Rattling noise coasting with clutch in

[gog]

Took my 1100GS on a jaunt yesterday and it seems theres a metallic rattle coming from somewhere within the engine but its really only noticable coasting with the clutch in. It sounds like its coming from the front of the engine but its hard to tell when youre sat on the bike and moving. Hard to describe but it sounds a bit like when the timing chain tensioner was knackered on my airhead, the chain clattering about a bit more than it should. The noise on the oilhead is louder though. As soon as the clutch is released at all the noise goes away. Could be my imagination but sounded louder going downhill (i was up a mountain track, coming back down some steeper bits)

Worst case i guess is theres something rattling about in the gearbox, but all gears select fine (if a little clunky, but AFAIK theyre all a bit clunky). Mine is 1995 so assume early gearbox. 81k on clock but no history so no idea if its been rebuilt.

Could be unrelated, but i dropped from 5th to 4th going around a corner at about 50mph and released the clutch a bit too quickly. Felt like for a split second the engine stopped and back wheel locked with a chirp, then resumed service as normal. Think i skipped a few heartbeats.

Any ideas?

 

[Deleted account 210214001]

Hi, gordon,

Saw you post this over on ADVRider, too. Hopefully one of the fellows around here is nearby and can come take a listen for you.

Good luck!

Bohdan

 

[gog]

hi bohdan - dont think theres many of us on this forum up in Scotland but i should hopefully get some time this weekend to see if i can figure out what the noise is and sort it!

 

[Steptoe]

Don't coast with the clutch pulled in as they are noisy ridden in this way due to all the moving parts between the clutch and final drive being under no load.

 

[gog]

Thanks Neil. I know its not good practise to coast, and I do avoid doing it usually. If its normal for it to make some noise then im happy, though Ill still do some investigation to satisfy my own curiosity, as it is reasonably loud.

 

[Deleted account 210214001]

Don't coast with the clutch pulled in as they are noisy ridden in this way due to all the moving parts between the clutch and final drive being under no load.

patient: Doctor! Doctor! It hurts when I do this!
doctor: Then stop doing that!

Neil, always with the pragmatic advice.

 

[DrFarkoff]

Like Many of us Old Hands say "Start with Diagnosis first, not supposition!

first things first drop the oils into clean containers and check for sparkles or discoloration and if the oils are clean and you are still not happy Drop off the FD and check the propshaft for play at the joints

Oh and Neil is right! If it only does it when you coast with the clutch in? The Don't Do That!

Thanks Neil. I know its not good practise to coast, and I do avoid doing it usually. If its normal for it to make some noise then im happy, though Ill still do some investigation to satisfy my own curiosity, as it is reasonably loud.

 

[gog]

cheers - oils all clean. ill just 'not do that' and carry on

 

[DrFarkoff]

on a note I have found that the 75W90 fully synth is "thin" and have revereted back to heavier more viscous oils

(Ducks head and stands by for incoming )

Basically its the same with 10W40 in an oilhead EVERY time you start them up it will rattle put in 20W50 aas per original spec and it wont

I'll not get into theory but I have achieved Nirvanna in my own head as to what oil goes in my BMW's

20W50 or 15W40 in the engine
EP90 GL5 in the gearbox
EP75 W140 GL5 in the FD
and ONLY Mahle oil filter OC91D for Oilhead and Early K bikes
The other manufacturers are budget and if some cnut has mis installed or over tightened You are Fucked later on Mahle "seem" to have more metal and stand a bit more work !

 

[gog]

cheers jay. aye i have put in decent oils, 20w50 in the engine, 80w90 GL5 in both gearbox and FD, and mahle filters all round. still to do the fuel filter, will do that when i take the tank off to try and fix my dodgy fuel gauge pot.

almost put the 20w50 dino oil i use in my airhead in to the oilhead, but found out (last minute) that apparently its not up to spec.