Too much rich mixture?

[HardDriver]

Hi, I have a kawasaki kmx 125 1997 year. From front expansion chamber limiter is taken out (washer)

I don't know, but it have or not more limiters this bike?

Also, my bike starts without choke, my spark plug is black and until 6000 rpm bike is choking then goes like hell...

So I think the bike is running too much rich? My main jet is 107.5, the original is 102.5, so I think it's the problem, yes?

But what about exception that limiter - washer was took out? Maybe then it should be 103.5 or 104.5. I don't know really in all of that.

Also, maybe the sport air filter would help (to make more air)? Because the 107.5 means more power, but need to adjust the bike...

SO REALLY NEED HELP HERE, GOOD ADVICE .


Is this a sport air filter https://www.ebay.com/itm/Kawasaki-KMX-125-Luftfilter-Twin-Air-Sportluftfilter-/130642388904?hash=item1e6ae4a7a8&vxp=mtr ????

[RhynoCZ]

Why and who put the jet there and are you sure the choke is not stuck fully/partially closed? Also, bigger jet does not simply mean more power.

Good advice: put it back to the factory specs or pay someone to tune the engine up.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[MCN]

The OEM fit a filter that will prevent shit going into the engine. This can be anything not small enough to get through the filter.
They design the filter cloth to only let air and particles that are too small to be able to cause damage.
If stuff gets through the problem is compounded by the effects of combustion on whatever it is. Grass seeds for instance will burn and turn to carbon. The hard Carbon will wear soft pistons and cylinders. Over time it make the cylinder big and piston small.
Lots of folk fit after market filters to engines to increase airflow to burn more fuel.
If its for racing then the engine probably doesn't run for as many miles as a road vehicle so a less restrictive filter will not be a concern as the engine doesn't breath as much air over time.
Race tracks are not as dusty.
Extra wear due to a more open filter is not impossible but it should be a concern.

You could also fit a bigger filter, if there is space, which will let more air through but still hold back all the harmful shit.

What you describe is over-fueling.
You may be able to adjust the carburettor fuel settings without changing parts. But I'm not sure what you need for your bike.
It's tea time and I'm Hank Marvin.

Someone will jump in with the fix I'm sure.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[stevo as b4]

There's no other restrictors on the KMX125 except the removed exhaust washer you've taken out.

The 107.5 main jet is 2 sizes bigger than std. If the bike is running the normal oil injection and the airbox lid is intact/ not been modified, then go back to a 102.5MJ.

personally since someone was in there before I would remove the carb, and strip it down for a good clean, and then check all of the specs and settings against the manual. Everything from float height, pilot jet, needle taper and clip position, and the main jet also. Make it all standard like RhynoCZ says, and then try from there.

If the air box lid is missing, or has had the intake snorkel part cut out of the lid, then you will need to up-jet the carb, as it does seem to have an effect on airflow, and people have modified the air box lid on KMX 125's to try and improve performance, but you need the correct jetting changes to suit or it will run worse than std or too lean.

The Twin air filter seems to be a good quality part, but I would have doubts how any aftermarket foam filter is going to flow more or less air than another foam filter if fitted into the std airbox.

[RhynoCZ]

[MCN]

[Ariel Badger]

You get more air through with no filter.
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Bikers make great organ donors, get 115 on your licence today.

[MCN]

[orac]

I have one thing to add to this, actually 2:

1) have done anything with the mixture screw
2) MCN go away - if I am getting irritated with you, you must be seriously annoying.
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Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[MCN]

[orac]

I very much doubt I can learn very much you at all.

manufactures and tuning companies spend huge amounts of time and money to get these things correct.

do you know how to calculate stoichiometry for petrol engines. I reckon not. if you really want to get anal about it, you need to take into account everything that enters the engine, every different type of gas and every compound found in fuel - when you can do this you can recommend the surface area of filter that should be fitted, then you can tell every one the exact dimension of the pleats that need to be folded into it

there has also been a lack of a mention about float high too, there is another thing that can affect the running of a machine.

if I were the op, I would take the carb off, clean it thoroughly, set it back to standard (inclusive of main jet), with a standard air box then check how it runs, a bit of hot plugging and I suspect that a half turn out on the fuel mixture screw is all that it will be needed.

it would be helpful to see pictures of the plug, it may not even be a fuel richness issue, but an oil issue as it contributes to the combustion cycle of 2 strokes engines.

tuning engines is not a simple task, it takes time and money, and if you get it wrong enough it can be really bad news.
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Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[MCN]

[P.]

Orac just enemy the little failed abortion.

[MCN]

[orac]

hmm manners hey, yet you are the only one calling people names and telling them they should have been aborted. maybe you should take a look at yourself before you tell anybody what they are, what they should have been and what they should do.

insular small minded bully with a napoleon complex would be a great description you
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Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[MCN]