New 650 Supermoto owner with carb question?

good onya taffy , - dale , i am about to disconnect my tps , i dont care about mileage . thanks for advice 8)

Hi Dale,
If you're up to it, another question on the TPS. I understand what your saying about the light throttle/high RPM combination needing more advance due to poor mixture/turbulence in the combustion chamber. Thank goodness for electronics so they didn't put a vaccum advance unit on it like the auto makers did in the 60's. Anyway, with the TPS unhooked will the advance curve be similar to an SEM? If so, to me this is good news that such a simple fix is available to rid the newer bikes of the jerky throttle response and smooth them out a bit like the older models. Young guys that like the snap can ignore this. Also, am assuming also that the TPS is defeated at idle to aid starting. Surely so?
dan

dsducati said:

Hi Dale,
If you're up to it, another question on the TPS. I understand what your saying about the light throttle/high RPM combination needing more advance due to poor mixture/turbulence in the combustion chamber. Thank goodness for electronics so they didn't put a vaccum advance unit on it like the auto makers did in the 60's. Anyway, with the TPS unhooked will the advance curve be similar to an SEM? If so, to me this is good news that such a simple fix is available to rid the newer bikes of the jerky throttle response and smooth them out a bit like the older models. Young guys that like the snap can ignore this. Also, am assuming also that the TPS is defeated at idle to aid starting. Surely so?
dan

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Hi Dan,

Disconnecting the TPS limits advance to that of the rpm based curve. Said curve is far superior to any of the SEM models.

For what it may be worth:
The TPS input is used to trim the rpm based curve and does not provide for a separate map.

Idle advance remains the same providing idle rpm and TPS were originally correct.

Example:
I believe under 2000 rpm and below .5 volts indicates idle to the processor.

In any event unplugging the TPS defaults to the base curve and consequent correct idle advance.

Kind Regards,
Dale

Follow you on trimming the existing RPM based curve which is superior to SEM's. With it unhooked does it smooth the throttle response? Is it correct to assume it doesn't effect things at starting RPM's so unhooking it won't improve the cranking?
dan

dsducati said:

Follow you on trimming the existing RPM based curve which is superior to SEM's. With it unhooked does it smooth the throttle response? Is it correct to assume it doesn't effect things at starting RPM's so unhooking it won't improve the cranking?
dan

Click to expand...

Not unlike the Japanese brands it has been my experience that with proper fuel delivery deactivating the TPS does indeed smooth power delivery, albeit at the expense of fuel economy.

Starting has proven to be the same either way.

Sincerely,
Dale

Taffy, you are a real stand up guy! I am impressed! As a matter of fact, I'm impressed with everyone on this post! I am learning much just listening.

Are these bikes notorious for being hard to tune? Is it a common practice to have them run rough and sputter at certain throttle positions? As I said earlier, I rode another identical bike and it had the same stutter at the same throttle position. The owner had no idea it ran rough. He thought it was great but it's not.

Husaberg is sending a new needle which according to them will lean out the fuel. What is your opinion on leaning the needle with these jets?

Lineaweaver, you seem to have a really good handle on fuel delivery, is there any way of looking at the lettering on the needle such as mine (OBEKR) and figuring out the amount of taper etc. by the letters? I'm sure the letters all have meaning as to the performance of the needle but no one can come up with a chart or explaination as to exactly what they mean?

Any help is appreciated. I just want this little fire bolt to run good!

Steven

TufBusa said:

"The owner had no idea it ran rough. He thought it was great but it's not".

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Hi Steven,

You nailed it with a single statement!
Most every Husaberg feels great compared to a TT 500 or equivalent.

My point being "The best you have ridden is the best you know".
Such a statement equally applies to various states of tune amongst like Husabergs.

EKR = 1 Degree taper, 60.39 mm L1 and 2.755 mm root diameter.

Sincerely,
Dale

Reprint
Needle code:

1st letter indicates taper. Letters toward the beginning of the alphabet are leaner (more gradual taper), letters toward the end of the alphabet are richer (more drastic taper).

2nd letter indicates the L1 measurement. This is the distance from the top adjustment clip to a portion of the needle where the diameter is 2.515 millimeters. Letters toward the beginning of the alphabet are richer (shorter measurement), letters toward the end of the alphabet are leaner (longer measurement).

3rd letter indicates starting dimension or root diameter of needle. Letters toward the beginning of the alphabet are richer (thinner diameter), letters toward the end of the alphabet are leaner (thicker diameter).

35-41mm FCR

A 56.25 72.20 2.605
B 56.70 72.65 2.615
C 57.15 73.10 2.625
D 0d 45" 57.60 73.55 2.635
E 1d 00" 58.05 74.00 2.645
F 1d 15" 58.50 74.45 2.655
G 1d 30" 58.95 74.90 2.665
H 1d 45" 59.40 75.35 2.675
J 2d 00" 59.85 75.80 2.685
K 2d 15" 60.30 76.25 2.695
L 2d 30" 60.76 76.70 2.705
M 2d 45" 61.20 77.15 2.715
N 3d 00" 61.65 77.60 2.725
P 62.10 78.05 2.735
Q 62.55 78.50 2.745
R 63.00 78.95 2.755
S 63.45 79.40 2.765
T 63.90 79.85 2.775
U 64.35 80.30 2.785
V 64.80 80.75 2.795
W 65.25 81.20 2.805
X 65.70 81.65 2.815
Y 66.15 82.10 2.825
Z 66.60 82.55 2.835


Example: An OCEMR needle would have a taper of 1 degree 00", an L1 dimension of 77.15mm, a root diameter of 2.755mm, and be intended for use in the large FCRs.

