Suzuki Rm 125, black oil from exhaust and breatherhose

[matzekern]

Hey everyone,

about 2 months ago I bought an 08 Rm 125. Since then I took it out for about 5 rides, and after every single ride my swingarm and brake calliper were covered in black oil. Also lots of oil out of the breather hose. It starts perfectly, and runs smooth as. No bogging or the like. I have since repacked the muffler, cleaned the air filter and regreased it. But nothing changed. I am running 30:1 mixture as it says in the manual. I believe the jetting is stock, but the muffler seems to be aftermarket without any branding though. I can't even seem to get the perfect idle. It hardly makes any difference how far out/in the airscrew is.

My bike has been sitting in the garage for three weeks now and I am getting sick of just having it sit there. Please help me!! haha

cheers :))

[Askor]

From the look of that gunk you should clean your powervalves & expansion chamber. The oil's probably pooling in the chamber and dripping out of the muffler joint. 30:1 sounds like a very high oil ratio for an RM125..should be fine on 40:1

Pull the carb, clean it, check all passageways, and double check all the jets are stock

What does the sparkplug look like?

Edit: you can see the oil dripping out of the bottom of the muffler in the first photo

[ktm84mxc]

May be a crank case seal that's allowing gear box oil to be sucked into the barrel and burnt . Very easy to spot smells like a diesel and smokes like chimney. Change the crankcase/gear box oil put in a measured amount as per the manual , after a ride drain and see if there's any loss , there shud be none . If there's a loss you have your answer.

[F5 Dave]

If the spooge is coming out the pipe it is jetting that is causing it.
Unburnt fuel will be blown out and that fuel contains oil.

Search jetting for an 08 rm125 and see what people are running.

[flashg]

Just reading your post a little more carefully. I'm thinking your crank seal could be your problem ( pressurizing the gearbox and forcing oil out breather hose) I would also expect that to affect your idle. If this is the problem I wouldn't be riding it until sorted because of being able to suck air on closed throttle and running very lean, even causing seizure,( it would be very crisp)
This is something that happened to me about 30 years ago.
I hope you get it sorted

[Yow Ling]

Do you thrash it? Might help if the exhaust temps get up a bit higher

[RGVforme]

Do you thrash it? Might help if the exhaust temps get up a bit higher

:facepalm:

[RGVforme]

Make that one more vote for a crank seal from me.

FFS don't trash it!.:weird:

Do this and you may just fuck it more.From my exp...

[husaberg]

These are Wobbly's words on crankcase leaks


EDIT - only just saw the comment - there is no such thing as an air leak lean out.
If here is a leak anywhere in the case of a 2T it will run rich, the only place a leak can cause leanness is between the carb and a reed, where extra air is sucked into the stream that already has fuel.



Simple explanation - in the case with a leak there is a much reduced compression phase caused by the piston dropping, thus this uncompressed volume in the case
doesnt assist flow into the transfers.
In the area between the carb and the reed this volume has a trap door separating it from the case during the compression phase - the reed petals.
Thus extra air is sucked in by the depression in the case when the reeds are open and this lean mixture gets all the way into the cylinder, when the reeds are closed.
With the case leak like a broken gasket or faulty seal,some reduced amount of A/F mixture makes it into the case, but very little ends up in the cylinder.
This progressively gets worse and the engine exhibits all the 4 stroking symptoms of smoke out the back etc, so of course your clever tuning buddy leans it down
and - bang - it siezes.
Hard to get your head around I know - but after 40 + years of seeing this so many times and explaining it time and again ,no one believes me.
Go try it, lift your cylinder and cut away a 1mm slot of gasket material - bolt it up and start it.
If it aint as rich as a dogs arse, then another offer of free blowys is on the table.

[RGVforme]

From the look of that gunk you should clean your powervalves & expansion chamber. The oil's probably pooling in the chamber and dripping out of the muffler joint. 30:1 sounds like a very high oil ratio for an RM125..should be fine on 40:1

Pull the carb, clean it, check all passageways, and double check all the jets are stock

What does the sparkplug look like?

Edit: you can see the oil dripping out of the bottom of the muffler in the first photo

I would start with this first then if still running shit.Do the crank oil test thing posted by ktm84mxc.

Good luck

[Yow Ling]

Make that one more vote for a crank seal from me.

FFS don't trash it!.:weird:

Do this and you may just fuck it more.From my exp...

I didnt suggest thrashing it , I asked if he does thrash it.
If you pootle round on a 2t it oozes oil out the exhaust, which is what this seems to be doing. Gear side crank seal it will be blowing loads of stinky smoke, does rm run wet stator?

