our size. It nice and tight like a 125 and almost has the power of a 250. I'm regularly hosing guys on 250's, open's and big strokers down the bomb run in the scrambles and H&H's. And when the course gets tight through the rocks, I just wait for the big bikes to stall and then I cruise on by. Life is good. :cool:
 

DEANSFASTWAY

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May 16, 2002
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PLACELAST I think were talking about a HONDA CR125. What are they doing to keep the HUSKY cranks together. In 97 98 I worked ayt a shop (who shall remain nameless) and we must have done cranks on a;most all the 125s we sold . HUSKY USA rep said you gotta run leaded fuel in those bikes (what a joke) In the GPs dont they run unleaded. 144 154 HUSKY CR gotta rip though . If only you could get the clutch to last longer , maybe with more power less clutch abuse is needed . JUST CURIOUS ?
 

DEANSFASTWAY

LIFETIME SPONSOR
May 16, 2002
1,192
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Ill bet if someone started a serious 200cc MX class it would probably be the most popular. Less maintenance neede than 125s and less injuries due to less power than radical 250s . But there are already too many classes now. ENGLISHTOWN NJ RACEWAY PARK has about 44 motos and they dont race guads . Its a long day . CHEERS
 

*william*

Member
Jul 5, 2000
344
0
Originally posted by DEANSFASTWAY
Ill bet if someone started a serious 200cc MX class it would probably be the most popular.

KTM's is coming out with a 200SX for 03. It would be killer in our D37 classes like Vet and Senior where it's 0-250cc's.
 

nos96

Member
Jun 3, 2002
39
0
So now you all have me very interested in a big bore kit for my 99 CR125. Sounds like the 144 is the way to go for me. I am curious however, will doing so ever make top end rebuilding more complicated??? And what else must be or should be done (porting&what not) on the rest of the engine?
 

NO HAND

~SPONSOR~
Jun 21, 2000
1,198
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Originally posted by nos96
So now you all have me very interested in a big bore kit for my 99 CR125. Sounds like the 144 is the way to go for me. I am curious however, will doing so ever make top end rebuilding more complicated??? And what else must be or should be done (porting&what not) on the rest of the engine?
Top end rebuilding is no different than before. The only difference is you have to know what Wiseco piston number to order because it is different than stock. But, the pistons are just as easy to find. The tuner you choose will supply you with the part number you need. I know Eric Gorr from Forward Motion supplies the porting along with the big bore kit. I don't know about the others. Forward Motion has good prices and a reputation that is hard to beat. The one thing you will run into is jetting change. If you can't afford to spend time re-jetting with your new cylinder, you just can't afford the big bore kit.
 
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Dec 22, 2016
3
0
How about a 2003 CR 125 chassis with a 2003 KTM 200 SX mill. Maybe the Brown Brothers could shoehorn the motor in?
On the quest of the ultimate woods bike: can the 2002 CR cylinder/power valves be modified to expand the capacity to 150cc plus? I thought I heard about 167 conversions. Would you need a different ignition pattern to create a linear power delivery? Also are there compatible Honda gears to create a longer 5th? How about flywheel weights and lighting? Thanks for any info...
 
Dec 22, 2016
3
0
I believe the 167 is a stroker motor costling upwards of $1800. I too read the cylinders can only go to a 133 bore. I have a '99 CR144 and am very pleased with the power compared stock. The motor has considerably more low-end and brings on the power more similar to a 250 than a 125. Unfortunately , I haven't compared my bike to a KTM 200 but I wouldn't hesitate to go the overbore route especially considering Eric Gorr has VERY reasonable rates on his work . Hope this helps ...
 
Dec 22, 2016
3
0
I have the original honda 125 modified to 167, had cylinder leakind problems because of bad welds in the power valve area. This is a big task with the honda, yamaha is much easier. The bike is a 1999, bored carb, stroked and uses a yamaha 250 pistin, the head seal is modified for o ring. Handles like a 125 with 250 power. Awsom. I have built 144 hondas and bore and stroke is changed with some metal removed from power valve.
 

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