Question I picked up this bike from a freind recently and it has been sitting in a barn for a few years. It runs rough, doesn't idle well, runs hot, sputters alot during excellaration. As far as I can tell all signs lead to a bad part in the ignition system. I tested both coils and found each at 4ohms. My book says 2 ohms is good. What does 4 ohms mean? Any other possibilities?
AnswerChris, I don't see anywhere in your note about checking and cleaning the fuel system. Probably the idle jets are blocked and main jetting are partially restricted. The fuel filter could be plugged up, and the air filter restricting air flow.
You can't leave a bike with fuel in the carbs and tank for a few years and then expect it to just come to life with a fresh battery.
Ohms is a value of electrical resistance. A low or zero ohms reading would indicate a shorted out circuit, while one with above value readings indicates an open or partially open circuit or one with excessive resistance for some reason.
If both coils are the same, read off the wires and not through the plug caps, then they are probably fine. Check plug cap resistance values and see if they are all close to being the same. New caps are generally around 5k ohms. The ignition is triggered by a flywheel pulse generator coil. That feeds a timing signal to the ignition module, which computes rpm and then sends a timing signal to the coils, advancing the timing as rpms rise.
Make sure you have a fully charged battery in the bike and that the charging system is fully functioning.
I would stop searching for electrical issues until you can confirm that the fuel system is clean and flowing correctly. Some Honda models have vacuum operated petcocks which have diaphragm failures, inducing a vacuum leak and a fuel flow restriction at the same time. There is also a fuel screen inside the tank, as part of the petcock (fuel valve).
Go to BikeBandit.com and look up illustrations for your bike online through their OEM parts search option.
Bill Silver
