View Full Version : engine clanking sound
02-28-2007, 11:41 PM
My 94/750 has been making a loud clanking noise at idle rpm for a couple of years. It's loud and sounds like a hammer being hit on a metal surface. the sound appears to be coming from the crankshaft/crankcase area. The noise goes away at above 2k rpm. In my efforts to get rid of this very annoying hicup:shock: I checked and ruled out any problems with the clutch basket, timing belt, crankshaft bearings, piston rod bearings, or the cylinder head which I had ported and grinded down last summer.
Does anyone have any ideas what could be causing this very annoying problem??? Could it be a bad oil pump? I also noticed I could move the starter clutch gear in and out a good half inch and am not sure if that is normal. Any suggestions or expert advice greatly appreciated.
03-01-2007, 12:14 AM
My 94/750 has been making a loud clanking noise at idle rpm for a couple of years. It's loud and sounds like a hammer being hit on a metal surface.
that can't be good....
03-01-2007, 10:42 AM
I know!! Funny though it's been doing it for years with no real change. I've torn the motor apart and can't find anything wrong with it too. I would think such a loud engine noise would be easier to diagnose.
03-01-2007, 12:05 PM
What about a bad exhaust leak? Also, one time I had a plug wire shorting to something, made a loud CRACK sound every time it arced but still ran relatively fine. I found it while looking under the tank at night, pretty cool light show.
I know it's kinda hard to tell, but what's the frequency of this noise? Every time the engine turns over, half that, or what.
03-01-2007, 05:28 PM
Check the valves, one may have loosened. I noticed my bike was much quieter after I adjusted the valves.
03-01-2007, 06:31 PM
the noise happens every time the engine turns over, or every time the crankshaft makes a revolution I think. At idle speed about 3-4 clanks per second.
12-09-2007, 05:30 PM
Anyone still reading this post, the problem turned out to be the alternator. The internal bearings were worn, causing the shaft the wobble at low rpm's causing the alternator gear to clank on the transfer gear. I couldn't isolate the sound until I synced the carbs, which allowed the engine to run a lot smoother, which made the sound a lot quieter and easier to isolate.
12-09-2007, 05:51 PM
Good job on the fix, and for posting the results.
--Might need to change your screen name now though :)
12-09-2007, 06:00 PM
12-09-2007, 07:20 PM
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