Motorcycle Repair/honda cb900

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Question
Hello you have given me great advice in the past and I gt my cycle running great but had an accident that damaged my pulser pickup coil. I lost all my oil. I replaced the pickup and had bout half of a quart of oil in it I rode bike into town to gt more oil cause its my only transportation the bike stalled had to let cool then it fired again. My ? Is could that have caused my coil to breakdown or would that matter? I see most bikes have no oil in the pulse but mine is oil cooled as u know.

Answer
Brent, if you only had a 1/2 quart of oil in it, you probably seized the engine. Oil capacity is almost 5 quarts. When oil isn't getting picked up by the oil pump screen in the oil pan, you are just getting lubrication from splash inside, until it all drains down and things start to seize up due to lack of lubrication. Most likely the camshafts seized up initially with pistons being second on the list. Crankshaft bearings are all plain type, so need 60psi or so to keep the rod bearings off the crankshaft journals.

Oil cooling the pulse generator coils isn't really an issue in this case. They don't get hot really, as there isn't a lot of heat generated by their function to trigger the spark units. They are located down there more for convenience of design than anything else.

Running your blood volume down to 10 percent of normal would kill you dead... I would be surprised if the bike doesn't come up with more "sudden stops" like that now, even with a full load of oil back inside the motor. Once parts have seized up, the damage is done and the roughed up surfaces start shedding metal into the oil system where it gets picked up and hopefully strained through the oil filter, but tiny particles will get through and continue to contaminate the oil supply over time. Even with out further seizures, I would monitor the oil supply carefully looking for fine particles of aluminum to go into suspension in the oil.

Hondas are pretty rugged by design, but running them out of oil will kill the best of engines, either right away or it will usually shorten their lives quite a bit. I would be riding with my left hand covering the clutch lever at all times, in case something sudden happens internally....

Bill Silver

Motorcycle Repair

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Bill Silver

Expertise

Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.

Experience

I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

Organizations
VJMC (Vintage Japanese Motorcycle Club) of North America

Publications
VJMC newsletter, as editor for two years and as contributing editor currently.

Education/Credentials
3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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