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By Andy C
#90449
Finally took the 612 out last night after taxing it, normally I would have started riding it around March time.

Anyway this is the first time I have ridden it since fitting the Amal Premier carb and going up 1 tooth on the gearbox sprocket.

I am pleased to say that I am very happy with these mods, the motor feels more responsive than it was with the old worn out Amal on it, and the extra tooth on the gearbox sprocket makes for more relaxed cruising, it does not seem to have affected acceleration.

The only issues I have are that the clutch is slipping a little under hard acceleration, I just need to turn the clutch spring screws in a couple more turns, I really must make a note of the screw positions next time I have it apart. Bob Newby clutch by the way and does not normally slip.

The other issue is that the lever that operates the choke keeps rotating around to close the choke while you are riding – if you tighten the screw to stop it turning you cannot operate the choke.

I am seriously considering drilling a small hole in it to suit a small R clip (which I can keep on a lanyard attached to the lever) to stop it rotating.

The lever does not seem to have anything to prevent it from moving under vibration – seem to remember that some of them have a large diameter wavy washer.

Finally, the battery in the bicycle speedo was nearly flat so it was showing my speed as anywhere between 65 & 118 MPH most of the time. I rely on the bike speedo as the OE speedo really is just an ornament I call is the “approxometer” battery now replaced.
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By Haggis
#90450
All my levers for carb or magneto have a large wavey friction washer fitted. Still check their position every 10 minute when riding though. Good to hear it's now running well.👍
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By stinkwheel
#90452
Yes, should be a wavy anti-shake washer in the choke lever. Maybe it's snapped and fallen out?

I put a fairly thick rubber washer in mine which seems to grip better but still allow it to turn.
By singleminded
#90492
The choke lever closing has come up before, I think, but having been working on a 1957 Matchless, I have noticed what I believe to be the fundamental problem with the choke levers available today.

The thread on the top nut is much finer on the old levers on the Matchless compared with the new 'repro' stuff. As a result, the new ones are far more likely to 'unwind' than the originals.

The one on my Bullet does it all the time. If I tighten it sufficiently to keep it open, it will work for a couple of starts, but then the screw can be seen to come loose as the lever is turned anti-clockwise.

I think that a wave washer is essential to minimise the problem and perhaps loctite on the centre screw.
By Daiwiskers
#90494
In the past I have used course wet and dry between the lever and top plate two sheets rough sides out
At the moment I am trying tyre bead sealant it seems to be working but the bike is still locked away in the garage so time will tell
Thread loc on the screw sounds like a good idea I am off to add some now(well very soon)

Take care all Dai
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By Wheaters
#90499
Daiwiskers wrote:
Thu Jun 04, 2020 8:33 am
Thread loc on the screw sounds like a good idea I am off to add some now(well very soon)
Loctite "blue" is best - it does the job but unlike some other products you can still remove the screw later without rounding the slot....

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