Running rich - any input would be appreciated

[RastlinV]

Hello all,

Looking for a little help. New to the forums. Picked up a ZX 50 two years ago and has ran well up till now. I know that it is running rich. You can smell the gas starting. Hard to start. After it does start, it sputters till it warms up. Going to clean the air filter first. Pulled the spark plug and it is fouled. Completely covered with oil can carbon. I've never dealt with a carburetor before so any help tuning would be appreciated. Is there anything else I need to look at and adjust?

Thanks for any help.

Update
Ok, cleaned out the air filter and it was dripping with oil. The oil was blue in color just like the 2 cycle synthetic I use. It also smelled of gas. How could oil and gas be coming back out into the air filter?

[sidthesloth]

G'day RastlinV, every time the reed valves close, think of it as a slam, it sends a shock wave back through the carb causing a small spray going back, over time the filter gets clogged. When I first got my zx it was dropping oil, after some checks, I found it was from the filter.
After cleaning your filter, did it run any better? It might pay to have a look at your exhaust to see if you have any carbon build up.

[RastlinV]

Is this normal? Or something I should look at as possibly broke?

Update:

Just took the reed valve apart. Everything appears fine. No damage everything shiny.

[Shaka]

It is normal for the air filter to get covered in oil/gas.  As Sid said, every time the reeds close it sends a back pulse on the intake which pushes some of the fuel/oil back through the carb.  Does it run better after cleaning the air filter?  I would also replace the spark plug and de-carbonize the exhaust if that doesn't help.  You shouldn't really have to adjust the carb if you've never changed it and it's always ran well.  It probably is running rich due to the entire system being dirty.  The only adjustments you have on the carb are the idle mixture and the idle itself.

[RastlinV]

Thanks for getting back to me. Much appreciated.

I currently have everything torn apart and cleaning it. There was a lot of dirt/oil/grease build up every where. I hope to have it all put back together Sunday, weather permitting. I did see a lot of carbon buildup on the exhaust. I cleaned out the carbon on the cylinder exhaust and going to to order a new exhaust. The one I have is pretty rusted and I'm sure has a lot of build up on the inside. Calling around it will take a while it get here. Any recommendations on where to get parts other than the local Kymco dealer?

I also want to look to see what all other parts should be replaced. I do have a new spark plug for it. So for now I am going to clean it up and put it back together.

Again my appreciation for the feed back.

[sidthesloth]

You might also want to have a look at your variator and rollers, if worn, replacement will make it ride like a new scooter.