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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: lhead on October 08, 2013, 08:45:04 AM
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Having nothing better to occupy my mind I suppose, I've wondered about the whine that K bikes make. The common opinion here is that it originates in the fuel pump.
In order for that to be true, the pump would have to be variable speed, because at the whine varies in frequency with the RPM.
I also know that the fuel pump motor is a fixed speed motor with constant ouput and the FPR controls how much fuel is diverted back to the tank based on fuel needed for engine speed and load.
Thoughts?
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the whine comes from the fuel pressure regulator...
j o
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which whine? The pump whines as does the gear drive, the regulator Id consider more of a squeal.
The engine is not directly connected to the clutch like a car. The crank turns a gear that turns the gear for the output shaft that in turn turns the alternator drive. The gears have some whine to them.
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Whine? What whine?
I do not hear this whine you speak of. :dunno2:
Maybe the Remus header & pipe take care of it? :clap:
When the bike was new to me in 08 the fuel pump did make more niose when the gas was low. Regular treatments of Techron have
eliminated this any with exception of start up. Turn on the ignitition and I hear the pump energize, then I don't ever hear it again.
Transmision .. What gear oil are you running? And, have you aded any additives?
Ditto for the final drive.
Other than those & the tires, no idea what you are hearing.
Cqn you record & post it?
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I didn't say it was abnormal. Every K bike I've heard has the noise. It's probably FPR or gear related. BTW I'm running Lucas syn 80w90 oil in both trans and FD. Just changed over the weekend.
Tires would have no bearing on it - i hear it whenever it's running. Even in the driveway.
Suzuki GS bikes in the '70s had the same kind of noise. Straigh cut primary gears were the source of the noise.
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The K75's have straight cut gears for the primary drive. K100 and k1100's have helical gears. This would be part of the reason K75's are louder, whine wise.
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If you haven't heard the whine you haven't twisted the throttle past the halfway mark. :riding:
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I kinda like that my K75 sounds like it has a supercharger, to be honest.
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Better helmet and or ear plugs.
Ride hard, ride fast, don't worry about the whine.
Using the Lucas syn 80-90 is good.
I think the Red Line Shock proof gear oil for the transmission is even better.
Or add Guard dog moly to the Lucas.
These would have no effect of course on teh bike just sitting & reving.
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Better helmet and or ear plugs.
Ride hard, ride fast, don't worry about the whine.
Using the Lucas syn 80-90 is good.
I think the Red Line Shock proof gear oil for the transmission is even better.
Or add Guard dog moly to the Lucas.
These would have no effect of course on teh bike just sitting & reving.
I didn't say the the whine was an issue or problem. I was just speculating as the origin of the sound. My helmet and earplugs are just fine, thanks.
But...I appreciate your concern.
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I remember the whine diminished back when I had a tank cover. Nowadays with a pipe, old man hearing and waaaay too much familiarity with the bike I don't even notice it.
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" I didn't say the the whine was an issue or problem. I was just speculating as the origin of the sound. My helmet and earplugs are just fine, thanks.
But...I appreciate your concern. "
No problem, point taken, ride safe brother.
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K75 has a counter shaft that really sings. Love the sound. Last bike was a GL500 Sounded like a 10,000 rpm shaft drive with none of the cache of the brick. If you don't like whining get another bike or a new wife or older kids!