NC30 Emulstion Tubes and Needles

[CMSMJ1]

To stick a tuppence worth in..I'd agree with phil (with a kiss)

Try it with smaller mains..

Or, take the airbox lid off...see how it likes it. It won't like it at all.

I am not a fan of chopping the base plate or snorkels etc - the engine is a pump, it does not need air forcing down it's throat as it breathes in the air perfectly well.

FWIW - my race bike has a full system, standard airbox and filter, HRC air tray with base plate flaps and snorkels in place and runs 120s all round. It fuels lovely.

Also - can you explain the reply to Cammo with the T piece drawing? What does that mean? I don't get it (as I am thick perhaps!)

[phil x]

Hmm, interesting.

You say that it's only rich in the mid range......
So, you don't count a CO reading of 11-11.5 at 14000 rpm as rich then

You should be looking at readings of 13-13.5 for optimum power or the 14+ for economy but feel free to soldier on.

There is lots of knowledgable folks on here but if I have learn't one thing - everyone is obsessed with making the bikes run richer

Phil

[porndoguk]

To stick a tuppence worth in..I'd agree with phil (with a kiss)

Try it with smaller mains..

Or, take the airbox lid off...see how it likes it. It won't like it at all.

I am not a fan of chopping the base plate or snorkels etc - the engine is a pump, it does not need air forcing down it's throat as it breathes in the air perfectly well.

FWIW - my race bike has a full system, standard airbox and filter, HRC air tray with base plate flaps and snorkels in place and runs 120s all round. It fuels lovely.

Also - can you explain the reply to Cammo with the T piece drawing? What does that mean? I don't get it (as I am thick perhaps!)

This



i remove the emulsion tube attached a longer hose to one of the slides vaccum hoses (the ones that connect to the subfilter, and blew to watch, the needles draw out which are as i says oposite T to the emulsion and not sitting in the the emulsion tubes as we all expected?)

[Cammo]

You say that it's only rich in the mid range......
So, you don't count a CO reading of 11-11.5 at 14000 rpm as rich then

You should be looking at readings of 13-13.5 for optimum power or the 14+ for economy but feel free to soldier on.

Yeah that was the point I was trying to make - it's too rich everywhere according to that graph. The midrange is obviously so rich that it's affecting the burn, everywhere else is just damn rich!

[porndoguk]

what size jets should i put in then?

[reverse cylinder jim]

As ive mentioned before mine runs beautiful all the way through the rev range running 115 fr 118 r. No flat spots just pulls and pulls.
Put out 63bhp last time on the dyno with half system, k and n, drilled slides and an extra washer under the slides.
The dyno operator said it was still on the rich side though.
James

[porndoguk]

As ive mentioned before mine runs beautiful all the way through the rev range running 115 fr 118 r. No flat spots just pulls and pulls.
Put out 63bhp last time on the dyno with half system, k and n, drilled slides and an extra washer under the slides.
The dyno operator said it was still on the rich side though.
James

cheers jim, will try that and come back with results,
i have 118 and 115/6 keihin ones in the garage i will check later but i wont be fitting them until i come back from holiday as i cant bare to strip the bike down again this week. its pissing me off as you can imagin.

[porndoguk]

RICK O NEEDLES HERE :D

if the mrs allows it i may, rejet and re needle this evening

[Neosophist]

Just re-read through this thread.

Something that comes to mind is that you have drilled out the slides. Are they also stock carb springs?

If the hole is too big the slides may rise too fast when the pressure is changed (such as cracking it open) which could be causing your richness in the mid-range. It'll be really rich...

You can try this without removing the carbs but if you take the tops off and get the slides out, clean them and put electrical tape over your hole and make a much smaller hole using a pin / needle and see if that makes a difference.

Only thing I can thing of why it goes too rich on pretty much ok jetting.

[porndoguk]

Just re-read through this thread.

Something that comes to mind is that you have drilled out the slides. Are they also stock carb springs?

If the hole is too big the slides may rise too fast when the pressure is changed (such as cracking it open) which could be causing your richness in the mid-range. It'll be really rich...

You can try this without removing the carbs but if you take the tops off and get the slides out, clean them and put electrical tape over your hole and make a much smaller hole using a pin / needle and see if that makes a difference.

Only thing I can thing of why it goes too rich on pretty much ok jetting.

stock springs yes.

only drilled them to 2.5mm and the drill bit will probally be 2.3mm any way, most bits are .20mm under size.

gonna try the needles and down jet to 118 x 115or116 depending on what i have,