Can anyone give me a crash course on tuning PSI Big Air Carbs

Nov 26, 2007
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Just bolted a PSI 990 in my CMX chassis, a project that I started 7 years ago but kids and life and such..... anyways got it in there and started up but have no idea what the dials and screws do on those carburetors, was told they are easy to tune with 3 adjustments. Any info would be helpful.
 

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Just bolted a PSI 990 in my CMX chassis, a project that I started 7 years ago but kids and life and such..... anyways got it in there and started up but have no idea what the dials and screws do on those carburetors, was told they are easy to tune with 3 adjustments. Any info would be helpful.
Don’t have any info for ya,sorry. But I do have a question. Does that ignition have a tps? If so how is it set up? Pics?
 

ez-ryder

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Nov 26, 2007
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Dawson Creek B.C.
I've never tuned something like this.
but I was under the assumption that this carb is similar to a lectron.
So maybe you can find a lectron expert.
maybe you can talk to lectron if PSI isn't any help.
 

slash

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Jul 22, 2008
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IDAHO FALLS 83404
Um there easy just crack open the jet screw turn the needle in or out to adjust fuel .
Start with the needle in the center all the way in all the way out back half way, you want 400 to 600 idle temp 1050 cruse 1250 WOT .
hope you have a EGTs set up first .
 
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