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My bike seems to run really well...once it's started.

It went into a dealer for a service pretty much as soon as I got it (so it has new plugs, oil etc etc), so I dont have much recollection of how it ran before - but im sure it didnt take this long to start.

I've since fully cleaned the carbs - no real difference.

I had it out on a wee run an hour ago (where the bike performed faultlessly...once started) and have just taken the following reading (and video) after letting it all cool down.

Battery when off; 13.01V, battery when running; 14.75V, also, (but probably irrelevant) once off again the volts drop from about 13.5v back to 13v over the course of a minute or two.



Does anyone have any thoughts? Im truly stuck on this one.

the Sound quality is bad on that video so cant really hear how it initially sounds when started.

How does it start after a run? As in, switch off after a 10 mins of riding, and then back on again and start it. how about then?

Are you using any choke at all? I know its hot weather at the moment but i would assume not.

How long ago was the service done?

RedexRobB wrote:the Sound quality is bad on that video so cant really hear how it initially sounds when started.

How does it start after a run? As in, switch off after a 10 mins of riding, and then back on again and start it. how about then?

Are you using any choke at all? I know its hot weather at the moment but i would assume not.

How long ago was the service done?

If I switch it off, then start it after a couple of seconds it will generally fire up much much quicker. After 10 minutes of it off, it will probably behave similarly to that video, as that was only taken after an hour of riding.

Once started it sounds nice and smooth (the garage also balanced the carbs).

No choke at all.

It was serviced about 3 months ago.

Edit: It also has fresh petrol.

i would try starting the bike with a little bit of choke, then with full choke - this will tell you if it needs extra fuel or not at startup.

if it needs choke try turning the pilot air screws 1/4 or 1/2 turn clockwise each and see if this does anything, if it wont start at all, i.e. is worse, with choke, then try turning the mixture screws 1/4 or 1/2 turn counterclockwise

clockwise, means that you are screwing the screw inwards, counter clockwise means that you are screwing out.

Heres another quick video I took after reading Rob's post. Its about an hour after the first one, and the bike is warm-ish (plus its about 26 degrees outside)



Banner - the bike's behaviour is actually slightly odd when the choke is introduced into the picture.
As I engage it slowly, it will sometimes work and bring the revs 1500 rpm, whereas other times it will all but stall the bike ...maybe time for video number 3?

When I had the carbs out I did notice the carb spring was looking a bit sorry for itself and - slightly slack and deformed, but still had the full range of movement once all connected up.


The idle screw is set as per the manual (1 and 3/4's out I think) which seems about right.

1 and 3/4 seems rich to me, i would turn out all the air screws in 1/4 increments and see if the bike behaves better then...you can always put it back to 1 and 3/4 if necessary.

you got any mods on your bike, or is it stock jets and needles with original airfilter, downpipes and can?