03 RM125 vibration

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Oct 21, 2000
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#1
I picked up an 03 RM125 recently and there is much more vibration than with my 00 KX250. Is this normal with the RM125?
 
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#3
Thanks for the reply, Marcus. That isn't what I thought I would hear. I've heard about the $40 sparkplug that's needed because of the vibration, so I thought this must be normal. I feel the vibration through the footpegs and the bar. Makes my throttle arm give out too soon.

I bought the bike new - a non-USA model - still in the crate. I've changed the jetting to the USA specs and the bike is much faster that I thought a 125cc would be. I'm running VP C-12 and judging by the amount of spooge dripping from the silencer I'm still rich.

I'll go over the bike and torque all the bolts and report back. Let me know if there's anything else I should check.
 

marcusgunby

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#4
Thats weird it vibrates that bad from new-
a better jetting is
pilot 35
AS 1.5 turns out
needle 2nd clip from top
main 490-460.

i fill my bars with RTV to tame the buzz.

On the vibes i rode a 2000 KX and it vibes hard compared to any 125-the only thing im wondering about is the type of vibes you are feeling-maybe they are a higher freq as most 125s do buzz more than vibe.
 
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#5
You're right - it is more of a buzz. I thought my KX vibrated a lot at first but now I don't notice it at all. Maybe I just need to put some more track time in and see if I get past it.

I really need to go over the bike and make sure the bolts are tight. I'll get to that this weekend.

I'm mostly concerned about my throttle hand. I wonder how much a Pro-Taper bar with RTV and RG3 triple clamp would help? Those solid-mounted bar holders can't be helping.

Thanks for the jetting help. The vibration on my son's KX85 lessened noticeably when I leaned the jetting. Maybe that's part of my problem. I'm still dripping a lot of spooge and I'm running:

Gas: VP C-12 mixed 40:1 with Yamalube 2-R
Main: 460
Needle: non-USA needle that's 1/2 clip richer than USA needle, with the clip 2nd from top - which puts it 1/2 clip leaner than USA-stock
Pilot: Stock (I think it's a 45)
AS: 2 1/2 turns, I need a smaller pilot

I know I need to lean something. The pilot's a no brainer. After that, I guess it's just trial and error with the main and clip.

Thanks again! Mark
 
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#6
I'm running 37.5 pilot, needle in the second and 440 main in Austin TX 700 feet about see lever about 80-90 deg, pump gas with 32:1 suzuki oil.
 
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#7
RM125 Vibrations

I picked up an 02' RM125 a few weeks ago and it vibrates more than my 2000' YZ125. I thought that the main bearings were going bad, so i replaced them. It still vibrates a lot more than my YZ. Is this just inherent in the newer RM125's now?