RMYELLOW01

Member
Mar 26, 2005
7
0
i bought a 2001 rm 125 3 years ago and when i got the bike it ran great and had good power. after almost a whole summer of riding the bike started losing power and then it came to a point where it wouldn't start and lost most of it's compression. i took it to my local dealer and they said it siezed the piston but the motor wasen't locked up. they put a new jug on it along with a top end. i got the bike fixed in march and it sat untl late april. i drained all the gas out of it and what not. i took the bike out and broke it in. the dealer said to take it easy on it through the first tank of gas and i read the maual and broke it in the way they both told me. I had gotten about 4 tanks of gas through it and i was going down a dirt road and shifted it into 6th and got to half throttle and the moter locked up and before i knew what was happening it came loose again and i pulled in the clutch trying not to cause any further damage. i stopped and the bike was hotter than it had ever been before/when i touched the pipe. soo i let the bike cool down and tried to start it but it was locked up. i took the bike home and took the head off to see if it blew a gasket but it looked good and there was no antifreeze that leaked into the cylinder or on the piston. the next morning i went out and the bike wasen't locked soo i kicked it over without starting it to see if anything sounded different. it had a clunking noise and it would lock up again, i could get it to unlock if played around with the kick. this time i took the bike apart my self to see what happened. i took the jug off and saw it was kinda scuffed up along with the piston.at tdc the rode can move up and down about a 1/4 in. the crank also turned blue on one side. the bike has a pro circuit platnum 2 pipe with a 304 somthin scilencer. if that has to do with anything . i need to know should i fix or sell it the way it is. is it worth keeping.
 

showtime586

Member
Mar 28, 2004
512
0
The pipe will ALWAYS be hot, so I'm not sure that is indicative of anything problem wise. Is there a possibility that your bikes cooling system isn't working? This would certainly cause some major problems. Did you notice any coolant spewing out of the vent tube while you were riding it?
 

kickstartkx

Mod Ban
Jun 7, 2004
62
0
what kid of oil are you mixing and what are you mixing it at? Did the bike fully warm up before you got on the thottle? but maybe your just to hard on it
 

Gazza2005au

Member
Mar 27, 2005
117
0
let me get this right did u take off the head and leave the barrel on? if so your problem could only be the piston and rings sounds to me by the conrod turning blue something caused your motor to run extremely hot and may have fryed your piston did u notice the bike bogging down while hitting the throttle shortly before the first time it happen? also your bearing would have had a spit if the conrod turned blue DO NOT try to start the bike if so u will be doing more damage pull the top end down (barrel all the way off) pull the piston off the conrod the inspect the little end bearings more than likely it was a fuel problem that caused this
 

Gazza2005au

Member
Mar 27, 2005
117
0
keep this in mind when u get to the point where your about to take off the piston get a rag or a shopping bag something like this rip a hole in the middle slide this over the piston and tape the hole around the conrod now pull the piston off so if any bearings have fallen out of the case it wont go into your bottom end
 

RMYELLOW01

Member
Mar 26, 2005
7
0
the oiston did get cooked it's scratched up bad but were the bearings wnt bad was not at the top of the rod but on the bottom where the rod connects to the crank. i was using golden spectro with a mixture of 24:1. this is what i was told by the dealer. the dealer told me to mix a 12 oz bottle with 5 gallons of gas.
 

RMYELLOW01

Member
Mar 26, 2005
7
0
what do you mean old premix. everything was fresh mixed the day it happened to me. i dunno if 24:1 is the correct ratio. what do you guys run.
 

826

Member
Mar 1, 2005
35
0
I run 32:1 of klotz. You might not have had enough lube in your engine. Or it blew because of the bearing. That is what happened in my 2001 CR 125. Now I have a 2000 YZ 250 and i run the same ratio.
 

