RGS Primary

RGS-Sprint

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Hi Folks. First time posting on this site - Looking for some knowledge. I removed my primary cover today in order to free up my clutch plates. Once I'd removed the cover I saw this spring (see photo) in the oil tub. I cannot work out what it is or where it goes and am hoping that one of you knowledgeable mechanics can point me in the right direction. Thank you in advance. It's an 84 RGS by the way
spring.jpg
 
It's the spring for the chain slipper tensioner. It's function is to vaguely maintain the primary tensioner in the vicinity of the primary chain.
Paul
 
Don‘t throw it away. It is needed. 😄
The round part in the hole of the tensioner and the two legs against the inner wall of the primary cover, nsioning screw going throu the two legs.IMG_0261.jpeg
 
Don‘t throw it away. It is needed. 😄
The round part in the hole of the tensioner and the two legs against the inner wall of the primary cover, nsioning screw going throu the two legs.View attachment 90055
Also incorrect.

The legs are positioned in the tensioner hole, the rounded end bears against the primary cover, as in the diagram. That way round, the cover, or crankcase in the case of the 750, is not damaged from the sharp edges of the spring legs

The Mk II triple primary cover has a small bar on which the spring rests. When reassembling, place the tensioner pivot with the small chamfered end in the cover and slip the tensioner with spring over it. Offer the assembly to the crankcase using the larger chamfer of the pivot pin to guide it into the bore of the case.

piet
 
Also incorrect.

The legs are positioned in the tensioner hole, the rounded end bears against the primary cover, as in the diagram. That way round, the cover, or crankcase in the case of the 750, is not damaged from the sharp edges of the spring legs

The Mk II triple primary cover has a small bar on which the spring rests. When reassembling, place the tensioner pivot with the small chamfered end in the cover and slip the tensioner with spring over it. Offer the assembly to the crankcase using the larger chamfer of the pivot pin to guide it into the bore of the case.

piet
You are right, it is the other direction 🫣
 
Beware, there are/were reduced diameter after market springs around, in my learning years, had a thin one fail and let loose on the primary drive, chewed up by the primary chain, that motor still has issues to this day as a noise i cannot locate, at idle, the motor was perfect prior to this sub spec spring failure.

That was 20 years ago or more, did not bother with that spring for all motor reassemblies from that time on. So the primary is a little more noisy than the usual racket going on in there. One less item that can fail. HTH j edited sample of springs removed over the years, dont use these springs at all, even the proper factory.
 

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This may be the most mysterious piece on a Laverda...many have found them and tried to figure out which way to reinstall it.

You will need to re-tension this after reinstalling the side cover. A search will give you the method to use.
 
that motor still has issues to this day as a noise i cannot locate, at idle, the motor was perfect prior to this sub spec spring failure.
If you put the donk back together without it from that day on, Jon, maybe it's the reason for the mystery noise?? At idle I'd imagine a little clatter between tensioner and the domed end of the tensioner bolt. A theory only ...
 
Nice suggestion Mr Q, it sounds like a chaff cutter, which points to a rhythmic damaged chain section cyclic noise pattern, you would have to stand near it to believe the commotion, run the motor without the primary chain and it is still there. My inclination is a part of the spring entered the left side crank bearing. Performed the many tests to isolate the actual source, have to pull the motor down to rectify it properly, though better to diagnose the source before disassembly as otherwise, luck then plays a part spotting the root cause. Almost like bearing spinning in the cases type of sound. Been like that for 20 years, like a "friend" you would miss when rectified, well not missed too much, a smile here.

Of the motor rebuilds here, never really heard much of a difference with or without the hairpin spring. Primary tensioner i set to the 1m/m ( maybe 1.5m/m if i have to ), around one turn of the adjuster backed off once the whine is heard on a double single primary setup. j
 
Spinning mains was an issue with my motors from year dot. All my mains are now pinned. And I know what you mean by tracing noise sources - the horrible random scraping sound I was getting ever so occasionally last Sunday during a 300km ride a good example. Thinking I'd found the reason, I set about to eliminate that poss and the sound disappeared - so far so good. If it hadn't been the starter clutch I was staring down another strip-down!
 
it sounds like a chaff cutter, which points to a rhythmic damaged chain section cyclic noise pattern ...

