is a bigger jet needed when porting manifold and exaust, increasing air flow

069Toolman · Nov 12, 2012

A quick question, should i enlarge the jet if i have increased the airflow through the head. I Have increased manifold diameter with dremel and roughly ported out manifolds where they meet the head.

thanks in advance

069Toolman · Nov 12, 2012

if so what size jet and i am at 450 metres above sea level.

Cheers

Venice Motor Bikes · Nov 12, 2012

You won't know if you need a bigger jet until you actually ride the bike.
Re-jetting isn't always needed just because you changed something on the engine.

I explained a little bit of how to tell the right jet size in this thread... http://motorbicycling.com/showthread.php?p=439187#post439187

Carlbaker · Nov 22, 2012

But its feels very nice while riding a bike.

Carlbaker · Nov 22, 2012

Oh its good that you have reached at this level.

Carlbaker · Nov 22, 2012

But I'll suggest that you should not enlarge the jet even if you have increased the airflow through the head.

maniac57 · Nov 24, 2012

These kits are usually too rich to start with so I doubt you will need to rejet with these modifications.

CTripps · Nov 25, 2012

Most likely you'll just need to play with the needle's clip until it runs the way you want it to. Move the clip down for richer, up for leaner.

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is a bigger jet needed when porting manifold and exaust, increasing air flow

069Toolman

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069Toolman

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Venice Motor Bikes

Custom Builder / Dealer/Los Angeles

Carlbaker

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Carlbaker

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Carlbaker

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maniac57

Old, Fat, and still faster than you

CTripps

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