Dynojet jet sizes

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tfr125
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Dynojet jet sizes

Post by tfr125 » Fri Aug 10, 2012 9:57 pm

Does anyone know if Dynojet size their jets different to the std Keihin ones??

My NC29 race bike has 108 (Dynojet) mains in it but is still running rich (tailpipe was still black and sooty even after an 8 lap race at Olivers Mount)

The bike has GF airbox with ram air, K + N filter, tuned motor and Beet copy exhaust.

I was thinking of getting one of Yakama's HRC carb kits, but the jet sizes in these are massive - are these designed for running with no filter?? I would prefer to keep the filter as the road circuits tend to be a bit dirtier than closed circuits.

Cheers

Tony

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Drunkn Munky
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Re: Dynojet jet sizes

Post by Drunkn Munky » Fri Aug 10, 2012 10:10 pm

Yes dynojet jets do flow more than Keihin, its been covered a few times and i think theres a chart somewhere.

As for yakama's HRC kit dont quote me but im sure your need to run a full HRC setup for it to be of any use.

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Re: Dynojet jet sizes

Post by Yakama » Fri Aug 10, 2012 11:12 pm

The HRC set up I'm selling is designed to work with the HRC airbox (which I assume you have if you have a GF copy) and HRC CDI and an HRC exhaust. It comes with a range of needles and so shoulw suit various set ups

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Re: Dynojet jet sizes

Post by Yakama » Fri Aug 10, 2012 11:24 pm

And sorry yes is designed for no filter though I'm sure sone sort of thin filter could be used without compromising the setup too much
Last edited by Yakama on Sat Aug 11, 2012 10:25 am, edited 1 time in total.

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Re: Dynojet jet sizes

Post by GF Racing » Sat Aug 11, 2012 1:23 am

Simply fit the HRC air filter set up ... and clean out the air box everyday.

Check the air corrector blanks are still in place.

Or carefully clean and very very lightly re oil the KN .. use KN cleaning kit.

108DJet should be good .... very very occasionally we have used a 106 on a Ram Air set up ... with air corrector blanked.

Hope that helps.
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matt69
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Re: Dynojet jet sizes

Post by matt69 » Sat Aug 11, 2012 9:57 am

[quote="tfr125"

My NC29 race bike has 108 (Dynojet) mains in it but is still running rich (tailpipe was still black and sooty even after an 8 lap race at Olivers Mount)

Tony[/quote]

Unless you are running Avgas which is a leaded fuel your exhaust will alway be black and sooty, this is the way unleaded fuel burns. My bike has been set up on a dyno and the fueling is nearly spot on and the exhaust is black and sooty. I have however found out where I can buy avgas from a bowser wit a credit card after hours. :grin:

Matt

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Re: Dynojet jet sizes

Post by matt69 » Sat Aug 11, 2012 10:05 pm

The plugs are a different story though, check them.

Matt

tfr125
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Re: Dynojet jet sizes

Post by tfr125 » Sun Aug 12, 2012 11:29 am

Thanks for all the advice guys.

I am used to running two-strokes and have a bit of experience of using unleaded and avgas fuels. The two stroke tailpipes with unleaded were always black compared to the avgas , but the pipe on the NC29 is not only black but has soot all around the inside and outside of the tailpipe!! I will have a look at the plugs though and see what they look like.

Probably the easiest solution is Graham's suggestion of the HRC filter (am I right in thinking this is a standard filter with all the paper filter removed leaving just the mesh??)

Thanks again

Tony

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Re: Dynojet jet sizes

Post by GF Racing » Sun Aug 12, 2012 1:24 pm

Tony,

Correct re the HRC filter set up ... I still remember ordering 2 new some years back from Padgetts ..... quite a shock on price !!!

Be careful not to break any of the mesh retaining "rivet" points.

Cheers

Graeme

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