Hi, im new to this site and also to my recently bought nc30, been spannering on bikes for 17 years though. My bike is a 91 nc30, runs an aftermarket (full stainless) 4 into 2 into 1 it has a 'Posh' de-restrictor and kmh to mph converter in line with the speedo cable. The air box is un-modified, running standard filter, the very first job i did was strip clean and set the carbs up as standard. It came with 115front 118 rear mains fitted. The bike runs sweet as a sweet thing NO flat spot and rides really nice (im impressed!!) I want to drill the slides for better throttle response, I will be really gutted and anoyed if this modification messes up the fueling and causes ANY misbehavior though. Does this mod have any failings at all? As its unusall to have gains with out loses else where. Many thanks. Racer-X.

If it ain't broke....

I'd leave it. My race bike does not have drilled slides and doens't worry about it.

My road bike used to...but now I've RVF carbs so no need

Only reason I'd do it, if I were you, would be if I had some spare slides

If you want a spare set of carbs to pinch the standard slides I can send them over to you, that way, if you don't like it you can resort back to standard.

£15 + £7.50 postage

It won't alter the fuelling per-se.

However, if you drill the slides too much they'll be able to move faster than the engine is able to react so you might get an over-rich (bog) situation.

Drilling the slides is very similar to fitting weaker carb springs.

Agree with Mark, if it isn't broke dont' fix it.

The throttle response is never going to be like a modern FI bike anyway.

Might be worth tracking down some NC24 sliders, they have 2 smaller air holes and a curved bottom, try them and see how you get on with them.

Neosophist wrote:The throttle response is never going to be like a modern FI bike anyway.

You'll never have an on/off like throttle response.

Might be worth tracking down some NC24 sliders, they have 2 smaller air holes and a curved bottom, try them and see how you get on with them.

I've drilled slides in the past and to be totally honest, haven't noticed a difference. Now I run the curved NC24 slides and, erm also don't notice the difference In both cases though, the carbs have been pretty much fully modded.

Maybe you would notice on a standard carb set-up though? Stick to 2.5 mm and you can't go wrong - and no it doesn't effect fuelling. Hey, it doesn't cost a thing to give it a go