pilot jet bung

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Thomas
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Bike owned: Gpz900r
Location: Barnsley, Uk
pilot jet bung

Post by Thomas » Sat Mar 05, 2016 10:41 am

Hi guys, just wondering if the bungs that go into the pilot jet hole are solid and completely block the tube up, missing three from my carbs but can easily make some more. Just need to know if they block the pipe up or let some fuel through.

lknbandit400
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Re: pilot jet bung

Post by lknbandit400 » Sat Mar 12, 2016 3:35 am

Thomas wrote:Hi guys, just wondering if the bungs that go into the pilot jet hole are solid and completely block the tube up, missing three from my carbs but can easily make some more. Just need to know if they block the pipe up or let some fuel through.
The plug blocks flow. If you look carefully there's a bridge from the main jet casting to the pilot jet casting. That's where the pilot gets its fuel.

You said you can make some?

Thomas
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Re: pilot jet bung

Post by Thomas » Mon Jan 02, 2017 6:18 pm

Yes, i can make them. What i need to know is how much of the hole they block, do they compketly block the pipe and allow no fuel through?

ventYl
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Re: pilot jet bung

Post by ventYl » Mon Jan 02, 2017 6:28 pm

They block the pipe completely from downside. Yet there's another thin passage (as already mentioned) at side wall from direction of main jet so you have to make plugs having correct depth to not blocking this auxiliary hole as well. It should be sufficient not to make them deeper than original ones and it should be fine.

The rason for them is mostly unclear for the public. Some say that they have rough idle without them, some say the idle is the same w/ and w/o them. Some say that it is due to low displacement but then similar displacement bikes with similar carbs (or even same carbs of different subtype) did not have these plugs mounted from factory. Some say it prevents reverse flow of fuel under full load (or something similar). We only know for sure his name is Stig :)


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