02 KTM 125sx (Exhaust Smoking Excessively)help please?

so I have a ktm 125sx that is having some major smoke and splooge coming out of my pipe.

Not soo sure on were I should began looking and weaving out what worked and what didn't?

Any advice and help on my issue would be a great start for me.

the smoke is really heavy and white,has a smell to it but im not sure if I can pin that its tran fluid.

 

I run honda's, but symptoms would be the same with issues. Heavy smoke would either be tranny fluid, or coolant. Does the smoke smell a little sweet? Coolant being burnt tends to have a sort of sweet smell to it. The tranny fluid will smell different than premix, more like a vehicle burning oil. Coolant level down? You can drain the tranny, and add the exact amount of fluid it calls for , and ride it, and re drain and measure. It should be very close or exactly what you filled. I'd suggest a leakdown test. You can build a leakdown tester pretty cheap, depending on whats available for parts locally. Many build them with about 20 bucks. Me, I had to shop around more, and pay more with less stores around. I have about 50 in mine, from lowes, welding supply shops, etc.

Its an old bike, it probably just needs a re-build... It could be a variety of things from lack of compression to carburetor issues and blown seals. I've seen things like this happen when the seal going into the right side crank case fails and it sucks up oil from the gearbox into the combustion chamber. Again, its an 02', all the rubber seals and gaskets are long since worn out and corroded, so its so hard to pinpoint exactly the issue without re-building first.

so I have a ktm 125sx that is having some major smoke and splooge coming out of my pipe.

Not soo sure on were I should began looking and weaving out what worked and what didn't?

Any advice and help on my issue would be a great start for me.

the smoke is really heavy and white,has a smell to it but im not sure if I can pin that its tran fluid.

If your not noticing a loss in trans fluid (which indicates a blown crank seal), then the only other "spooge" culprit is overly rich jetting, or you have adequate jetting and you need to get harder on the gas and burn off some carbon.

It could also be worn rings. Agree that some testing is in order. A compression or leakdown test would be a good idea.

 

Whats the bike worth to you? Can you afford the worst case scenario of a blown crank seal?  And if doing crank seals, what about doing the crank and bearings?

 

I just picked up a 2000 125 EXC that smokes a bit too. I bought a Namua ring for $8 and a complete gasket kit for $15. I'll do the ring first, then repack the silencer to start with a clean slate. After a ride to evaluate, I'll consider some jetting changes. Crank seals will be at the bottom of the list.

Looking to find out more about this leak down test and how to build one,yet use one correctly,

Also if I'm on there replacing the right side crank seal then what about the main bearing does that mean I will need my cases split?

 

 

Its an old bike,

I dont see any info about the yr of the bike. You know something that the rest of us dont? Old is relative, too.

 

A "LEAKDOWN" test on a 2 stroke is overkill given the simplicity of this motor. A leakdown test would be more for a 4 stroke. If anything, a compression test would be the proper test. You can spend $$$ on various tools if you want. Or you can save said  bucks on the tools, and spend the coin on replacement parts. Covering the basics with a fresh top end is the 1st step. An online search will reveal free service manuals to help you.

 

I am in a similar position as the OP, having just picked up a 2000 KTM 125 EXC for my son. We just did a ring replacement ($8 for a NAMURA ring, $22 for a top end gasket set. The piston was within spec. Now its time to adjust the jetting and repack the silencer. The main is a 180, which seems quite fat. We will try a 175 and see how it goes.

 

Op, what premix are you useing and at what ratio?

I'm using the rock oil for my 02 125 sx and it's what ktm recommended me.

Running it 40:1

Kind of new to making repairs on my bike and just gathering all the info I can before I get into the right side case and getting the clutch basket off to inspect the seal.what procedures I should be taking first before doing all that.

Because the bike runs just fine no issues there's but the excess smoke is just crazy.

A question I don't no probably commen sense but what exactly will the compression test tell me??

The bull has great compression and I really don't beleive it needs a new piston just yet.

This sounds really dumb and simple but is the plug just fouled? I had a time where I fouled a plug and it have the exact signs as a blown head gasket (white smoke, burnt smell ect). Otherwise top it off with coolant and make sure it's got enough tranny fluid then ride it for a while and check both again

True right on for the info going to go for a new plug see how it pans out,then the other options just been sooo dang busy right now

Covering the basics is always the first step.

 

clean your air filter if it has any rides on it.

 

check your spark plug too. Id test with a fresh one.

 

Do you know what your jetting specs are? If not, find out, then compare to other similar bikes. I belive that FMF's site has jetting specs based on thier pipes, but it should be close.

 

How does your altitude compare to the previous owner's riding location?

 

 

I had to buy a different needle, much leaner. It made a big difference.

 

A compression test will tell you how much compression your piston is making. This will tell you how healthy your motor is. KTM provides specs for min amount of compression.

 

 

One last thing. When your trying to get help from others, do yourself and us a favor by providing us with the most details in a logical manner as possible.

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