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 Post subject: idle jet question
PostPosted: Sun Sep 18, 2011 8:41 pm 
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WoodsBuggy Addict
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Joined: Fri Nov 30, 2007 4:03 pm
Posts: 3181
Location: leeds alabama
i have dual 40 weebers and my buggy smokes black on idle and if i rev up and let off so im guessing idle jets my motor is a 2221 and the idle jets that are in now are 50s what is suggested i should have in them :?:

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 Post subject: Re: idle jet question
PostPosted: Sun Sep 18, 2011 10:27 pm 
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WoodsBuggy Addict
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Joined: Fri Nov 30, 2007 4:03 pm
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Location: leeds alabama
anyone?

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 Post subject: Re: idle jet question
PostPosted: Sun Sep 18, 2011 11:42 pm 
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Joined: Sat Feb 24, 2007 12:02 am
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Location: Germantown Ohio
50's sound about right. How far out are the mixture screws? Have you taken the tops off and checked the float levels? Also what is your fuel pressure?


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 Post subject: Re: idle jet question
PostPosted: Wed Sep 21, 2011 1:47 pm 
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Joined: Fri Nov 23, 2007 11:27 pm
Posts: 496
Location: Chandler Az
LIke stated 50s sould be close, fuel pressure is critical as is float level.
Also make sure the needle and seats are not seeping fuel at idle making it rich.

Venturis are usually 2-6 mm smaller than the intake valve size.The smaller venturi the more bottom end torque.
Fuel pressure is critical. 2.5 psi.
Float level 10-11 mm. Start with 10.5 mm
Emulsion tubes F-11 are the most popular
Idle jets 1.6xs the size of the venturi.
Mains 4.1-4.3 xs the size of the venturi. a little rich is better than too lean.
Air 1-2 sizes larger than the main
1500 -2000 rpms is controlled by the idle circuit
2000-3000 is fed by the idles and the mains
idle jet size and float level are what you use to tune this rpm range.
3000-4000 is fed from the mains
4000-5000 from the mains and airs
acc pump jet use the smallest you can and still accerate. Adjusting the rod can make a significant change.

It seems to work ok for most engines with small to medium sized valves.


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