A funny side story, a few months ago my bike stopped idling and i found out the mix screw had come out. So I put a piece of dryer vent tape over the hole and it ran pretty decent until the end of the season.

The bike really needed lots of work. I did the fork seals, changed both tires and tubes, bled both brakes, did the venting and smog mods, cleaned and oiled the throttle cables, cleaned air filter, going to true the rear rim, changing out the stock headlight for a bright led, redid the carb, cleaned the chain in kerosene, new front sprocket.. All fairly cheap things just time consuming. I'm hoping it'll be like a new bike come spring

 

Hey klxster.. I took the bike for a spin tonight. Def runs better and beefier. I wanted to ask why you suggested to put the needle at the 2nd position rather than the third? Wouldn't the third position give more power for lower throttle? I feel it's lacking a bit. Wide open is nice, although I can't get it up like yours without popping the clutch

 

Ok, I assume you are now running 140/2N lidless ?

On my video, you can see exactly the speeds I ran before snapping to WOT and raising the front tire. If you can't duplicate that, don't worry.. I am running the MCM, which "ramps" up torque more aggressively in the mid-range ( as well as producing more "total" torque in the mid-range)... I expect your bike (with its' stock cam timing) to produce a healthy torque ramp-up from a starting point higher up in the RPM range than mine - exactly how much higher up or at what starting point, I can't say.. Reread post #16..

As expected,(post #19) the upper-mid to top-end power is now so enhanced that the low to mid range could feel weak.. However, you can change the characteristics of your throttle response and power "ramping" below 6.5k with the needle clip position.

Do you want me to just tell you what to do and what to expect or do you want to also understand the effects on fueling that a clip change produces?

 

I just notice it feels weaker than it did before in the low throttle range. What will changing the needle to third clip position do other than richen the low to mid range?

Will change the spark plugs and do that test to be sure though. Keep in mind I have an 06. A buddy has a later model and it is faster and more aggressive, stock.

On another note, it feels so smooth compared to before and sounds so beefy. Probably because of the smog and air box mods

 

Yes, 140 main, needle second position, lidless. Everything is improved except for the lower to mid throttle feels weak. Weaker than before, not just weaker than wide open. But so much smoother and proper, definitely

 

The new "beefy" sounds and "smoothness" is all due to 140/2N lidless with a slipon near or at sea level - it is a product of proper "performance" fueling. All the transitions - pilot system fueling to needle fueling, needle fueling to main jet only fueling are all optimized and AFR across the entire operating range is now perfect (or near perfect, see below).

Now, about your "low to mid" power and throttle response:

Overfueling with the needle clip position will lessen your TRQ production and throttle response below 6.5-7k even though the bike will still sound "mean" and "beefy" down there.. Your fuel mileage will also suffer --- so lets' not do that, ok?

Note: Since your performance is "smooth" everywhere and all the time, your float level and fuel screw settings are likely optimal. Also, from my Dyno testing/charts, 2N could only be "less-than-optimal" on your bike (creating a weaker midrange) by running the low to mid slightly too rich. Something it doesn't do on my bike due to my MCM. The needle is simply a variable valve for that DJ140 main jet, which will now happily overfuel your midrange with that 228 needle..

I would have you create a test route that focuses on the performance your getting between 4k and 7k. This will allow you to quickly assess changes in the low to mid range power and throttle response.

Your best chance of only having to change your clip position once - and getting the results you want - is to reset to 1N. This means super-gluing or otherwise attaching the two washers on top of the clip.

If you want to try a lesser change first, put the clip on 1N with one washer below and one above - for 1.5N. This is a small change in the fueling curve for the midrange. If this makes a noticeable improvement, you can then try 1N..

If playing with the clip is something you enjoy, then certainly try a ride on 3N too.. just know that 3N would slightly overfuel my bike's midrange... So I would expect your bike to suffer more loss of midrange TRQ than it suffers now..

 

Really, this a all about how your bike feels to you - If it turns out that 3N feels best, RUN IT !

I was certain my bike ran best when I was trying out a DJ150 main jet - the dyno test/chart with that setup proved me wrong.. And the loss of power/trq was shown on the chart, below 6.5k, due to overfueling the midrange.. If I didn't have a dyno available to me for testing, I'd still be running that DJ150 setup and I'd be happy as a clam with it !

 

Perhaps I have not answered all your questions completely. Unlike all those running DJ128's, DJ132's, etc.. your setup now fuels the top end correctly, and more importantly, fuels it correctly with the airbox lid off.. This also means you cannot use "normal" thinking on use of the needle clip positions. The needles' shape produces a fueling curve. The spring/lift hole controls how quickly this fueling curve is put into effect from a given throttle input. The clip positions fine tune this fueling curve by slightly changing the RPM "window" that this fueling curve operates within. The needle only meters the flow of fuel(air/fuel actually) from the main jet - get the main jet right first, then set up the needles' fueling curve to get best throttle response and power in the RPM range that it controls - about 3.5k to about 6.5k.

So, with a main jet that is too lean, you can still get a good midrange by putting the clip way on down on the needle - say 4N or even 5N (bottom most notch) - as this will move the curve lowest in the RPM range - or you could say it "uncovers" the main jet sooner.. Even a DJ132 could fuel your midrange well if the needle is set to 5N..
Get it?

Your situation is exactly opposite to those running DJ128's DJ132's etc .. Higher clip settings are needed in order to keep the DJ140 from overfueling the midrange - allowing all the power and throttle response that your bike can make in this "needle controlled" midrange... Above 6.5-7k @ WOT, the needle is no longer fueling your bike, only the main jet is.. regardless of clip position..

 

I just took it out for a road ride, I got up to 120 km/h quicker than ever and it still felt like it had lots to give. I'm pretty happy with how it's performing, I'll probably leave it. I'm sure it'll do its thing on difficult terrain and hill climbs.

Only thing that's a bit off is the idle.. seems to jump around a bit. I was wondering how you adjust that air fuel screw while the carb is on the bike? I dont have that kouba t-handle attachment, looks impossible to reach. Maybe I can cut the end off a slot screw driver and use that or something.

Thanks a lot for all the advice, it's really performing many times better than before. The video where you do the wheelie.. do you have stock sprockets? Like 14tooth on the front and whatever the stock is on the back?

 

Ok... when I get a little more time I will post a copy of my adjustment tool for the fuel screw. And I am running stock sprockets..