_j0kA_

Member
Jan 29, 2002
378
0
hey guys, i have a 2001 RM125 that had the top and bottom end rebuilt (4-5 mths ago) because it fried.. anyway, the day i got the motor back i put it in the frame and started it up (first kick i think), after about 30-40 seconds it was REALLY hot.. i could feel the heat between my knees when sitting on it.. anyway, i didnt think to much of it until i went riding.. for the first 5-10 minutes it went REALLY fast and sounded like a factory bike.. then i could smell some burning and it would start to cut out around corners or high speed straights.. sometimes i would come around a corner reallly fast on the pipe and then it would mellow out REAL bad, almost like the pv wasnt connected.. i would turn it off, let it cool down and then ride again.. i did this once and then figured something was wrong, i checked the rad fluid to make sure it was full and properly mixed, and i changed the rad cap with a friends with ahigher boiling point.. that seemed to help it run better longer, but it was still useles.. well after that i put the bike away because i was getting ready to get my 04rm250 and finally today i figured i would take it out and check it over.. first thing i did was pulled the powervalve side cover and checked to see if it was attached, it wasnt holding onto anything down inside the motor, but was attached at the top with the bolt.. i pulled the bolt off and then pulled the pv rod out to see if it wasnt just loose - sure enough it came right out.. i put it back in for now and then checked the plug (duh, should have done this before) , the procelin is pure white and the electrode has a shade of brown on it.. this to me is a lean mixture and explains why it was overheating and just recently started shooting out A LOT of white smoke - A LOT!! so what i want to know is it likely i caused a lot of damage? if not, im going to drop the needle 2 slots and see if it fixes the lean condition.. after that i want to know if the PV ROD connects to anything in the bottom case? if it does, do i just pull of the side cover - hook it up, then put it back on? i have owned the bike since oct 9/01 and was racing/practicing weekly for 2yrs and it didnt cause any problems.. i forgot to mention i moved across canada (vancouver - west coast, to toronto - east coast) and the temperatures are considerably colder now (lean).. thanks for the help, dan
 

_j0kA_

Member
Jan 29, 2002
378
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i was just checking online and one site mentions that a lean condition could be caused by leaking seals or gaskets in the motor.. this could be a possibility since this problem started after it was rebuilt... right? is it likely? i feel that it is a carburetor problem but would like others input as well..

oh yeah, there is a tiny amount of oil that comes out of the countershaft area (front sprocket).. could this be the seal that is causing the problem? thanks
 

_j0kA_

Member
Jan 29, 2002
378
0
sorry, but i have another question.. is it ok to start a cold 2 stroke and let it run for a little bit then shut it off? i mean, before it fully warms up..? just curious
 

_j0kA_

Member
Jan 29, 2002
378
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one more thing, the rear caliper on my 04RM250 wiggles a bit, is that normal? it wiggles a little on my 125, but not as much as the 250.. my friends CR125 doesnt wiggle at all..?
 

bclapham

LIFETIME SPONSOR
Nov 5, 2001
4,340
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the 2001 rm125 had a flaw with the power valve linkage rod- the rod didnt clear the governer cog and they wear right through until the PV is left with nothing to attach to- it sopunds like this has happened here.

all of this is connected to the water pump if i remember, the debris from the rod may have jammed up the impeller.

if i were you, take of the clutch cover, fit new parts to the powervalve from the 02 model (they fixed it) and then to be safe install a new water pump seal- if the water pump shaft is grooved, replace that as well- i would be cautious about the crank seal wil all that metal floating in there also.
 

_j0kA_

Member
Jan 29, 2002
378
0
thanks so much - i actually remember reading about the 01 PV failure about 2 years ago here.. i forgot to mention that i started the bike and opened the rad cap and the coolant was moving swiftly, does this mean the water pump is okay or should i check it anyway? is it safe to removed the side case cover myself or do i need certain tools to get it back together properly (i had one problem about a year ago where i bent the shifter fork assy)..

right now when i look at the rod, the very bottom looks like it has a lot of wear on it (the bottom end part)..



what can i do about the leaking seal behind the countershaft? i was planning on selling this bike so i dont want to spend money on it, but i mean i can keep it if its mechanically sound.. what do you suggest? thanks
 

bclapham

LIFETIME SPONSOR
Nov 5, 2001
4,340
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the side cover comes off with regular tools. you have three options- fix the bike properly and keep it. fix it and sell it. or leave it as is and sell it and run the risk of running into a very unhappy new owner in a couple of weeks. i suppose you could tell them it needs work and knock off some money

if the countershaft is leaking then the bearing is probable shot and cases need to be split
 

_j0kA_

Member
Jan 29, 2002
378
0
"if the countershaft is leaking then the bearing is probable shot and cases need to be split"

ouch.. even tho there is a brand new top and bottom end in there, there is still a problem? is there not just a seal behind the gear that i can replace, somewhat like the first RMZ and KXF models?

thanks for the help
 

_j0kA_

Member
Jan 29, 2002
378
0
it sounds like you know a lot about this, so in your opinion does replacing the parts/keeping it sound like a better deal then selling it (which no one will give 2 poops worth now with all the 4 strokes) ? my dad can ride it, but if its super expensive to fix im not sure what to do..
 

bclapham

LIFETIME SPONSOR
Nov 5, 2001
4,340
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i suppose you can try swapping the seal first- but often its the worn bearing that makes the seal go bad.

fwiw- a used bike like that is worthless, ive got an rm and its not worth selling. the parts arent that expensive, its the labour so thats your call
 

_j0kA_

Member
Jan 29, 2002
378
0
yeah your right.. is the bottom end something i can attempt over the winter myself? i didnt want to try it 4-5 months ago but i dont have the money to put back into labour (600 canadian).. my uncle is a machinest and can press the bearing need be.. ?
 
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