slapshot1540

Member
Jul 27, 2008
53
0
ive got a 2000 cr125 i bought from a guy who polished the intake ports and put a fmf pipe on it and thats all he did 2 it. i dont think its gettin full bottom end power it wont idle it wont really wheelie in first gear it jus seems 2 bog down then it gets 2 going after that i was told it could be the reed valve or i could b suckin in air underneath tha jug or i could b suckin in air inta tha left or rite of the crankcase so i tested all of this and everthing wuz fine i also tesed tha compression which wuz a little week so i rebuilt the top end thinkin that would solve the problem but its basically tha same....im jus thankin that bcuz he polished the intake ports it jus lost the bottom end power and theres nuthin i can do about it but would it be carb jetting or different sparkplugs?? or im thinkin bout puttin a torque spacer in?? please help
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
Slapshot, slow down, breathe, and write sentences for starters. Its very difficult to decipher! If your cylinder has been "eye candy ported" by "fools with tools" It is more than likely ruined. I can only hope they did not take a dremel tool to the cases! More than likely this is why your engine will never jet/run correctly. Been there, done that. Lucky for you, that model can still get oem cylinders.
 

yzwoods

Member
Aug 2, 2006
39
0
With the mod of the pipe it sounds like your jetting is off.
Your pilot jet and needle will be the issue. FMF has recomended jet setting for there pipes. What alttitude are you running at and what jetting. The CR can be a pain to jet at times and if it was not adjusted accordingly for the mod then that could very well be the prob.
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
yzwoods said:
This is a simple fix before you break out the wrenches. Also what mix are you using?
Step 1, put back on all the metal that got removed. Step 2, re-texture everywhere that erroneously got polished. Then it will be easy, and the bottom end will find its way back.
 

yzwoods

Member
Aug 2, 2006
39
0
What does that mean?With the mod of the pipe it sounds like your jetting is off.
Your pilot jet and needle will be the issue. FMF has recomended jet setting for there pipes. What alttitude are you running at and what jetting. The CR can be a pain to jet at times and if it was not adjusted accordingly for the mod then that could very well be the prob.

This was my orig post. Do you disagree?
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
"ive got a 2000 cr125 i bought from a guy who polished the intake ports", The first part of the sentence. The cylinder is pretty much scrap. I have no idea what the exact volume and angles was. Neither does the person who polished it. The volume and flow has been changed. Did this person run his mod thru a reputable software simulation first? If he did he would have known better than destroying the exiting textures by polishing. That ruff cast is real close to the optimum surface texture. Even if you knife the transfers, that material needs to be put back somewhere else.
 

slapshot1540

Member
Jul 27, 2008
53
0
ya i may rejet it. but if it needs a new cylinder i may jus forget it and ride with it. and ive heard bout ruffin it up. it looks like the guy took a dremel 2 it tho. im using 32:1 93 octane that sound ok?
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
The ratio and gas are fine. I have no idea about the amsoil thing? I could think of 5 oils I would jump on before amsoil, or klotz! If they paid me to use it, I would probably find something else to dump it in. I would feel bad selling it to you! Half price!
 
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