UFO
#1
12-11-2000, 10:50 PM
Join Date: Nov 2000
Posts: 192
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#2
12-13-2000, 12:02 AM
I did some of the initial flow bench testing on the U.F.O. for Thunder Products
The idea was to get a round slide carb. to perform like a flat slide by covering up
the empty cavity under the slide. This helped to reduce the turbulence under the slide and
provide better atomization for the fuel. What we found was the flow (cfm) was nearly equal to
the flat slide but with a much greater pull on the fuel signal. In later testing on motors
they found that at an idle there was too much draw and had to make modifications to the UFO
and needle jet. There is a good article about them on snowmobile world.
http://www.snowmobileworld.com/features/ufo.shtml
I have used the on my '97 polaris storm and have had great results.
Porting and head work would not be needed to realize the benefits of the UFO's
You can also check out:
http://www.thunderproducts.com/u_f_o.htm
Good luck!
GP Engineering
gp@gcnet.com
The idea was to get a round slide carb. to perform like a flat slide by covering up
the empty cavity under the slide. This helped to reduce the turbulence under the slide and
provide better atomization for the fuel. What we found was the flow (cfm) was nearly equal to
the flat slide but with a much greater pull on the fuel signal. In later testing on motors
they found that at an idle there was too much draw and had to make modifications to the UFO
and needle jet. There is a good article about them on snowmobile world.
http://www.snowmobileworld.com/features/ufo.shtml
I have used the on my '97 polaris storm and have had great results.
Porting and head work would not be needed to realize the benefits of the UFO's
You can also check out:
http://www.thunderproducts.com/u_f_o.htm
Good luck!
GP Engineering
gp@gcnet.com
#4
01-15-2004, 01:55 PM
UFO
the idea behind the high fuel consumption when using UFO's is that when you back off the throttle the needle jet draws alot of fuel and cool the motor
saving it from melting due to lean out.
this is a safety built in by the manufacturer,so if you want to run a small needle jet you will patch up this fuel consumtion problem but risk part throttle burn down(that is if you ever go slow down the trail).
IF you use the right main jet (not too lean) you can run the proper needle jet by drilling out the hole in the UFO that the needle itself goes through,not sure of the size for a small carb but I did 5/16 on my snowmobile 38mm carbs,this will reduce the vacuum signal to the needle jet and reduce fuel consumption.
NOTE on some of the bigger carbs 38 to 44 you cant get a small enough pilot and or needle jet to fix problem so you need to do this mod to the UFO or continue with the high fuel consumption
my 2 cents
saving it from melting due to lean out.
this is a safety built in by the manufacturer,so if you want to run a small needle jet you will patch up this fuel consumtion problem but risk part throttle burn down(that is if you ever go slow down the trail).
IF you use the right main jet (not too lean) you can run the proper needle jet by drilling out the hole in the UFO that the needle itself goes through,not sure of the size for a small carb but I did 5/16 on my snowmobile 38mm carbs,this will reduce the vacuum signal to the needle jet and reduce fuel consumption.
NOTE on some of the bigger carbs 38 to 44 you cant get a small enough pilot and or needle jet to fix problem so you need to do this mod to the UFO or continue with the high fuel consumption
my 2 cents
