twin oil circulation

[Samuel]

Enjoy your evening meal

[clive]

Finally its all back together, started about third kick. Oil supply to rockers confirmed by oil spraying everywhere! now to get some miles in at running in speeds many thanks for the advice from the website and the West London crew.

[clive]

However the problems continue.

Twin driving me crazy with miss fire at speed, tickover perfect. I have tried checking the pushrod clearance, checking and resetting the timing, new plugs, cleaning the mag pickups and checking they are free in holder. Cleaned the HT cables at mag end and cut and refitted at plug cap end.
Symptoms appear to include sooting (not oiling) up of the plugs. Is this the cause or a symptom due to misfire? I was having problems with sooting up before the rebuild but thought I had found the cause during the dismantaling when I found needle was on the top rather than 3rd slot.
My suspicion is now focused on the points which at some stage had lost the little retaining clip and may have become worn/damaged, although the clip is now replaced or maybe the condensor? Any other ideas?

[g80csp11]

What Carb settings are you running ?
By changing the needle from top to 3rd notch have you not just made the bike run richer (sooting)
it might be the reason for why the previous owner had it running there

376/78 for a 600CS
Carburettor Specification: 376/78
Make: Matchless
Model: G11CS Twin
Engine Size: 600cc O.H.V.
Carb Type: 376 Monobloc
Year: 1958 onwards
Number of Carbs: 1
Needle Position: 3
Internal Bore: 1 1/16in
Throttle Slide No. 3.5 Cutaway
Main Jet Main Jet - Size 280
Needle Jet Needle Jet - Size 106
Pilot Jet Pilot Jet - 30cc

[clive]

Peter, Carb was a red herring. Firstly I misinformed you what I should have said was the needle was in the bottom slot, and somehow done by me not PO, so guilty as charged, explains my need to keep reducing the main jet size when trying to jet it for an air filter before the rebuild. After readjusting the pilot screw sooting up seemed to have stopped but misfire remained. New points did not resolve. Borrowed K2F from fellow West London member, exchanged points plate, no improvement so decided to install whole mag. Whilst doing this I thought I would reuse my pickups and HT cables, plug caps and then change them if the different mag showed no improvement. However as I was changing them over I thought one cable seemed to move around a bit so investigated and found there was an ordinary washer rather than the proper split brass washer holding the cable in place. Now I had these proper washers on the shelf, and I fitted the cable so what an earth was I doing. Anyway fitted the correct split washer and the replacement mag. JOY it worked a treat, no misfire on acceleration. So now I have to decide, was the loose HT cable the cause of the misfire or was my apparently rebuilt mag at fault? I guess its back to the garage tomorrow and refit my mag with the improved HT cable and hope. My only explanation is the gremlins in my garage have been up to a lot of tricks, what with the changed needle position, the missing split washer and now the dynamo on the single. Anyone got a cure for them?

[saltbox alf]

Hi Clive, been following your post, I am so glad it's back together and running. I suspect it's the loose lead rather than the washer, although the correct washer is best.
Possibly happening at a set vibration level causing the missfire (do they vibrate? Really!!)
Look forward to the update.

[clive]

Finally an update. Bike ran ok with a borrowed mag so I got some miles in but finally decided I really ought to sort my own mag out and gave the borrowed one back to force some action. New pick ups fitted, with new brushes, new plug caps, new plugs, new copper core HT cable. Magneto back on the bike (by the way how much easier it is to do the timing since I bought the AO services magneto points device, it allows you to do all the work from the one side whilst watching for the tell tale light to come on to say the points have opened). Bike started easily, off down the road and within 1/2 a mile it was misfiring at all revs, much worse than before, like it had deteriorated whilst sitting on the shelf in the garage or was it having a fit of peak because I had been using another mag?
Off it came for the nth time and having ordered the pick-ups from Bright Spark magnetos, I thought I would give their electronic condenser replacement a try before giving up and getting the mag rewound. Only £18 inc postage and it arrived the next day. Clear instructions on how to disconnect the old condenser on the internet, 20 mins to disassemble the mag following their clear guidance and about 10 mins to unsolder the condenser, solder the two wires together and seal in shrinkwrap. Fitting the Bright Spark gismo under the screw of the points carrier took even less time.

Mag refitted, carefully ensuring that this time I managed to avoid timing on fully retarded (its slack wire advance on a twin Clive!) and what a difference. Bike was pulling like it used to up to 75 at which point I get nervous as the steering goes a bit funny what with the knoblies front and back. However this long saga is now over, the engine is running and oiltight, so thanks for the help all and I thoroughly recommend the Bright Spark gismo

Better get started on one of the other 5 bikes languishing and waiting for attention, but I might just go for a ride first.

[Samuel]

(by the way how much easier it is to do the timing since I bought the AO services magneto points device, it allows you to do all the work from the one side whilst watching for the tell tale light to come on to say the points have opened)...
... and I thoroughly recommend the Bright Spark gismo

Hi Clive.
I offered to lend you one of those magneto points lights some time ago. They do make life much easier.
I also did the Bright Spark condenser swap and my G9 starts first or second kick.
Just trying to get the dynamo to behave now !
Sam

[saltbox alf]

Glad to hear you are back on the road Clive, my two bikes have Brightspark gizmo's and go well.

[clive]

Off the road again. These twins do seem to me to be picky, choosy and temperamental, whilst the singles seem to keep working for ever regardless of the abuse I give them. The left hand cylinder head on the twin has managed to sustain a rotated inlet valve seat and the quote from the local specialist to replace it was astronomical since it would apparently need a special seat to be machined as it was deeper than any stock item (and this is the company that supplies most others with the blanks)
So my question is how do you tell the difference between a 500 and 600 cylinder head, if there is a difference? I believe the exhaust pipes are the same size, but are there differences in the head. My parts list specifies different part numbers for the head and inlet valves for the 500 and 600 otherwise parts seem to be the same. So what am I looking for to establish the difference when I try to track one down? (wanted ad placed!)