Im running a cr 80 shifter and for the past couple of days i havent been able to get it to fire. I checked my spark and it seems okay (in-line spark tester glows ) so i pulled the carb (pump around system) and checked all jet passages etc. and blew out carb with compressor. still no fire! WTF?? so I pull the intake boot and reed cage to check reeds and boot for cracks. all good. I looked into intake to check piston and rod assembly and all looked okay, one thing i did notice was that when i rotated the piston( via the back tire while in gear ) was that the lower crankcase is full of fuel and sloshing everytime the rod goes thru its travel. Is this normal or does it mean im flooded? if its not normal what could be causing it? any help and info would be greatly appreciated.
Definitely not normal and can see why it won’t crank. With the fuel being below the carb I can’t see how it’s finding it’s way in the crankcase, as opposed to a motorcycle where a bad float valve can cause some leakage in the engine.
I think its filled the crankcase from trying to start the engine and fuel pump has filled the crankcase from not igniting the fuel.
Gotcha. I’ve tinkered with 2 smokes for a lot of years, never had one partially fill up the crank case. It should still blow some excess fuel through to the exhaust even though it’s not lighting off, try removing the plug disconnect fuel line or cut off fuel and motor it over and maybe blow fuel out that way.
okay, i will try that and get back.
The culprit is likely to be the Pump-Around carb. When they modify the carburetor for the pump-around system, they remove the valve needle that prevents fuel from entering the actual engine.
This means you have to be extra careful when moving the kart around, especially when tilting the kart, because there is nothing in the carburetor to prevent fuel from entering the crankcase.
It’s one of the biggest annoyances of having a pump-around system, I had a Honda CR125, and that was such a pain, I converted it to a regular Keihin carburetor, potential bogging or not.
I had the same problem with my Rotax 125 Evo Max, and I couldn’t figure it out. It had fuel, air, spark, and compression. So I checked the bottom end, and it was flooded. I blew it out with a compressor; it ran for a second and died. I checked the spark plug; it had spark, but not from the electrode—it looked like it was sparking inside. Basically, change your plug and blow out the bottom end and see if that works.