RGS static timing problem.

R

RGS-Ned

New member
Hello everyone, I hope somebody out there can help me. I bought a crashed RGS 17 years ago, which I've been putting back together as and when time and money allow. I would really like to finally get her on the road this year, as I'm not getting any younger. I've had the carbs ultrasonically cleaned, new plugs, air filter and battery. She started and ran beautifully for about 10 minutes a couple of months ago. but needs setting up properly. Here's my problem.
Trying to find TDC using a piece of welding rod, and turning the engine forwards and backwards using a ring spanner on the ignition rotor, the "cut mark" on the rotor indicates that TDC is 2 or 3 millimetres to the left of the P/M mark. I cannot move the ignition trigger plate any further anti clockwise to make the marks line up. I'm wondering whether the cam chain has "jumped" a tooth? The bike has 36,000 kms on the clock.
Any suggestions please.
 
Even if the cam chain had jumped a tooth, would have no effect on ig timing as that is all crank mounted.  The mark on the trigger plate is quite useless.

Ascertain 32? BTDC, make a mark on the crankcase/primary case, NOT on the trigger plate as the factory did, and strobe/adjust so the marks line up at around 2500-3000rpm.  Check ALL 3 cylinders for consistency, this is vital for the well-being of your engine.

The only influence you have on idle timing and the advance jump is the pick-up gaps.  Getting them equal is a chore, but well worth doing.  While strobing, you will find the idle timing suddenly jumps to full advance somewhere around 1800-2200rpm, this is the cause for crap running while tootling through villages at low revs.

Apart from that, junk the entire crude stock ignition system and fit something sophisticated like a DMC II from Moto Witt.  This will transform the bike like nothing else can.

piet
 
Thankyou Piet, It's a little shocking that the factory marks can't be relied apon. Looks like I'll have to invest in a strobe for now, and the Witt ignition asap.
This site is a mine of info for anyone like me who's been away from bikes whilst doing the responsible parent thing. THANKS again
 
Reggie3cl said:
Trying to find TDC using a piece of welding rod,
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Make a proper positive stop and get yerself a degree disc.
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That's stage two, stage one is welding rod/screwdriver.

                                                            Dave
 
Hi Ned

17 years waitng to get the RGS back on the road..... Wow! Major points for persistence!

the stock 120 ignition has three ignition pickups, each of which has to be "timed" or gapped correctly.

you cannot rely on the stock factory timing markings, you need to make your own as Piet described, using a degree wheel mounted on the crank end, and a proper Top Dead Centre stop, which you can make from an old sparkplug very easily.

your very best case is to spend the money on a modern ignition, which will use a single ignition pickup, save you all the timing issues between cylinders, but you can also make the stock ignition work fairly well as long as you make your own proper timing marks derived from a degree wheel.

Paul LeClair
 
Hello Paul, 17 years is a long time I know. I found her leaning against the side of a house in Colchester having been crashed weeks earlier. I had a Montjuic at the time. I got chatting to the owner who only had third party insurance, and couldn't afford to fix her himself. So I sold my Monty to buy her. Then my wife anounced she was pregnant,(bloody typical!) so she got pushed to the back of the garage (The bike, not the wife) to await my attentions asap.
Back to the ignition probs, I thought the cam chain may have jumped a tooth as TDC seems to be well beyond the P/M mark about 3 millimetres, so if the L/H piston was reaching TDC later, the rotor would have travelled that bit further. I cannot afford the Witt ignition at the moment, but will try to follow all the good advice I'm getting from everyone. Thankyou.
 
Ned,

Think you've got a wrong mental image of what's going on inside the engine.  Both the ignition rotor and the pistons are connected to the crank.  The cams/chain/cam timing do not come into the equation at this point.

It is not unusual for the factory TDC mark to be a little way off.  Follow Piet's excellent instructions and you'll be sweet.

Cheers
Steve B
 
Yes, Sorry you're right, Duh!! I don't have an engineering background (can you tell?). Think I'm trying to over complicate things.
 
:D Big THANKYOU to everyone for the help getting my RGS going. The welding rod and protractor has proved successfull. I cannot believe how much filing was required to get TDC and  32 degrees to line up. with the static timing done and 0.30 gaps on the triggers she's running again, sounds lovely. Thankyou.
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I,ve made a couple of cosmetic changes, the hooters are now up inside the fairing, an she's also got Triumph Spped Triple indicators, as the originals were trashed in the the crash and look horrible anyway. that's my daughter Emma on board.
 
Thankyou, can you believe I had this 17 years and never ridden it. Looking forward to it now though. could be the start of my mid life crisis!
 
RGS-Ned said:
Thankyou, can you believe I had this 17 years and never ridden it. Looking forward to it now though. could be the start of my mid life crisis!
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Not the start, mate, it's the end of ANY crisis! :D

piet
 
At last the cause of my timing problem has been discovered. As I mentioned before the bike had been crashed when I bought it, the accident destroying the ignition triggers and rotor. Turns out the new rotor is wrong. with the woodruff key slot being at the 3 o'clock mark. putting the full advance to around 50 degrees. Speaking to Ralph at motalia he says the woodruff slot should be at the 2 o'clock mark, which will pull the advance back into spec. She should be back on the road next tuesday/Wednesday :D
 
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