Needle selection:

1st letter: This portion of the needle controls mixture between approximately 1/3 and full throttle. If the engine fails to respond to main jet changes, you may be too lean on this, causing the tip of the needle to be very large. This would tend to artificially limit fuel flow at full throttle, taking control of WOT fuel delivery away from the main jet. Selecting this is much easier than many believe. If you find that mixture is good at 1/4 throttle, but too rich at 3/4, you probably have a needle with too great a taper angle. If the mixture is good at 1/4 throttle, but too lean at 3/4, you probably have a needle with too small a taper angle. I know you went and made sure the main jets were sorted out before testing the needle taper, right?

2nd letter: This generally doesn't need to be played with much. If, when adjusting the clip, you find that you are at the 1st groove and still need to start the taper later, you may need to select a needle with a longer L1 dimension. If you find yourself at the 7th groove and needing to start the taper earlier, you may need to select a needle with a shorter L1 dimension.

3rd letter: This portion of the needle has the greatest effect on mixture between closed and 1/4 throttle. If the engine is too rich while gradually accelerating through 1/8 throttle, select a needle with a larger root diameter. If the engine is too lean when gradually accelerating through 1/8 throttle, select a needle with a smaller root diameter. You will drive yourself completely batty trying to sort out this if the slow fuel and air jets aren't right. Conversely, you will drive yourself completely batty if you try to sort out the slow fuel and air jets if the needle root diameter isn't right. So you're pretty much screwed either way here. And if you didn't set the float level to 9mm, just go jump off a cliff right now and get it over with because that will have a fairly large effect on how much fuel spurts up through the needle jet when the slide's only open a little bit.

Clip position: This controls mixture between approximately 1/8 to 7/8 throttle. Higher clip position for leaner, lower for richer. Unlike taper, this setting will change mixture (approximately) evenly throughout the throttle position range, with a slight tendency to affect the lesser throttle positions more than greater. You should work to find a needle which allows you to run the clip on the 3rd, 4th (middle), or 5th position. If you find that mixture at 1/3 through 3/4 throttle is too lean, raise the needle!

Re: EKR

Hey, wait a minute, EKR! Where did that come from?

Ah yes, I see, the optional 650 offering from Husaberg.

Taffy was indeed correct! (He must have noted the EKR option, Sly Devil.) I on the other hand chose to assume a DVT to be in place. Indeed, we all know about ass-u-me.

Great job Taffy.

Sincerely,
Dale

RE: Re: EKR

anybody ever hear if Tufbusa ever got the rough running figured out?

DSducati- did disconnecting your TPS smooth you out as you wanted? I am looking to smooth out the power delivery a bit just wondering if it worked. I will be disconnecting mine and seeing what it does- fuel economy be damned, a bigger tank is coming!

TufBusa said:

I tinkered with the mixture control screw, tweeking it little by little each direction but had no real effect on the problem. I put it back to the factory setting.

My dealer is very new to the Husaberg Dealership. They are and have been a major Suzuki Dealership since Columbus found Plymouth Rock and their mechanics know very little about the berg. I may have to take it back and let them figure out what the problem may be?

I'll try letting the oil level drop down to the bottom of the window when cold and see what that does for the oil consumption. I usually add about 3 oz. of oil per tank of fuel. But I have been keeping the oil level up towards the top of the window when cold.

I do spend a considerable amount of time on the rear tire with the front high in the air. I have been a wheelie guy forever and I keep all my bikes oil level above the full mark for

that reason. Could leaving the oil level at the bottom of the window while doing sustained wheelies lead to oil starvation or cavitation?

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You absolutely must remove oil so that only about 10mm is shown or under half the site glass is filled when cold...if you keep filling it to the top of glass, your bike will suck the excess through the breather and burn it out the exhaust until it is at the correct level...you are definately over filling it.

RE: Re: New 650 Supermoto owner with carb question?

1/4!!! Thats A Bit Large. Should Be 1/6 Or 1/8 Of A Turn From Touching Valve Stem.
Think You've Gone Wrong With Regards To Taffy's Instructions.
The Clip Positions Are Counted From The Top,That Being 1 And The Bottom Being 7,Now Dropping The Needle Would Be Going
From C6 To C4,Thats The Same As Raising the Clip.
Think You've Gone The Wrong Way. You Should Be On C2 Or Second From Top.
Does That Make Sence?

RE: Re: New 650 Supermoto owner with carb question?

ALWAYS TALK ABOUT WHAT YOU DO TO THE NEEDLE AND TRY NOT TO SAY FROM CLIP X TO CLIP X.

so, "i raised the needle two clips to c5" is the easiest way to say it.

regards

Taffy