BILLY

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Nov 27, 2001
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never mind marcus. i realized why i couldnt open them. i had to join DRN first. not a problem. i am all set now. thanks.
 

marcusgunby

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Jan 9, 2000
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dont be too disheartened look at this 03 cr125 std-makes the 04 look not too bad :)

On file of all the Cr engines back to 01, few even tuned ones make much over 30hp.A few good ones get up near 35hp but with big dips in the curve and a good 133 makes great hp but no lowend-even less than the std 04?

Heres the dyno
03 std is the low power version
01 cr133 is the top end monster
 

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bclapham

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Nov 5, 2001
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i think at this point Billy, i would be looking at the cylinder to see if there is 2mm clearance around the powervalve to see if it would take one of Erics 58mm pistons!

btw-Marcus, you are cruel!
 

BILLY

Member
Nov 27, 2001
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boy, you guys are really rubbing it in. :laugh:
i already knew that i've purchased a slug the day i picked it up. i admit it was an emotional purchase and not a rational one. but if we were all rational people here, we would having nothing to do with motocross in any way whatsoever... :)
thanks for the dyno sheet btw. the 03 stock cr looks like someone stuck a rag in the airbox as a practical joke.
the 01 cr133, to me, looks great. :thumb: i am not too concerned with finding low end in this thing because even the stocker has none. whats the use in finding some? i am going for more mid and top. thats my concern. the easy way to think you have more low end, i am sure you guys already know this, is to trick the powerband into feeling like it has a bit more by adding a tooth or two. so, after close inspection, i realized honda beat me to the punch. it already has 53 teeth on the rear. :eek:
so much for that idea. not too many 54 tooth sprockets around. btw-54 teeth is crazy, that thing would be almost the size of the rim... :laugh:
marcus, that 01 cr133, is that eric gorr's? is it on race gas, pipe, reeds, etc?
also, i hear good things about eric. would i be satisified with his 133 kits?
the 133 curve seems to be the best bang for the buck, imo. as for racing i will probably use my crf more but my heart will always be with the 2 stroke. i just want a fast cr for personal fun and enjoyment. thanks for all the great info...
 

marcusgunby

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Jan 9, 2000
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The cr133 was a EG jug, it had a v force and a 38mm carb from the 2001 Cr250.It used a DEP pipe. Cant remember much other details apart from the manifold of the v force was matched to the reed manifold.I had the top end on my bike and it pulled hard on top.

Not sure the 04 can go to 133 as the pv might not allow it-the 250 doesnt.
 

bclapham

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Nov 5, 2001
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BILLY said:
also, i hear good things about eric. would i be satisified with his 133 kits?
the 133 curve seems to be the best bang for the buck, imo. as for racing i will probably use my crf more but my heart will always be with the 2 stroke. i just want a fast cr for personal fun and enjoyment. thanks for all the great info...

Billy: at this point, i would take the cylinder off and make some measurements- you only need 1mm extra to go for the 133 kit, and if there is more room you could go for the 144 kit.

Of course, Eric Gorr is the man for this, maybe call him to see if he has seen the 04 cylinder yet and see if there is room for the mods.
 

elf

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Jun 7, 2003
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I looked over on rpms website they offer a 57mm 139cc for the 04. So there is a possibility a 58mm might work. Geez they have high prices glad I found E.G.
 

marcusgunby

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Jan 9, 2000
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RPM use a special piston for them-they are only available from RPM and cost alot.If RPM cant do a 58mm i suspect it wont fit.However Eric does a stroker kit as well-so maybe you could have a 56mm piston and 2mm more stroke.
 

BILLY

Member
Nov 27, 2001
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i'm not too interested in going into the crank for more cc's. i am mostly looking into porting and a big bore with the cylinder and head only. that is why that 133 dyno curve from marcus looks really attractive. it seems to fit the bill fine for me. i'll throw on a pipe, reeds, etc and have it ported for race gas, vp C12.
yes, rpm is sure real expensive when compared to eric... why? why is eric so cheap? i hope the guy is making money....is the quality just as good?
one question regards to the 133 dyno chart, marcus. did you ever or could you ever get rid of the flat spot at approx. 9500-10000 rpm mark?
but seeing your peak number- 37.9 - that must have been one fun bike to ride. :yeehaw:
i think i should call eric and talk to him about this kit if its available for an 04... :thumb:
you sold me.... :worship:
 

marcusgunby

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Jan 9, 2000
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The flat spot is the exhaust port is just too big-it gives good rev and top end but a dip at the point where it should be pulling.It was a fun bike to ride but i had to use 1st gear alot in corners-maybe a 54teeth would have fixed it:)

The 04 would have better low end than the 2001 as its IMO a better design.

I think Eric is at the Indy show soon.

Erics work is top notch.
 

bclapham

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Nov 5, 2001
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From what i can gather, RPMs doesnt do any 58mm kits anymore, since ive read that they refer the 57mm piston- i think the RPM piston weighs the same as a stock piston, thus, dont assume Erics 58mm wont fit in the 04. Dont forget also, Eric has plugged the PV and bored to 58mm

i will see what i can find out, Eric is on the east coast so i am sure his overheads arent nearly as outragious as they are in sunny socal. I have always been very happy with Erics stuff and he is a pleasure to deal with. Ive spoke to RPMs several times and he is also very ameanable and obviously enjoys his work and testing, locally, i have heard good things also about his work.

PS Billy: the race gas to look for is the VP Ultimate 2.....running that fuel shoud be good for maybe 1-2HP and it makes a big difference coming out of corners.
 

BILLY

Member
Nov 27, 2001
15
0
thanks guys for all the help... i will probably have to wait to talk to eric. my friend who is a parts mgr. at a local honda/yamaha dealership here in nj left yesterday for the indy show. i am sure eric's gone as well... oh well. no rush.
i am breaking in the crf this weekend. the cold temps. seemed to have broken and snow has been melting here rapidly. so, its off to the local south jersey sandpits. the 125 will just have to wait for a little while. sadly, since i already know what to expect with this cr125, i dont even want to start it, let alone ride it, until i get the mods done. :laugh:
 
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