Grinding sound when press starter - RGS

Chappo

Chappo

Senior member
Location
Lake Macquarie NSW
Hi everyone.

I?ve got a problem I hope I can get some help with. 

When I press the starter button on my RGS, a grinding sound comes from the within the motor somewhere. The motor didn?t appear to be turning over, just this grinding, meshing sound. I had ridden a few blocks from home when it conked out, at a stop sign. I thought it conked out because it was still a bit cold. I pushed the starter button, and all I got was a grinding sound.

I moved to the side of the road, pushed the starter again. More grinding. Turned it off, and coasted most of the way home, in neutral. I only had to push it a short way. 

What complicates things is, I was on a test ride after replacing the primary chains and clutch rubbers. When I heard the grinding sound, I thought something was amiss with what I had just done. That?s why I said the motor didn?t ?appear? to be turning over. I?m trying to remember exactly what went on, after the ride, while at the time, I was thinking about how I had somehow mangled the primary chains, or pick ups, and what an idiot I was.

Where I?m up to now is:

I?ve removed the primary cover and found nothing untoward in there. All the bolts are still tight, and the chains look good. I took a photo.

I removed the starter motor, connected it to the bike?s battery, and it spun around quite happily. Seems OK. I had the brushes replaced by an auto elect, some years ago now though.

I?ve spun the gear the starter motor turns, and it only turns one way. In the direction it does spin, it spins freely, and with a noise.  A rattling, clanking type noise, maybe similar to the grinding sound, but I can?t be 100% sure.

I then took the bolts out of the alternator cover, but the cover wasn?t coming off easy, so I put the bolts back in, and thought I?d look in the manual.

?To reach the gears and freewheel, the whole alternator cover needs to be removed.? The book says.
I need to look at this freewheel? Is this the sprag clutch I?ve heard talk of?

Does the alternator cover just pull off?

Book says I have to remove the flywheel to get to the freewheel. Do I need the special locking tool mentioned?

What?s to look out for when doing this job? Am I on the right track?

Thanks heaps for any help and advice.
Regards, Darren, aka, Chappo :).

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You need to remove the starter clutch for overhaul, the alternator cover comes off with a good tug, it has a couple of dowels, the magnetism of the rotor and whatever gasket snot the last guy used holding it on. Remove the bolt in the centre of the rotor, should be l/h thread but it may be r/h.... if there is writing on the bolt head they are r/h if not they are l/h. You then need an M16 x 1.5 bolt to pop the rotor off its taper, use the front wheel spindle if you do not have a suitable bolt. Remove the small tab from 12 o clock on the big gear and withdraw the sprag clutch assembly, pull it off using the big gear to stop all the springs and rollers poping out all over the floor. Split the two halves on the bench clean and inspect. With a bit of luck a new set of rollers and springs will fix it.


    Keith
 
I had this recently on my 79 Jota, and e mailed a video to Keith so he could diagnose the noise! Sounded bloody awful.Twas indeed the sprag clutch rollers and springs. They were jammed in and the holders were split, and there were no less than 3 different spring lengths! Anyhow, with some penetrating oil and patience, all came out and a new set was fitted. Slightly more tricky was resetting the Sachse  ignition, as needed to find TDC .Actual setting of the system was quite easy so holds no horrors now...it needs a diff end rotor puller which handily comes with it.I see a few roller and spring kits on e bay but none seem to have the spring holders too, which I def needed.Slaters had it all, so I could replace the set Clem gave me which, handily as ever, he kept in stock!
 
While you havethe whole mess apart take a minute and double check that the three countersunk screws holding the backing plate onto the starter clutch are tight. I've had a few bikes in the shop with this malady and the ones on my RGS had backed out far enough that they were rubbing on the gear wheel. A small dab of Loctite on the screws will help ensure the screws stay where they should.

