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[Scalyback]

Just to tie up the thread nicely, and after advice from the forum, I changed the recommended main jet from a 250 size to a 230 (I also have a 240 but not tried that yet.) Instant cure, Kevin runs at all throttle positions now.

NOTE:- always remeber that modern petrol is a little different, and an old bike will most likely need a slightly lower number main jet than recommended. (about 5% lower)


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REOC 15084

Tabellarius de verbis. Ostensor gaudium[/center]

[vince]

Hi scalyback, I found that my twin did not like NGK plugs as they used to cause pinking and sooting, try champion n5 and set at 20thou. Vince

[jefrs]

I haven't seen an Amal let alone a mono-block for a long time but I don't expect they've changed much. I may get some of the naming of parts wrong because I never learnt the right names -

The choke/cold-start slide should be raised for normal running, cable pulled tight at the lever, the lever's friction grip can let go and lower the slide as you ride, a spring pulls it down. You can get lfet hand and right hand levers so lever forwards is not making a lot of sense either way to me even with pictures (forwards on the bike direction or forwards towards you - tight or slack cable?); the cable pulls the slide up, lowering the cold start slide blocks the choke gap in the air slide, the thing that goes up and down on the throttle cable with the needle attached. Having to run with the cold start lowered indicates something is wrong.

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There is or was a throttle stop screw on an Amal (designs vary) that halts the downwards progress of the air slide, set this gap with an appropriate drill bit then set idle speed on the bypass/idle screw, set needle height (and jet size) by running the bike. The main jet does very little at idle so you can set idle without paying much attention to the needle at this point. This is basic set up, the starting point, assumes the jet is not blocked etc.



What bothers me is just one sooty plug. Fit new or known-good plugs. 25-thou is probably minimum gap, too small and they break down at high revs, too big and they won't spark. Check all spark electrics thoroughly, HT caps, HT leads, points (points wear the heel and the gap closes), condenser(s). Do you have rotor arm and HT cap. Used to clean the rotor blade by scraping on a kerb, not a good idea if you have some fine wet 'n dry handy.



Sooty plug indicates missing on that side so trace the HT back through to the distributor. Something one-sided and not common to both. Could be many things, hopefully just a duff plug. HT cap loose?

[Dennis C]

Jeff, for info the thread is a year old and been resurrected as problem now solved.

Vince I had the same problem on my Super Meteor Champion plugs sorted it.

Simon you are correct re the jet size all my old 50s 60s bikes now run a slightly smaller main jet.

[Scalyback]

It would have been more complete of me to explain further...



The sooty right side cylinder slowly sorted itself out, leading me to believe that the restoration had probably included an overhaul and the rings, whatever were still bedding in. I still had slight ignition problems and so with the mounting desperation of a bike in France, miles from any RE dealer or anybody that knew much about them, I went round the local garages looking for old spark plugs. I pooped in two RE recommended Lodge HLN, and the bike just sat up and went. now both plugs come out pinky tan (pink ceramic = kool).



But the most noticeable effect on smooth running was changing the main jet. So small... So simple, and yet it had been a problem that had kept me worrying about reliability. Now it's Super bike --- Scoff, off and away!



Your out of date, possibly Microsoft browser does not support the audio element.

[Scalyback]

Jefrs, thanks for the info anyway and the choke lever goes clockwise, so I keep it pointing towards me (cable operated), to keep the slidy thing up. That was another learning curve, no wonder I had initial problems starting, always turning the choke offto start!!! I don't use that lever anyway, just tickle the carb for a second or so, and by second kick, he's running. I don't give the MM any priming kicks, so no first kick start like Tornado does.

[Dennis C]

I bet you were popular, pooping in a lodge

[Scalyback]

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Vince, I set mine to the manual's suggestion 0.018-0.025, so about that.



After the success of the old plugs, news got around and the plugs on my wish list kept rolling in. It would be a little embarrassing to refuse them, but now I have rather more than I think Kevin will ever need.






Lodge HLN
K.L.G. FE70
Champion N-5
AC 45XL (pretty green stripes!)




I just about got everything sorted in the workshop now, and the Whitworth spannerium is full from 1/8th to 1W!






And for those of you who know me well and spotted the old telephone, yes it's wired in and working, but you have to talk very loudly at it, and the other end sound a but 'funny' and 1920's funny with it!.


So if you want to try your Meteor Minor with a pair of Champion N-5 and can't find any, let me know!

[jefrs]

I hadn't noticed the thread was that old as I only looked briefly at p.1. Oops!

I have noticed some chaps set the air-slide on the cable when it supposed to land on a stop, usually a screw (set gap with small drill bit as gauge). The slide descends on a spring when the cable goes slack, you can much about the carb by how well the air slide descends.



When all else fails, read the manual - If you have upgraded the ignition in any way then a slightly bigger gap will provide a fatter spark. The reason for small spark gaps was lack of volts.

25-thou is 0.635mm for those of us who can't think in inches now; the "modern" plug gap is 0.7-0.8mm i.e. 30-thou and more suited to electronic ignition.



Likewise I never used the cold start slide, I think I had the screw atop the lever done up so tight it would not move.

[Thack]

That cold start slide in the Mk1 is an appalling bodge. Its effect rises rapidly with throttle opening and renders the bike undriveable at anything above a quarter throttle, and at that point it's so rich you risk hydraulic lock (exaggeration for effect).



Amal should be ashamed of themselves for such a crap solution. Not to worry - for most bikes a tickle is enough, combined with some intelligent use of the throttle for the first couple of minutes.