hashashan wrote: +/-1 turnout? You mean it is supposed to be nearly closed?
Yes! Anything more than 2 turns and you should start be suspicious ...
hashashan wrote: I turned it half way out ... that is about 3-4 turns from fully closed position. I guess this is not normal .....
No! Basically, you are allowing too much air/fuel mixture thru the idle circuit. And this circuit is in operation, to a greater or lesser degree, at ALL throttle openings, not just at idle. I'll add something about this below - see the paragraph with the **.
Also, Kev makes a good point. You can get a build-up of hardened fuel deposits on the top of the enricher jets. So, when you remove the enricher pistons, have a good look down the chambers that they come out of and make sure the top of the enricher jets are clean. They must be able to give a good surface for the rubber seal in the pistons to seal against. You'll easily see what I'm talking about when you get there.
hashashan wrote: ... and I will check the thing with the enricher seal in the next few days ... if that is the problem I owe all you guys a beer when u come to Israel :D
Well, let's hope this is all it is. Carbs are precision instruments, required to measure out finely balanced amounts of fuel and air while putting up with dust, motion, changing temperatures, crap fuel etc etc. So they do need looking after, especially at the age they're all at now.
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** Ok, back to the mixture screw 'problem'. The most common cause of this is a little difficult to explain, but here goes ...
At the entrance of the carb, i.e. the end that the air filter fits on to, you will see, below the throat of the carb, some small drillings. One of these supplies air to the idle circuit and, because it is rather small, it often gets partially blocked by fuel deposits. This is especially true with modern fuel which evaporates more quickly than the old stuff
.
These deposits can be very tough and hard to remove. Do NOT stick anything steel down the drilling. It is stepped inside and you could wreck it.
The best solution is to put the carb in an ultrasonic cleaner - the thing jewellers and opticians use. Otherwise, spray carb cleaner, possibly with a little help from a fine nylon or brass brush or wire,
can clear any deposits, altho' it may take some time.
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Anyway, try with the enrichers first and let us know how you get on ...
P.s. At some point, you may decide to simply send your carbs off to someone who knows what they are doing for a full overhaul. Steve Allen offers this service. Or you might decide to buy new ones. I see you were talking about fitting 40mms; but, unless you also fit Contis (or similar) silencers, you won't gain much. And, while you will gain some top speed, you will also lose torque at most riding speeds.
In many people's opinion, a better compromise is 36mm carbs - which Steve can supply, btw.
Ciao
Craig
