Carb question

theo125

New member
Joined
Feb 26, 2009
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183
Age
56
Location
East Greenbush Ny
Guys,
I have a quick question. I have an extra set of carbs that the previous owner had taken off because it would not run right. After disassembling and seeing all the varnish I knew why. Anyways, the line that runs from the bowl to the body had a small ball bearing at each end in the line by the nipple. I have never seen this before. What the heck are they for and why are they in there? I would think they would plug the lines. Maybe when the lines are new they would move back and forth but now they are locked in place.
 

can you post a pic? Sounds like some type of anti-back flow device. does the line carry fuel or air?
 
sounds like you have a set of power jet carbs and somebody eliminated the power jet circuit by pluging the fuel line. thats ok as long as you richen up the main jet to compensate.
 
theo125 said:
Why would someone do that?

It's a performance modification to try to eliminate mid range inadequecy(sp?) issues (At least in Harleys). Is there a fitting on the carb that looks like the plugged line would go to it if the bearing like object was removed? Or maybe a plugged hole that looks like it wasn't designed into the carb? Once again, pics would be a big help here.

Here a link to the Thunder PowerJet website. You should see a pic of a Thunder Powerjet modified carburetor and an explanation of how the power jet works:

http://www.thunderproducts.com/thunder_powerjet.htm

Home this helps you figure out if this is what it is! ;)
 
Last edited:
OK making a little more sense. The carbs on my sled now, don't have this set-up. It looks like it would indeed block the line.
If the ball bearings were removed the fuel would flow from the bowl to the side of the carb.
 
There were numerous issues with the "Power Jet" carbs used on the VMAX 540s + the early Exciters. One of the solutions was to disable the "Power Jets" by placing a "BB" in the fuel line that runs from the bottom of the float bowl[the jet that meters these was a round headed jet right at the bottom inside of the float bowl around a #200] to the power jet on the carb throat. This was all well and fine but you have to ensure the jetting was richened up accordingly!

IMO the power jet carbs themselves need to be replaced with the later VM38s as the jets are relocated from the bottom of the float bowls to the bottom of the needle jets.
On my old Improved stock VMAX 540 I installed a pair of carbs that came off of a Polaris that had deeper float bowls and long 247 series needle jets, that had the main jets right on the bottom of the needle jets. By doing this, I elliminated misterious melt downs that had been occuring and I could then jet down for max "Reliable" power.

JM.02c
 


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