Hard-Starting FJ1200: Will A New Battery Help? | ANSWERS

Would upgrading to one of the new, smaller, lighter batteries provide any benefits?

Q: I have a 1993 Yamaha FJ1200 with about 65,000 miles. I have three questions: First, the engine has a bit of trouble restarting on warm summer days after the bike has been running. Is this normal? Second, there's some oil dripping onto the cooling fins of the left side of the cylinder head. And third, would upgrading to one of the new, smaller, lighter batteries provide any benefits?

Ken Worthy
Victoria, BC

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A: Hard starting when the engine is warm could be caused by several problems, but the first thing to check is the bike's electrical system. The resistance in an ignition coil increases as the unit's temperature rises, and the 21-year-old coils in your FJ might not be up to the task of lighting the fire in a hot engine. If that's the case, upgrading to a new battery type probably won't do much except reduce weight. Rather than throwing new parts at the problem, take a methodical approach. Have the battery load tested. If it's even a quarter of the age of your bike, it may be faulty. If it checks out, have the coils checked next. If all the electrical components are up to spec, turn your attention to the carburetors. The FJ1200 isn't particularly sensitive to carb synchronization, but if one or two are far enough out of sync, you could get hard starting. A leaky airbox will have the same effect, as will air leaks anywhere upstream of the engine. Check the boots between the airbox and the carbs, and inspect the carb manifolds for cracks.

Oil leaks can be hard to diagnose, but this one should be relatively simple. If the oil appears to originate below the eighth fin—where the head and cylinder block separate—it could be a head gasket. However, the FJ is considered to be a pretty robust engine that suffers relatively few head-gasket leaks. More likely, the oil is coming from the cam-cover gasket. To find out, thoroughly clean the engine, start it, and let it run until hot. Use a powerful flashlight and look for wet spots. You can use a commercial leak detector or simply dust a little talcum powder in the area of the suspected leak. The powder will discolor quickly in the presence of fresh oil.