Needle/Main Jet relationship = Slightly confused

[GGRider01]

Currently the bike is running better than ever but clip position testing, out of curiosity, has me confused.

Current arrangement:

42P
NEDH, #2
172

I thought I'd try and go one step richer on the needle, since I started in #2 when I put it in. It became a sputtery mess in #3. With other setups, changing needle clip position only seemed to change half throttle behaviour, and very little in the way of noticeable full throttle behaviour.

#3 position would not allow the bike to rev out even after a lot of running around. It was just doggish past half throttle and sputtered endlessly.

I can easily throw jets in and test for myself, but at this point I don't think I know what I'm doing exactly. Would the needle position testing suggest a leaner main jet? Or something else? Interesting note: I can go up to a 175 and even a 178 with no sputtering but less over rev, but a clip change throws everything out of whack so drastically.

[Jakobi]

That depends on what you've changed to or from.

The relationship is that the main jet flows fuel into the nozzle. The needle interfaces with the nozzle and restricts the amount of fuel that can flow past at a given throttle position.

A full clip position is a pretty crude/significant change in fuelling compared to a main or pilot change.

Add to that, different needles series can have different taper profiles.. they provide different amounts of fuel at different throttle positions compared to other needles of different series. The Suzuki NE needles provide a lot of fuel through the mid, and even more towards WOT. Especially compared to a Yamaha/KTM N3xx series.

It's likely the case that you are simply seeing too much fuel through the mid and it's not allowing it to clear into the top end.

[swazi_matt]

Originally Posted by Jakobi

That depends on what you've changed to or from.

The relationship is that the main jet flows fuel into the nozzle. The needle interfaces with the nozzle and restricts the amount of fuel that can flow past at a given throttle position.

A full clip position is a pretty crude/significant change in fuelling compared to a main or pilot change.

Add to that, different needles series can have different taper profiles.. they provide different amounts of fuel at different throttle positions compared to other needles of different series. The Suzuki NE needles provide a lot of fuel through the mid, and even more towards WOT. Especially compared to a Yamaha/KTM N3xx series.

It's likely the case that you are simply seeing too much fuel through the mid and it's not allowing it to clear into the top end.

So if you have a rich mid the best (only?) change is to go leaner needle type?

[GGRider01]

If anything, I feel the mid throttle is a tad lean. For instance, if the bike is cold, it will rev nicely at half throttle but sputter on full throttle. Once it's warm, of course full open performs as expected, nice and clean.

I'm wondering how to richen the mid without getting a blubbery mess on full throttle that a clip position causes.

As it stands, the bike is very much acceptable. I'm just trying to get a further grasp on what's what so I started moving things around. It would be nice to liven up the mid section without hindering top end.

[Jacob 'Berg]

Originally Posted by GGRider01

If anything, I feel the mid throttle is a tad lean. For instance, if the bike is cold, it will rev nicely at half throttle but sputter on full throttle. Once it's warm, of course full open performs as expected, nice and clean.

I'm wondering how to richen the mid without getting a blubbery mess on full throttle that a clip position causes.

As it stands, the bike is very much acceptable. I'm just trying to get a further grasp on what's what so I started moving things around. It would be nice to liven up the mid section without hindering top end.

If that is the case, maybe a different taper and/or diameter needle, which would clear up the transition onto the main jet.

[barossi73]

Nech is halfclip leaner than nedh.
I also found nedh#3 too rich/sputtery and nedh#2 a little flat.
Nech#3 is right inbetween and works very nice on my 200.very occasionally (once) sputters when it gets a little hotter than usual.concentrate on how it runs fully warm.if it runs good cold it will likely splutter and choke when it gets to normal temp

[barossi73]

Is the 'h' the same diameter as your stock noz? or n1e?
the 'w' and 'j' diameters are typically 250/300(i dont recall which is which!)

[Jakobi]

Originally Posted by barossi73

Nech is halfclip leaner than nedh.
I also found nedh#3 too rich/sputtery and nedh#2 a little flat.
Nech#3 is right inbetween and works very nice on my 200.very occasionally (once) sputters when it gets a little hotter than usual.concentrate on how it runs fully warm.if it runs good cold it will likely splutter and choke when it gets to normal temp

This. Half clip adjustment.

The main will have some influence across the board as it regulates the supply to the nozzle.. but this will have a more pronounced effect as the needle taper allows more fuel between the needle and nozzle.

[GGRider01]

My methods have certainly changed since I first set out. The first thing I look for after a change is that the bike sputters when cold since it will clear up once hot. Wide open is, I suspect quite close if not still a tad rich, overrev isn't great. 175 on the main made it slow to hit 80. 172 is quite good.

Half throttle is concerning since it's strong cold and a bit flat once hot. A little lean.

Needle diameter affects which portion of the throttle opening? It might be interesting to try the G diameter again to get a nice fat mid but I'm afraid I'll have to go very lean on the main to clean up wide open position.

Only one way to find out but thoughts are appreciated. NECH on order.

[GGRider01]

Originally Posted by barossi73

Is the 'h' the same diameter as your stock noz? or n1e?
the 'w' and 'j' diameters are typically 250/300(i dont recall which is which!)

No idea. Stock was a N1ED and it was all around pretty awful gutless spooge machine.

Testing the NEDH in #1 position revealed a dramatic improvement throughout, half throttle still isn't what I'd like. Zipped around town and it never felt flat, just a bit at mid. Testing might indicate a size down on the main, NECH will definitely be an improvement and not require the size down on the main to keep it away from the #1 position like the NEDH.