Gazza2005au

Member
Mar 27, 2005
117
0
24:1 is to much oil being ran through your motor it will make the motor run rich and it will run hotter than normal this could be the possable cause for the melted piston also known problems with melted piston are a big gush of air and lacking fuel in the top end will melt the piston this is how i fryed my piston on my jetski it could also be a blocked carby
your bottom end bearings might have been ok but have some melted piston stopping them from moving (you hope this is the only problem) from what u have told us it'll need a new main ball,rod,top end
when a piston melts your probably ok with the sleve but it'll need a bore and hone to clean the rubbish off the sides if u want to find the cause of this pill the carby down if u find any fuel in the lines or carby pour it into a clear cup or bottle even the fuel thats in the tank once its in a clear bottle or cup take a very close look you are looking for clear jelly looking liquid ifu find some i gurantee this is the problem if not check the jets something blocked your fuel causing this problem
(if the guy u bought the bike from told u to run the bike @ 24:1 this is only for the running in process stick to 32:1 after run in)
 

Bullwinkle58

Member
Apr 23, 2004
119
0
RMYELLOW01 said:
the oiston did get cooked it's scratched up bad but were the bearings wnt bad was not at the top of the rod but on the bottom where the rod connects to the crank. i was using golden spectro with a mixture of 24:1. this is what i was told by the dealer. the dealer told me to mix a 12 oz bottle with 5 gallons of gas.

12oz of oil to 5 gallons of gas is 52:1, not 24:1. That is not enough lubrication for a 125. You should be running at least 32:1, which would be that same 12oz bottle to 3 gallons of gas.

I'm betting the crank and/or rod bearings are shot due to lack of lubrication.
 

Bullwinkle58

Member
Apr 23, 2004
119
0
Gazza2005au said:
24:1 is to much oil being ran through your motor it will make the motor run rich and it will run hotter than normal this could be the possable cause for the melted piston also known problems with melted piston are a big gush of air and lacking fuel in the top end will melt the piston this is how i fryed my piston on my jetski it could also be a blocked carby
your bottom end bearings might have been ok but have some melted piston stopping them from moving (you hope this is the only problem) from what u have told us it'll need a new main ball,rod,top end
when a piston melts your probably ok with the sleve but it'll need a bore and hone to clean the rubbish off the sides if u want to find the cause of this pill the carby down if u find any fuel in the lines or carby pour it into a clear cup or bottle even the fuel thats in the tank once its in a clear bottle or cup take a very close look you are looking for clear jelly looking liquid ifu find some i gurantee this is the problem if not check the jets something blocked your fuel causing this problem
(if the guy u bought the bike from told u to run the bike @ 24:1 this is only for the running in process stick to 32:1 after run in)

You will not hurt a 2-stroke engine by mixing your fuel with too much oil, and using more oil in the fuel will not help the break in process. A good 125 rider that bounces off the rev limiter occasionally should probably be running more oil than 32:1.
 

Gazza2005au

Member
Mar 27, 2005
117
0
us aussies (well my self) dont know the ratio in gallons so i took hes word for it @ 24:1 but 52:1 theres your problem mate thats roughly 20mls per litre when it should be 33.1mls per litre :ohmy: PM me i sill send u a fuel to oil ratio chart if u like so this problem doesnt happen again!
 

Gazza2005au

Member
Mar 27, 2005
117
0
You will not hurt a 2-stroke engine by mixing your fuel with too much oil
yes you can! and probebly will ask any good motor cycle mechanic the motor will run hotter 25:1 is the lowest u can take a two storke motor (whipper snipper,pocket bikes etc..) and it has been proven that racing two stroke motocross bikes dont run properly @ 25:1 they cough and splatter and plug will foul in no time the only time a racing two stroke mx bike should be ran at 25:1-30:1 would be running in a new motor
 

Bullwinkle58

Member
Apr 23, 2004
119
0
Gazza2005au said:
yes you can! and probebly will ask any good motor cycle mechanic the motor will run hotter 25:1 is the lowest u can take a two storke motor (whipper snipper,pocket bikes etc..) and it has been proven that racing two stroke motocross bikes dont run properly @ 25:1 they cough and splatter and plug will foul in no time the only time a racing two stroke mx bike should be ran at 25:1-30:1 would be running in a new motor

This was proven by who? If you know how to jet your bike well, you can run 18:1 if you want with no coughing, sputtering, or spooge. Yes it runs hotter (leaner/less fuel) when you use more oil, but there is more lubrication. More lubrication gives you better protection.

