Carb jetting question

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Carb jetting question

Postby Joene » 16 Feb 2010 17:14

Who can advise me on a jetting set-up for my Dellorto PHBH 28 mm carb ?
engine is a (prepared) SIL200 with a MUGELLO 200cc V3.0 cylinder combined with a scootrs exhaust

needle= X7 2/3 clip ?
main= 135 ?
pilot= 55 ?
slide 50 ?
atomiser= AV264 ?
needle jet= 300 ?

Thank you, Jeroen
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Postby Joene » 25 Feb 2010 16:16

nobody ? [:(]
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Postby TheSeeker » 25 Feb 2010 16:57

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Joene</i>

nobody ? [:(]
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Given the extremely expensive repercussions from giving incorrect advice I doubt anyone will give jetting advice unless they have 100% exactly the same setup.

From what I can see you need to start rich and work backwards. Big atomizer, large number of clips, big main jet.

If it starts you ride it a bit and see what happens. I'm doing the same at the moment. When the weather is good I do 5 or 10 kms, listen to the engine, note the throttle responses and at the end of the ride see what the spark plug looks likes. Black and oily too rich, light brown ok, white and crusty too lean.

So far I find I have it too rich, it will start 3rd kick and stalls when I give any gas in the first 30 seconds of running but after that it goes ok. I'd prefer to be cautious rather than have it seize or hole the piston.

I think to only thing to do is start like this and see what happens.

Ben

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Postby TheSeeker » 25 Feb 2010 17:08

Have you asked on scooterotica? They have a sticky thread for jetting :-

http://scooterotica.org/forum/viewtopic.php?f=9&t=14

Ben

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Postby irish john » 25 Feb 2010 17:18

Strange question since the scooter was jetted yesterday???
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Postby fajes » 25 Feb 2010 19:42

he's a strange boy, John, that's all...[;)]
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Postby TheSeeker » 25 Feb 2010 22:43

That's what I forgot to say. You can try to work it all out for yourself and take weeks of trial and error or pay a professional who knows what they are doing toot sweet.

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Postby irish john » 26 Feb 2010 10:22

Its mostly dialled in now but will probably need slight main jet changes after its been run in.

Dellorto 28mm/scootRS pipe/Mugello 200 V4/easy breath air filter.

Atomiser AV266
Needle X7, second leanest setting
Slide 40
Pilot jet 55
and for the moment but this needs to be monitored. Main jet 125
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Postby Joene » 26 Feb 2010 13:13

sorry for not having updated my post [V]
the question was posted before John indeed jetted the carb

I'll give the LIS a good long test tomorrow when I pick it up again at lambrettafinder. But I trust and I know now already that John did a great job. Thanks ![:)]
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Postby irish john » 26 Feb 2010 14:05

its still a bit rich but its the best i can get it with the time i had with the engine.
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