1998 RM125 idle issue

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Fultoncm

Member

Apr 14, 2005

87

0

• Jul 29, 2005

• #1

I finally am breaking down and asking for some advice on this. The bike just won't idle. I've cleaned the carb, changed the plug, and replaced the throttle cable. The bike runs great! It just won't idle. I have the adjustment for the cable at the grip all the way out too. I know these bikes aren't meant to idle for too long, but if I let off the throttle it just dies immediately. Oh yeah, I've played with the idle adjustment on the choke and that does squat. I can turn that thing a million times in each direction and it does nothing. What is up with that thing? Any advice would be cool. Thanks!

 

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lithium

Member

Apr 10, 2005

109

0

• Jul 29, 2005

• #2

Did you check your pilot jet and such? It might just be too lean...Also, what pre-mix are you using?
Has it ever idled before or has it been this way since you got it?

 

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Fultoncm

Member

Apr 14, 2005

87

0

• Jul 29, 2005

• Thread starter
• #3

I picked it up used and it's been this way since I got it. I have messed with that pilot jet and got it set so that is runs good from bottom end to top end. But adjusting it in any way doesn't help the idle. Is it possible I need a new top end kit? I have eben reading this forum like crazy, and the only thing I found was someone saying it needed a new piston and gaskets.

 

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lithium

Member

Apr 10, 2005

109

0

• Jul 29, 2005

• #4

Do you have any idea how many hours you've put on the bike? The only way to tell if your piston actually needs replacing is to yank off the cylinder head.....But if it runs great from bottom end to top and it has power then that's unlikley. that shouldn't be it.
I assume you've checked your float? That makes a huge difference. How many kicks does the bike start in?

 

ellandoh

dismount art student

~SPONSOR~

Mi. Trail Riders

Aug 29, 2004

2,958

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• Jul 29, 2005

• #5

find out the original stock jetting specs and see where youre at now

is it the original carb
is it hard to start
does it foul plugs
has it been ported or anything
while warmed up and running what happens when you turn on the choke
what plug are you using

 

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Fultoncm

Member

Apr 14, 2005

87

0

• Jul 29, 2005

• Thread starter
• #6

The engine is all stock. I checked the float and it's all good there. I went by the measurement in the manual to ensure it's floating at the right level.

It's not hard to start at all, one kick...maybe two. It starts right up, and when it stalls from not idling, it'll start right back up no problem. Should that idle adjustment on the choke knob do anything? It doesn't seem to be doing anything for me.

I haven't tried turning on the choke when it's warm and running. I'll try that tonight when I'm out riding and see what happens.

I am using the stock plug and jsut recently picked up a bunch of new ones from the Suzuki dealer.

 

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Fultoncm

Member

Apr 14, 2005

87

0

• Aug 1, 2005

• Thread starter
• #7

I think I may have found the problem. The bike has an FMF Fatty gold series and spark arrestor. I pulled the carb off, for the 5th time, and checked all the numbers on the jets. Nothng matches what FMF recommends on their site, and the jets aren't factory spec's. Should I go by what FMF says? That would mean getting a smaller main jet, which would lean out the mixture. I think this might mess up my wide open throttle. Right now it does bog a little when full throttled.

or should I just ditch this pipe, get the OEM and put the carb back to spec? that sounds crazy.

 

L

lithium

Member

Apr 10, 2005

109

0

• Aug 1, 2005

• #8

Hmm...i Have a Fatty pipe on mine, but i never re jetted because i thought everything was running ok. If you knew someone with the same bike you could yank off their oem just for experiment. But maybe try going with what Fmf says...If you switched back to OEM pipes..it really wouldnt make that big of a difference.

 

ellandoh

dismount art student

~SPONSOR~

Mi. Trail Riders

Aug 29, 2004

2,958

0

• Aug 1, 2005

• #9

start fresh from stock settings, more than likely youll have to lean things out a little ........fmf stats are crap , i think they just put those up to say they did. for my bike they posted a half arse copy of what mxa put up for my bike in stock form.

 

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Fultoncm

Member

Apr 14, 2005

87

0

• Aug 1, 2005

• Thread starter
• #10

I think I may have discovered the problem with the idle. I wasn't turning the idle/choke knob enough.

I think ellandoh is right on FMF specs for jetting. I am going to bump up my main jet from 170 to 172 to see if that helps my top end. It's just flatting out slightly and I'm hoping that riching it up a bit will help. I can get all the jets I need to go back to spec, but it seems the jet needle is going to be impossible to find. We'll see what happens this weekend.

 

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rpmRMiam

Member

Jul 7, 2005

25

0

• Aug 2, 2005

• #11

170 main 50 pilot stock needle 4th groove from top. remove sparky,clean with gumout,replace.....clean ur air filter....keep us posted...Email me if you want my number so we can sort your bike out. goodluck. ;)