The guys who race shifter carts run 18:1 religiously because maximum hp is made at that mixture. More oil = more compression and more power up to about 18:1.
 

ellandoh

dismount art student
~SPONSOR~
Mi. Trail Riders
Aug 29, 2004
2,958
0
a bottle of golden spectro is what i use for my 250 it is exactly 42:1 with 4 gallons gas. i dont know the ounces in the bottle but the label explains it to be mixed w 5 gallons for regular use 4 gallons for hard duty
 

Bullwinkle58

Member
Apr 23, 2004
119
0
ellandoh said:
a bottle of golden spectro is what i use for my 250 it is exactly 42:1 with 4 gallons gas. i dont know the ounces in the bottle but the label explains it to be mixed w 5 gallons for regular use 4 gallons for hard duty

Yeah, I don't know how you're supposed to determine what "technical," "normal," or "extreme" conditions are. I ran the same stuff for years at 50:1 until I learned better. I never had an engine failure of any kind at that ratio though. I still use the same oil, but like you, at 42:1.
 

ellandoh

dismount art student
~SPONSOR~
Mi. Trail Riders
Aug 29, 2004
2,958
0
Bullwinkle58 said:
Yeah, I don't know how you're supposed to determine what "technical," "normal," or "extreme" conditions are. I ran the same stuff for years at 50:1 until I learned better. I never had an engine failure of any kind at that ratio though. I still use the same oil, but like you, at 42:1.
i like it, i did my top end this winter and i tell ya it had 100 hours at least of trails and 10 hours racing mx on a sandy track my top end was amazingly fresh i didnt even need to do it but did anyway and i didnt even need to clean the pv's. im puttin this stuff in my weedwacker snowblower and any other 2stroke i can think of

extra sweet when im at the dunes and everyone else is pouring their gas out to clean a sandy ratio cup im all mixed up w/o a grain. :)
 

ellandoh

dismount art student
~SPONSOR~
Mi. Trail Riders
Aug 29, 2004
2,958
0
yzzz said:
was there much/any carbon on the piston skirt?
or is that black stuff not called carbon?
how about the hed?

skirt looked almost new that and the head right where the plug pokes thru had some carbon like dust type stuff that would rub off with my finger
i basically tore down, checked the specs, replaced topend for the heck of it and put together
 

Micahdawg

Member
Feb 2, 2001
503
0
OMG....some of you need to get some facts straight.

What RM-Guy said below on ratios to fuel V (wrote too fast and put wrong info before)

You can not fry something by smothering the spark with a cool rush of fuel.

It sounds like your bike ran hot. Either the cooling system wasn't working, or your jetting was too lean, or your fuel was not high enough octane and preignited before it should have. When the gas ignites before it should, your timing is essentially advanced (by virtue of the combustion process occuring early) and you are left with a spike of fire from the plug hammering the piston.

Micah
 
Last edited:

RM_guy

Moderator
Damn Yankees
LIFETIME SPONSOR
Nov 21, 2000
7,045
208
North East USA
Micahdawg said:
OMG....some of you need to get some facts straight.

FIRST---- a lower premix ratio like 24:1 as opposed to 32:1 adds MORE OIL to your gas. This will provide MORE lubrication to the internals. It will also add MORE fuel to your air/fuel ratio making your bike run RICHER. ...
A lower oil ratio means for the same volume of fule/oil mixture you will have more oil and less gas which will give you a leaner burn. You will have more oil (good) but with a lean burn it will get hot (bad).

The biggest mistake people make is changing the oil ratio instead of the jetting. Pick a ratio and stick with it. Change the jetting to get it to run right.
 
Top Bottom