Screeching noise from primary drive

S

stevepm2011

Hero member
Location
Cologne, Germany
G'day all,

Started the Series 2 Jota today, after a year or so of fettling various knackered bits, including the clutch, carbs, starter, exhaust, brakes, forks, wiring, stands....
I primed the oil pump, and spun it up on the starter until I could see plenty of oil coming out of the holes in the cam blocks before starting, so lube system is fine.
It starts and runs fine, no leaks etc and the motor runs on 3 cylinders, is smooth and quiet.
The clutch works, and gearbox has 5 gears and one neutral. :o
However...
I am getting a screeching noise from the primary drive side, sounds like a dry bearing.
Turned it off once I knew where the noise was coming from, and opened a beer.
Anyone here recognize the symptoms, so I know where to look when I rip the primary case off?

(Forgot to take pictures of the screeching noise, before anyone asks)  :D
Steve


 
Crank end or clutch end?
In neutral or does it go away when in gear?
 
I had the same twice, sounded almost the same. One was the bearing that sits behind the ignition-pickup-plate, one was - indeed the chain-tensioner. Replaced Chain and tensioner and noise was gone.

The series 2 Jota (if 120?) can have 2 single chains. they digg a grove into the chain-tensioner faster than the triplex-chain....
 
Grant,

Apologies, you meant the primary chain tensioner?
I somehow read cam chain tensioner...
I fitted a new Mercedes duplex chain from Andy, and a new tensioner, so need to take a careful look.
will try it...

Steve
 
Basically try anything and everything that can be tried before ripping it down.
Try putting a screwdriver to your ear with the tip resting on the casing. Move the tip around the area to try to locate the source of the noise.
Is everything under the ignition cover tight enough?
Does the engine have enough oil in it?
 
Hi Lothar,

The bike is a series 2 180, so same clutch setup as an RGS, with the outrigger bearing on a tripod casting.
That bearing seems fine, I greased it before re-assembly.
The bearing behind the ignition pickup also seems perfect.

Question:
Although the oil level is between the min. and max marks on the dipstick, I only got a few drops of oil when I removed the primary cover. Meaning no oil in the primary chain case.
Is this normal?

Steve
 
Grant,

Next steps:
Fill oil to max mark.
Back primary chain tensioner right out, so no contact to chain.
Start the bugger
If noise still present, try the stethoscope approach as you have described.

Trying to avoid having to pull the clutch drum off...

Steve
 
Series 2 has a drain hole in the lower crankcase half, whereas older ones don't.
Older ones tend to retain quite a bit of oil so when the primary cover is removed the oil spills out.
Series 2 less so.
 
I backed the chain tensioner right off, oiled everything in sight, put the primary cover back on and topped up the oil.
Noise is now gone. 8)
My guess is that it was the combination of a fairly tight new Mercedes duplex chain, plus too much tensioner (even though it was barely more than finger tight)
Could also be that the primary chain and tensioner were too dry.
Thanks to both Grant and Lothar; I owe you guys a beer. Just need to figure out a delivery mechanism....

Steve
 
Steve, I was told primary chain tensioning is:

1). Engine cold.
2). Tighten tensioner up - don't force it too hard.
3). Back off 1 1/2 turns and lock bolt in place.

Job done!
 
Simon,
Sounds reasonable.
At the moment the deflection in the primary chain (using finger pressure) is all of 3 or 4 mm, so  I reckon it doesn't really need the chain tensioner at all.
I think I will try as you suggest once it has done a few thousand km.
Thanks,
Steve
 
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