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

S
Nov 26, 2007
264
7
18
ND
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.

CF27B615-2AD9-476C-A98D-4B223D35F546.jpeg
 
U
Jan 24, 2018
10
11
3
47
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

Active member
Premium Member
Nov 26, 2007
194
34
28
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.
 
T

TheBreeze

Well-known member
Jul 23, 2008
1,970
518
113
41
Sussex, Wisconsin
 

slash

Parts Moderator & Chat Box Cop
Staff member
Lifetime Membership
Jul 22, 2008
3,060
1,224
113
64
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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