Tom
 
to Keith's excellent, concise and crystal clear explanation, I would add that to put the repaired sprag clutch assembly back on the gear hub, you have to offer the sprag and its rollers up the hub, press, and rotate to cause the rollers to retract a bit against the springs, so the retracted rollers will then slide on to the hub.

in addition to the springs behind the rollers wearing out and breaking and sticking, the working surface of the hub itself can get kind of worn and ripply, my own solution, within limits and without proper tools, is to spin the hub/gear on a drill or other means of rotation, and lightly hit the hub's working surface with medium fine sandpaper as it spins. There is likely some reason why I shouldn't be doing that relating to surface hardening or something, but it has worked for me in the past.......

Paul LeClair
 
Thanks heaps Keith. Great instructions those. It's given me plenty to  be going on with.
I'll post back, once I have gotten hold of this freewheel thingo.

Nick, Tom, and Paul. That's all good help and advice. Thanks.

I'll be back...

 
The 3 coutersunk screws may in fact have come out and caused your sprag clutch to jam you will see for sure if they have loosened as the heads will be burnt and damaged it is important to ensure they are loctited in.
 
I've got the alternator cover off. The bolt has writing on it, so this is anti-clockwise to remove?

I have an air impact spanner. This is the tool for the job?

Thanks all.

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I?ve have the dooverlacker off the taper. I needed the air impact spanner to get it off. Otherwise I would have had to lock the motor somehow. I tried it with a soft bit of wood locking the primary chain gears, but once I put a long bar on the bolt, the teeth dug into the wood and rolled the piece of wood out.

So, I reckon you need an air impact spanner or a crank locking tool. You also need a T15 Torx screwdriver to get the back plate off the clutch. I think I will keep taking photos and maybe do up a ?how to?. I found lots of good info when I searched, I can include that in the ?how to?.

Anyway, do I just need new springs? Some seem to spring OK, some others are shorter and look like the missing part has broken up. One spring is missing all together, but this could be on the floor somewhere.

A place I bought bolts from lists springs. This is how they list springs on their website.
3.962 x 14.3 x 0.58 Compression Spring Pkt/3

I?m assuming the first figure is the OD, the next is the length, and the third is the thickness of the material. I?ve looked, and I can?t find any instructions on their website as to how to interpret the numbers.

Where have others bought springs and/or kits from? Does anyone know the spring size? I?ve searched for ?sprag spring? and ?compression spring? on eBay, but didn?t see what I wanted.

How does it look in the photos? Have I pulled enough of it apart? Put in new springs and away I go?
Thanks.


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New springs should fix it, make sure you pull all of the old broken bits of spring out of the plungers first, might want some new rollers too. Got everything in stock here.



  Keith.
 
Have I pulled enough of it apart? Put in new springs and away I go?
Thanks.
 
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As Maurice has alluded to - check that the c/sunk screws holding clutch body to alternator rotor aren't loose - the clutch could still appear tight as it's located by 3 dowels as well. There is a  factory C - spanner to lock alternator too - regards - Phil
 

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Chappo said:
I tried it with a soft bit of wood locking the primary chain gears, but once I put a long bar on the bolt, the teeth dug into the wood and rolled the piece of wood out.
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Jamming things in the primary drive is not a nice thing to be doing to your engine. It puts a hell of a load on things, and the shafts are unsupported at the outer ends when the primary cover is off. There are people on here who can tell stories of bent shafts, stretched primary chain, and busted sprocket teeth. It may even be possible to twist the crank out of phase if you're heaving with a long bar on the alternator end of the crank. Rattle gun is a lot kinder to the engine.
 
Hi, 'Wise people wot know',

Should overhauling the sprag be thought of a preventive maintenance thing?  Or does it fit more in the, 'Don't fix it if it ain't broke' category?

See, mine works fine - well, up to now ...  :D

TIA

Craig
 
Craig -  no,  you can safely leave a triple sprag until you hear an unusual squeak /graunch sound.  Ask me how I know :-)  70,000 km mostly on standard ignition and a known lazy starter (slow to fire). When the time comes, OCT have all the parts...
 
the one in the Seth African let go at 32k, if its a new bike or you unsure then id be pulling it out to make sure the countersunk screws are loctited in, makes a nasty mess and could be quite lethal at the wrong speed, I got off lucky when it locked up at about 30kmh

the pissy little springs also seem to break down over a while
 
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