rm125 won't start...

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02rm125

Member

Mar 15, 2006

26

0

• May 7, 2006

• #1

I was riding at our track this afternoon and i noticed my bike wouldn't stay running at idle. It also seemed to be bogging out a lot. I figured no big deal, i'd tune the idle mixture when i got home. But then after a few laps I ended up laying the bike over in a corner and when I picked it up again and tried to start it, it wouldnt start. After that I loaded it up and took it home, changed the plug, and it still wouldnt start....Any idea what the problem could be???

 

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robace78

Member

Apr 28, 2006

24

0

• May 8, 2006

• #2

my friend has the same bike and had the same problem. Check the compression. If it is low then pour like a table spoon of motor oil down the spark plug hole. Test the compression again. If it almost doubles then you have a bad piston ring. He just went ahead and replaced the whole piston. Put it all back together and started in 3 kicks. NOTE.... if your going to do this I would advise draining the coolant and motor oil. We just completed this project and had to end up finding out the hard way. Anyways if you have good compression it is most likely the reeds. Good Luck!!!

 

robwbright

Member

Apr 8, 2005

2,283

0

• May 8, 2006

• #3

I assume the jetting was alright before . . .?

 

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02rm125

Member

Mar 15, 2006

26

0

• May 8, 2006

• Thread starter
• #4

yes, the bike has ran great since i bought it last june....until yesterday

 

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robace78

Member

Apr 28, 2006

24

0

• May 8, 2006

• #5

I'm tellin' you.. test your compression.. it's simple to do. You can buy a tool that screws in where your spark plug does. Turn the gas off. Give it full throttle and kick it like five times. See what your compression is. I believe on your bike it should be around 165. If it's not and it's under 100 or around 100 pour just a little oil down the spark plug hole and do the test again. If it doubles you have a bad piston ring. You can fix it yourself in a day with your manual. It's simple to do just a lot of taking apart of things. Have a friend help you it will go quicker.

 

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02rm125

Member

Mar 15, 2006

26

0

• May 8, 2006

• Thread starter
• #6

alright i'll do that....thanks for the help

 

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02rm125

Member

Mar 15, 2006

26

0

• May 9, 2006

• Thread starter
• #7

ya i checked the compression yesterday....it was at 80 psi haha...im assuming i need a new top end??

 

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robace78

Member

Apr 28, 2006

24

0

• May 9, 2006

• #8

exact same problem my buddy had... did you pour a little motor oil down the spark plug hole then test it again??? You should get double the compression because the oil will seal it for a minute... but yes it does sound like you need a new top end... you can do it yourself for way cheap... if you take it in they will charge you a boat load for labor!!! hope you get it straightened out soon!! peace YO!!!

 

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02rm125

Member

Mar 15, 2006

26

0

• May 9, 2006

• Thread starter
• #9

yep i did pour some oil in the spark plug hole and it put me at about 150 psi.....

and i just ordered a new top end...i looked at my service manual and it doesnt seem like it'd be very hard to do...it'd just take some time to take everything apart and put it back together. So ya...hopefully i'll have it runnin again by this weekend

 

robwbright

Member

Apr 8, 2005

2,283

0

• May 9, 2006

• #10

02rm125 said:

i looked at my service manual and it doesnt seem like it'd be very hard to do...

Click to expand...

It's not very difficult. Just pay attention when you take it apart.

 

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robace78

Member

Apr 28, 2006

24

0

• May 9, 2006

• #11

let me know how it turns out bro... hey a little advice. drain the coolant. drain the oil.... you will experience problems later on if you don't... we just put a new top end in last weekend. and don't forget to flush your radiator with fresh water after you drain it... cool man good luck!!!!

 

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02rm125

Member

Mar 15, 2006

26

0

• May 9, 2006

• Thread starter
• #12

thanks guys...i'll be sure to ask ya if i have any problems installing it

 

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02rm125

Member

Mar 15, 2006

26

0

• May 9, 2006

• Thread starter
• #13

oh and when i flush the radiator, should i use distilled water or will tap water work ok???

 

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2-strokes-4-life

Member

Mar 1, 2005

231

0

• May 9, 2006

• #14

you can flush it with a garden hose,but when you fill it back up use distilled water

 

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02rm125

Member

Mar 15, 2006

26

0

• May 15, 2006

• Thread starter
• #15

I got the new top end in it on saturday, it was a piece of cake, just a lot of taking apart and putting back together. Now it runs better than it did when i first bought it!!!!!! Lets hope it lasts for a while...