Hey John, a trick I've found very useful to determine where a noise is coming from is to estimate the frequency of the sound in relation to engine revs. Things in engines (crankshaft, camshaft, clutch, primary chain, etc.) rotate or cycle at different speeds. The primary chain cycles at near enough 1/3 engine speed and the clutch at 1/2 engine speed. Then there's the ball or roller cages within bearings that rotate at a fraction of shaft speed, or the rollers themselves that rotate at multiples of shaft speed. Once you've figured out what fraction or multiple of engine revs the noise is, look for something that cycles at that speed.

When the big ball bearing behind the final drive sprocket (on the sleeve final drive shaft) in my Jota went tits-up, I counted the beats of the rumble as I gently nursed the bike back home. With a rough idea of what the gear ratios were, and by applying some mental arithmetic, I was 90% sure which gearbox bearing had failed by the time I got home. Sure enough, when I opened up the cases, I found a disintegrated ball cage in that bearing.

Just doing it by ear and counting beats will give you a surprisingly accurate estimate of frequency even if the clunk or rumble is happening several times a second. A musically talented dude like yourself should have no trouble counting beats ;)

But I'm guessing a man such as yourself probably has a microphone and an oscilloscope lying around the place. If you can see the cyclic noise peaks on the scope (against the background engine noise), that should give you a very accurate frequency measurement.
 
Damned clever Cam, when can i drop the bike around for you to doctor'un as the hillbillies would say, grin. Yes have all manner of diagnostic equipment here, diy jigs et al. The most notable aspect to overcome is the actual source, appears/sounds like it comes from many sources, even with a mechanics stethoscope. Even swapped primary covers. Hard to run a motor with the primary cover off, tried it, what a mess, me and workshop alike... give your suggestion some attention.

You must have been well pleased when your deduction Cam ( just call you Holmes ) was on the money...self satisfaction has no limit...j
 
Chris, its a diaphragm type stethoscope, had to, kept using the wrong end of a metal shaft through handle screwdriver... grin. Then i thought the steth was faulty as only could hear on the right side, swapped the ear pods around and still left side did not work....oh oh... playing live music in front of my then 1200watt bass stack has left its mark, not least room ambient/speech level Tinnitus all the time.... eh? Whats that sonny??
 
Chris, its a diaphragm type stethoscope, had to, kept using the wrong end of a metal shaft through handle screwdriver... grin. Then i thought the steth was faulty as only could hear on the right side, swapped the ear pods around and still left side did not work....oh oh... playing live music in front of my then 1200watt bass stack has left its mark, not least room ambient/speech level Tinnitus all the time.... eh? Whats that sonny??
I’m hearing you Jon 😉

Peavy 1000w with 18” bottom, topped off with 4 x 10” stack, before FOH, has left me with tinnitus too. Like sticking your head in a W bin, or ear up to a 45/65 all night…. It only affects me when I’m awake 😆
 
Maniac Chris, unlike myself, 2 by 15" times two JBL custom design, 2 by 12 on top Martin copy. Ditched for 2 by 15" by two, and two of 200W all valve amps on each 2 by 15", no tone stack, just 12db of defeat negative feedback loop, labelled "Afterburner" switch, used for last song and encore if lucky. 18" main your above me Chris.... and yes 4 by double W's when i worked for pro sound company, each the width of a pantech. Dem were da days, constant ringing in my ears tells me so... FOH ( front of house ) upper bottom...venerable JBL 4560's.. 8 of those... ring radiators... 12 of those... 120KW light show... better sign off on this diverted segment... blind and deaf... close as, j
 
playing live music in front of my then 1200watt bass stack has left its mark, not least room ambient/speech level Tinnitus all the time.... eh? Whats that sonny??
After my recent brain surgery, I was deaf as a post in my right ear. All I had in that ear was screeching tinnitus. It was quite unpleasant, and I was worried that the damage might be permanent, but the doc said it should sort itself out in 6 weeks. It actually took 2 months before I noticed an improvement. It's now 4 months post-surgery and my hearing has fully recovered.

I hated being deaf in one ear. It threw my perception of my surroundings off because I couldn't tell where sounds were coming from. You don't realise how important that ability is until you lose it. I now have a lot more empathy for people with hearing impairment.
 
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