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diagnosing lean vs. rich in a 2 stroke

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I am new to 2 strokes.  I picked up a 2005 KTM 300 EXC.  The bike was in a pretty sorry state when I got it.  Stripped float bowl screws are never a good place to start. Anyhow, being new to 2 strokes I don't have any background in diagnosing carb setup. People refer to a bike sounding blubbery but I have no idea what that sounds like. Are there any simple, basic diagnosis tools like hanging idle sort of stuff I can use to determine if I am lean or rich? 

Thanks 

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You'll tell when it's perfect.  It'll idle tits and it'll rev perfect into the powerband without hiccups and sound just right. You'll hear if it's lean or rich. 

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12 minutes ago, Adam N. said:

I pretty much never ride on the main.  

Yes, but that doesn't matter. You still have to tune for it as if you did, as the main and needle are intertwined.

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Rich kills throttle response, power, causes burbles and four stroking, excessive smoke and spooge out of the pipe.  Lean causes detonation and makes the motor bog under quick throttle openings.

The plug color mostly shows how well the main is working.  You can tune every other circuit by feel.  Lean it out just until it is crisp and stop right there.  Too crisp indicates a lean condition which can burn a motor down if you're just trail riding down dirt roads.  I like to run the air screw just slightly rich to afford a margin of protection, just not so rich that you lose that closed throttle to 1/8 open crispness.

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Lots of jetting info on those bikes, what is your current jetting?

JD jet kits work very well on them and come with great baseline setttings which may be your best option since you are new to the 2t world. 

Spooge and smoke will indicate rich.
 

Bog off the bottom, hanging idle, and surging are lean signs. 

Knowing your current jetting will the most important and first thing to do. .

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12 hours ago, Adam N. said:

I am new to 2 strokes.  I picked up a 2005 KTM 300 EXC.  The bike was in a pretty sorry state when I got it.  Stripped float bowl screws are never a good place to start. Anyhow, being new to 2 strokes I don't have any background in diagnosing carb setup. People refer to a bike sounding blubbery but I have no idea what that sounds like. Are there any simple, basic diagnosis tools like hanging idle sort of stuff I can use to determine if I am lean or rich? 

Thanks 

google spanky's jetting guide it explains a lot

ditch the ktm needles and get a suzuki needle ( there is lots of info on these forums about it )

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7 hours ago, kxrob said:

 

ditch the ktm needles and get a suzuki needle ( there is lots of info on these forums about it )

The reason I posted this is that I am moving from the stock KTM needle to the Suzuki needle.   So, in essence I am jetting from zero.  I am staring with a new to me main, needle, and pilot.  Sure, I am using someone else's recommendation but there are so many and so varied opinions. 

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For pilot jet and needle settings on my YZ125,

I've become accustomed to adjust on what 'feels' the best at lower rpms and acceleration

rather that what the engine sounds like as when it runs it's best, it sounds a bit 'too lean'.

 

I'm more conservative on the main jet though !

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