Author Topic: 81 cb650c pulsar generator?  (Read 1109 times)

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racing33

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81 cb650c pulsar generator?
« on: July 22, 2006, 09:08:25 AM »
I was checking the timing the other day and when I was checking the gap between the pulsar generator and the rotor I noticed the generator part was not sitting level to the rotor. It seemed like it was tilted just a little bit which makes it closer to the rotor on one end. I would assume since the manual calls out for a specific air gap between then that the pulsar generator should be level to the rotor. I can see where the PO has been in there as there are marks on the screw heads that hold the pulsar to the plate. Do the pulsars need to be level to the rotor?
Also when I first start the bike it sounds kinda bad. When it is warmed up it sounds excellent. When it is cold it sounds like something is rattling inside, but only if the rpms drop down below 1000 or so. Above that I do not hear it either. It sounds like it is coming more from the clutch end of the motor. Does anyone have any ideas what this could be? I have cleaned the carbs real good, adjusted valves, cleaned the gas tank, installed an in line fuel filter, adjusted the cam chain tension, and static timed the ignition timing. The bike runs real nice, idles smooth after it is warmed up, and has good throttle response. I am the third owner of this bike. The appearance of the bike would say that the previous owners had taken decent care of the bike. It still has all the decals,factory wire wraps, and reflectors. I am telling you all this so you can have a decent idea of the overall condition of the bike. I have put about 1000 miles on this bike and the sounds have not gotten any better or worse. I really do not think it is a rod bearing going bad as I have drained the oil through a clean white cloth three times and did not see any evil shiny bits of aluminum. The oil and air filters are new also. Any help with this would be most appreciated.
Bruce

Offline crazypj

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Re: 81 cb650c pulsar generator?
« Reply #1 on: July 22, 2006, 09:32:44 AM »
Sounds like carb synch, clutch rattles due to load reversals. dont let engine go below 1,000 rpm. It will have better oil pressure at slightly higher rpm (although too high rpm when cold will blow pressure switch top off, its directly mounted to pump)
The pulse generator is real common, not a fault, just someone didnt use a thin wall socket at some time in the bikes history, if you look real close you will probably see the mark where a wrench either slipped or pushed on it. dont try and straighten it out, too much chance of breaking something
PJ
I fake being smart pretty good
'you can take my word for it or argue until you find out I'm right'