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nc30 120 all round jets - common? - now with video link

Posted: Wed May 12, 2010 7:12 pm
by pugparcels
i have taken a punt on cheap set of carbs from ebay, they looked very rough from the pics & what arrived in the post, however the interals are immaculate. the needles have had the extra washer added & the jets are 120 all round.

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is 120 all round a common setting? i have a laser race can & a dual foam filter and she is very rough at 4 - 7 k, i have standard jets in my import ( i have not tried this with the original honda filter which i think will be better )

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as this has 120 all round & the needles have been raised ( the sliders have not been increased to 2.5mm ) would we guess that the very rough spot 4 - 7 k would be better?

i know the only way is to try but would like to get an idea of what to expect before starting! ;)

Re: nc30 120 all round jets - common?

Posted: Wed May 12, 2010 7:16 pm
by CMSMJ1
I'd start with the filter mate..

120 is common enough from people fettling the carbs and following the generalised settigns on here and other places.

Take the washers out - see what it goes like then!

Re: nc30 120 all round jets - common?

Posted: Wed May 12, 2010 7:44 pm
by pugparcels
first option will be my existing carbs with standard jets & original oem filter.

if thats no better...

'new' 120 jets all round with oem filter and dual foam to see which works better

if that is still not a major improvement...

at least i have have both options now needle wise, can drill the extra slides to see if there is any difference there and i have a small selection of jets to play with.

i am guessing a dual foam filter would be better on a race type of bike or highly tuned, full race system etc?

Re: nc30 120 all round jets - common?

Posted: Thu May 13, 2010 12:47 pm
by superlite
Do those 120 jets have a make or symbol stamped on the side? Unusual that they have the number stamped on the top (and look silver in the pics?). Thought they were dreaded Dynojets at first.

120s all round should be fine though.

Re: nc30 120 all round jets - common?

Posted: Thu May 13, 2010 2:12 pm
by pugparcels
all they say is 120 stamped on the top as you can see in the pics, they are brass and seem like new, there is no screw driver marks etc, the float bowls are as if they are new so clean it is unreal. all of it is so clean inside!

the other interesting thing i have just found, the diaphram needles dont look standard...they have 6 adjustable heights operated by a e-style clip. in the carbs they had also had an extra washer added.

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ther are no markings what so ever on these and i know they do not look like my needles in the carbs at home?

Re: nc30 120 all round jets - common?

Posted: Fri May 14, 2010 12:44 pm
by Old Painless
Adjustable needles from a dynojet kit ?

Re: nc30 120 all round jets - common?

Posted: Fri May 14, 2010 12:56 pm
by superlite
Doesn't look like a Dynojet needle - the grooves are machined differently and the tip is quite blunt in comparison.

Whatever they are, I'd turf them. It's not worth the headache setting them up I reckon.

Burdiken (spelling) needles anyone :oops:

Re: nc30 120 all round jets - common?

Posted: Fri May 14, 2010 1:14 pm
by pugparcels
i managed to try the 120 all round jets last night in my carbs, only on tick over though as it was 9pm by then and the kids were in bed. she ran alot better with and with out choke no splutterting that i some times got with the originals from starting ( which were actually 110 all round not 115/118 )

i am going to try her again tonight so i can get here warm and run through the revs a bit more to see if she is still fluffy 4 - 7k ( still have the original & a dual foam so will try both options as well )

if she is still fluffy i will try the extra washer under the original needles, if this is no better then i may look at the adjustable needles to see if this is any better but hopefully washers under the needles will be the last thing i have to do and i may just chuck the adjustable ones on to ebay. someone would buy them.

will let you know how i get on tonight.

Re: nc30 120 all round jets - common?

Posted: Fri May 14, 2010 1:40 pm
by Old Painless
Putting an extra washer under the needle is much the same as lowering the needle clip on the adjustable needle. Im sure you know but i thought i would put in my 2 cents just incase. Does depend on the shape of the needle though.

Good luck. :plus:

Re: nc30 120 all round jets - common?

Posted: Fri May 14, 2010 2:03 pm
by pugparcels
we have been given a hd ready hard disk camcorder type thing that is you 'tube ready' as a wedding gift from my mum and dad last weekend so i will film the different attempts so it will be easier to look back and see which seems best.

if i can do it with out issue i will load the findings on to the thread.

i can change the needles / add washers with out removing the carbs.....cant i?