Forum

[Scalyback]

[center]



Twin Dilemma!

the Meteor Minor has points, a new (looking) distributor, NGK resistor caps and NGK B6ES plugs, a single Amal Monobloc carb. (correct type for engine number) The right cylinder burns very rich. what should I be looking for?



here are the plugs, let is left cylinder when sitting on bike.








I switched the plugs in some desperate hope that it might work! I guess that would be too easy! Are we looking for loss of compression, or maybe air getting in the good side, with the amal set to rich to keep that cylinder happy?



it certaily has less power that tornado, my bullet, he will do riverhill at 50NPH. Kevin the meteor only make about 40MPH in third.




Help. Thanks










Tabellarius de verbis ostensor gaudium

[apparently lucky eddie]

If the ignition side is looking new and good then is she burning oil on one pot? Rings, valve guides all ok etc?
Also never discount the problem of snide NGK's. I've been caught twice with my Triumph, missing on one pot only, changed the plug for a new one,same problem, and eventually cured the problem with a pair of new Champions. Which was what should have been fitted in the first place.

[Gwilly]

Oh dear, problem indeed. Lack of power is a clue, perhaps a cold compression test to each cylinder may be revealing.

See if it can be improved with a drop of oil down the bore.. If its a valve then that won't make any difference..

Would certainly check manifold gaskets and any holes/splits in the manifold itself.. Carb flange distortion, tight tappet, usual suspects..

[Bullet Whisperer]

Get rid of the resistor plug caps for a start !! Ordinary plugs and ordinary plug caps work best on older machines with conventional ignition systems.

[Chris Tindal]

Can't comment on the plugs, and this isn't a solution to your issue. A friend and I have done some extensive road miles comparing his meteor minor with my 500 iron bullet. On the twisty back roads the bullet has the edge due to the low down grunt of the big single. Also up hills, with enough momentum, the bullet can easily leave the twin in equivalent gears. The twin feels quite slow at first but it needs plenty of revs, even though initially it feels quite strained. As soon as we hit long straights the twin comes into its own and above 60mph leaves the bullet behind, smoothing out and feeling relaxed at 65-70 whilst my bullet is over stressed. They are different bikes with different characteristics.

[Winkie]

The offending plug looks sooty rather than oily. As has already been said, start off by putting different plugs in. Last year I spent a fortune having my AJS650 engine rebuilt professionally but it persisted in starting and running on one cylinder, with one plug looking just like yours. The plugs were new NGK's. I bought a couple of old stock Champions and the cure was instant with firing on both and both plugs about the same colour. I read somewhere that modern plugs do not self clean like old ones used to, and this sort of problem is not uncommon.

[Dennis C]

I agree it looks sooty not oily, easy things first non resistor plug caps and Champion plugs. If that doesn't cure it look for manifold air leaks and check compression. Then it's head off time.

[RoSy]

Valve clearance ok?

Get some really good HT leads and plug caps, and if you think the coil (s) are faulty get some new ones. A weak spark will cause this every time and throw you off in completely the wrong direction, and check condenser or get a new one. All worth it for what it will cost.

[Scalyback]

[center]

Thanks all, the plug is sooty.



I will try to get a couple of Champion N5 plugs (originally NA8 before renumbering )


My book also recommends :-

KLG FE70

Lodge HLN



Should I keep an eye out for these as well?



I will see if I can get copper cored ignition cable, non resistor plug covers, check the condenser and also the points.



I re gapped the points and it runs a little better, but quite often on slow tickover, it sounds less like a twin and more like one and a half bullet engines. I mean that every other thump from the exhaust sounds a little quieter? but the bike seems to pull ok, but i have no experience of a brit twin to compare whether the power is ok or low?



On kickover, the compression seems matched as I can't tell which piston is compressing, so that may be a good thing. Have no compression tester, My friend used to use 3/4 inch ball bearings. take plugs out, balance ball bearings on plug holes and kick once, hard! If they shot upwards about the same height, then all ok. I won't be doing that to poor Kevin though!



the tyres are recommended 18 PSI front, 24 PSI back, but they came with 25 front and 34 back which seems ok, so will keep them at that, unless told otherwise.

OH! the pics... nearly forgot...







although a nice fuel tap, I am changing foe the correct pattern which had a hexagon to push and also a small reserve lever to twist. The existing one does not have a reserve, only a 'run out and walk' system.




Seriously, I spent time with the points the other day, and then I find this inside two layers of bags in the toolbox, all connected up. Had assumed it was a rectifier of similar. Does this only replace coil (and maybe condenser)?






Below is a way to support a saggy air filter element! I will leave it as I found it as it works!







There is much more for me to sort out and explore, but I really love this bike!






All new looking, Amal, distributor, fasteners, castings, yay! Nearest thing to a brand new 1959 motorcycle!

Tha nks again for all the help, I seem to be on the curve of learning again!

[Adrian]

You have points-assisted electronic ignition fitted to Kevin, sort of a half-way house! It doesn't replace your points and coil system, it's an add-on. To work at its best it still depends on the contact breaker assembly and the advance/retard mechanism being in good nick and properly adjusted. I'd be tempted to lose it in favour of a Pazon Sure-fire or Boyer Mk4, or even a nice SR2 or K2F magneto.



http://boyerbransden.com/IDunits.html



If you haven't already got copper-cored HT leads fitted, it's easy to find on the internet, and our hosts sell both resistor and non-resistor pug caps.



A very quick subjective test for the relative compression is to try kicking over with alternate plugs removed, if one side is easier than the other then the top-end needs investigating.



A.