QuestionQUESTION: I Have a 1995 Ferris 60" 22hp model CV22S and it seems like it's working on 1 cylinder. It bogs through thick grass and sounds like its miss firing. Any idea on where to start with troubleshooting.
ANSWER: First check for a spark at each cylinder, are they both getting a strong blue spark? Are both spark plugs in good shape? After it is has been running and upon plug removal what are the plug conditions, dry, or wet? Is the fuel filter clogged, is the air filter dirty? Is the fuel cap vent hole clogged, or blocked? The list is rather endless, but this are the initial check points before proceeding with further tests...Tom
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QUESTION: Tom,
I have done the following with no results. Replaced fuel filter and verified fuel going into the carb. Replaced both plugs and checked spark gap as well as the coil gap to the magnet. The owners manual give a very good ohms test for he coil whick I did and passed The engine runs but rough still. I removed both plugs and found that 1 plug seems normal (dry and brown) and the 2nd black and wet. I checked the spark at by running the engine and grounding the plug to see the spark. Both sides are sparking. I'm stumped. what do you think?
AnswerSeems the 2nd cylinder is flooding out. You said you saw a spark at the 2nd cylinder, is it a good blue spark? Not a weak one? If it is a good spark, I'd be doing a compression check and comparing the values of the two cylinders. The cylinder needs three things to fire, 1. spark, 2. fuel, 3. compression....Seems for sure you have 2 out of three, but do keep in mind, that's a rough theory, the true theory is, A good strong spark to fire correctly, the right fuel mixture, and enough compression to ignite the fuel. You have one of three conditions, either too much fuel to be able to ignite, a spark too weak to ignite the fuel, or weak enough compression to not be able to compress the mixture into a combustible state.............I would just have to be blaming the ignition on that side, if and only if the compression test told me the two cylinders where in good shape. Hard for me to believe the fuel supply is correct for one cylinder and not both, they feed from the same carb, and intake. The cylinder either isn't firing, or firing very weak, and not burning all the fuel on that side. That's why the plug is black, and wet. One thing to check, I'm not sure on the Kohler, but most of your two cylinders, have a electrical component called a time off delay, or some call them a time delay module, these make the coil be able to hold back the spark at certain times, which results in the coil building very high voltage to then release to the spark. If this isn't working correctly, the coil will remain in a closed circuit never building enough voltage, or not enough voltage to fire the fuel mixture. If this is not working correctly your coil still will check out fine, for the fact it is fine. it's just not being allowed to build enough high voltage. I had to change one on a Kawasaki this week.......Tom