[RGVforme]

I didnt suggest thrashing it , I asked if he does thrash it.
If you pootle round on a 2t it oozes oil out the exhaust, which is what this seems to be doing. Gear side crank seal it will be blowing loads of stinky smoke, does rm run wet stator?

Correct.....but.....

So say this poor guy does 'pootle' around with a stuffed crank seal all rich and lean mixing about it going on.

Reads your post "Do you thrash it? MIGHT HELP (Note suggestion here) get the exhaust temp up a bit higher".
Sounds a lot like.....If your not doing this thing try it it might help......

Thinks its him at fault not the bike takes it out and thrashes it running rich and lean pumping crankcase oil though the engine fucking it.

Pick your words wisely mate over half of what your are trying to write can be read differently by the other person unless your a top bloke that likes to write cheques for engines because the other bloke just misunderstood what you said..

Ps thrashing any engine that you have concerns about is just stupid even a 2T but esp a 2T.

[Yow Ling]

Correct.....but.....

This poor guy does 'pootle' around with a stuffed crank seal all rich and lean mixing about it going on.

Reads your post "Do you thrash it" MIGHT HELP".(Note suggestion here)..Do this thing this might help.

Thinks its him at fault not the bike takes it out and thrashes it running rich and lean pumping crankcase oil though the engine hardout fucking it.

Pick your words wisely mate over half of what your are trying to write can be read differently by the other person unless your a top bloke that likes to write cheques for engines because the other bloke just misunderstood what you said.....

please read Husabergs post re crankcase leaks, I think you could be being a bit of a nana here

[RGVforme]

please read Husabergs post re crankcase leaks, I think you could be being a bit of a nana here

Its a bit late for you to start thinking isn't it.:facepalm: lol.

Its your dollar and conscience mate.Just trying to help....Im out.

[F5 Dave]

Good, sick of your self righteous spiel.

Its an MX bike running 30:1. Not a oil pump equipped roadbike which uses heaps less oil in low throttle or low revs. Dirt bike forums are littered with these posts. Absolutely littered.

Besides the op has posted once, probably lost the URL and will never read this.

[RGVforme]

Good, sick of your self righteous spiel.

Its an MX bike running 30:1. Not a oil pump equipped roadbike which uses heaps less oil in low throttle or low revs. Dirt bike forums are littered with these posts. Absolutely littered.

Besides the op has posted once, probably lost the URL and will never read this.

Good point on the engine diffs Dave....

I was more focused on the use of bad advice in general and the outcome of that though.
Something else Dirt bike forums are littered with ive found.:rolleyes:

Let me know if the guy I hired to hold a gun to your head forcing you too read my posts is hungry.
Ill send some food over.:hug:

Calling someone self righteous is very self righteous of you lol....:killingme....I do enjoy some competition.

[Yow Ling]

Good point on the engine diffs Dave....

I was more focused on the use of bad advice in general and the outcome of that though.
Something else Dirt bike forums are littered with ive found.:rolleyes:

Let me know if the guy I hired to hold a gun to your head forcing you too read my posts is hungry.
Ill send some food over.:hug:

Calling someone self righteous is very self righteous of you lol....:killingme....I do enjoy some competition.

What a cock, the only bad advice was you telling him it was the crank seals.

[RGVforme]

What a cock, the only bad advice was you telling him it was the crank seals.

So the other two on here who suggested crank seals must also be cocks then.

Name calling the domain of the ignorant who just don't get the point.

Be sure to reply back tonight before you mum tells you to go to bed this time.You left me hanging a bit last night.:baby:

[husaberg]

Does this remind people of anyone.............:laugh:

[RGVforme]

Does this remind people of anyone.............:laugh:

Perhaps a case of learnt behavior lol....but hey if it works.....:wings:

[Kickaha]

So the other two on here who suggested crank seals must also be cocks then.:
Crank seals are piss easy to diagnose and within 5 rides it'd most likely already be toast

[F5 Dave]

I thought you said you were out of here.

[Askor]

does rm run wet stator?

No

Jeez you guys quit the bickering

Yeah I know, "this is KB" :rolleyes:

[Katman]

I'm not aware of any 2 stroke that runs a wet stator.

Why would they?

[husaberg]

I'm not aware of any 2 stroke that runs a wet stator.

Why would they?

Off the top of my head The Honda NSR125 does, as do lots of other 2 strokes.
As for the why, simply because they have the starter attached to the rotor.

[J.A.W.]

Off the top of my head The Honda NSR125 does, as do lots of other 2 strokes.
As for the why, simply because they have the starter attached to the rotor.


Some of the wee 2Ts did run a combo generator/starter, but not the RM 125, as befits being a competition MX bike..

Dunno if the 2T starter units were run as 'wet', AFAIR - most were on the the other side of the crank from the primary drive/clutch..

[Yow Ling]

RG150 and RG125FUN do as well