Hi guys, I have a Wacker BS60-2I, 2-stroke oil injected rammer I have a problem with. The rammer runs fine for 5-10 minutes and then all of the sudden will start crow hopping, sometimes 12" into the air. It will hop around for about 15 seconds and then run just fine for a few more minutes and then repeat the obnoxious behavior. I figured fuel was the problem so I put a carb rebuild kit in and when that didn't work, I replaced the carb. Replacement didn't help or change the situation. I was told by a mechanic that low compression was likely the culprit but I disagree given the compression is 130psi. Any thoughts, ideas or suggested repairs would be greatly appreciated. Thank you all, Bob
I repaired a lot of those at one point in my career. The crow hopping means the RPM is too low. Typical behavior of a worn out 2-stroke engine is running fine till it heats up, and then falling on it's face as clearances expand. Have you every checked the compression when the engine is hot and acting up?
I checked it cold but will warm it up and check it. If compression fails, do you suspect I can get away with piston and rings or would you suspect the jug as well?
You need to get a look in there and see what piston and cylinder look like. New rings will seal a worn jug for a while, as long as the cylinder isn't scored. It's those scratches/scoring that will cause you problems. You can see a lot of the cylinder by taking off the exhaust and shining a light in there. Are you using a high quality 2-stroke oil? Gas is new? Fuel lines and filter are new? The other item that can cause you trouble is crankshaft seals. The exhaust could be plugged too, but that usually limits RPM hot or cold. Something else to think about.......the clutch. It has a centrifugal clutch on the end of the crank. The clutch can wear and start to slip or get oiled up by leaking seals on either the engine or the rammer. 6mm allen head cap screws - about 4 of them to split the engine from the rammer and have a look. Might be a good next move if your hot compression is looking ok.