SURGING WHEN SLOWING DOWN

[Waterbuffalo]

To add to Baz original comment, heres somethings I noticed with the surging that are totally related to the carbs.

1 It can effect some bikes more than others and so for those times you need to think outside of the box on those carbs.
2 Altitude also plays a factor with it as well so if you are upwards of three thousand feet above sea level, sometimes you need to make other minor adjustments outside of the stock settings.
For example, most bikes like the 0.8 air jet, but they also make an 0.9 and a 0.7 if you are having issues with the sizing thats not working best for your particular machine.
Since the BS carbs have a long and tortuous route for the mixture circuit, you can also adjust the float height to be a bit higher than stock as well. What this does is to increase the height and available static pressure within the vertical pickup orifice of the float bowl.
I know this all works as I've done a fair bit of testing on these annoying BS carbs and have gotten all of my surging issues solved.
If you have a few bikes in your stable you should also invest in an ultrasonic cleaner, you would be surprised at what gets suddenly loosened after a good cleaning.

[demoderbydave]

CAUSES OF SURGING IN ORDER OF PROBABILITY

Blocked pilot air jet 1mm jet pressed in rear of carb

Blocked main air jet .5mm pressed into rear of carb

Pilot screw wrong should be ¾ or 1 turn out may work better (1/4 turn for L model)

Foam missing in air box fitted in the factory and disappears after powder coat causing lean mixture

Air leak carb to engine also causes intermittent high tick over

Carb butterflies badly out of sync see here http://www.youtube.com/watch?v=Ri8SzrxSHzA

Float height wrong

Throttle cable badly routed/ no return cable http://youtu.be/H4w3Pp5gqMM

Cylinder compression low or uneven

Idle speed set over 1250 RPM

Engine overheating

Air leak - air box to carb

part of piston skirt damaged or missing

End of Butterfly shaft loose

Please note fitting electronic ignition wont cure it! or anything else! .

I followed your dvd and watched it NUMEROUS times, so many in fact that I want the woman who did the narration phone number!
But there is no mention of adding a jet to combat the condition. (Epecially surprising is that was supposedly a suzuki tech bulliten fix)
Assuming you can simply screw that jet in front of the pilot jet I'll give it a try...

[BATTS]

Copy of tech bulletin here. I also, following Mike's example, on my A changed the pilot jets. It still surges but not quite as badly.

http://www.suzukigtriders.co.uk/technic ... 20INFO.pdf

[demoderbydave]

Thanks Chris...

[apwrigs]

There's been some clever stuff going on here, and i think it's fair to say the surging is a carb issue.
I think i can live with the niggle a little longer and then i think ill do the honest thing.

SEND THEM TO BAZ!!

[Alan H]

550s don't surge at all.
CV carbs are the issue, so chuck 'em and get some nice flat slides!

[PaulD738]

550s don't surge at all.
CV carbs are the issue, so chuck 'em and get some nice flat slides!

Neither do the 750J's they are fitted with lovely Mikuni VM's

[swarrans]

I followed your dvd and watched it NUMEROUS times, so many in fact that I want the woman who did the narration phone number!
But there is no mention of adding a jet to combat the condition. (Epecially surprising is that was supposedly a suzuki tech bulliten fix)
Assuming you can simply screw that jet in front of the pilot jet I'll give it a try...

That is very strange because the copy of Baz's DVD that I have got shows fitting the anti surge jets! Maybe you are being mesmerised by the voice over? There's a bit more to it than just screwing a jet in - you have to measure the depth and then tap a thread before screwing in the jet - all shown in Baz's DVD (well my copy anyway!))

Simon

[demoderbydave]

Simon,

I will have to rewatch the dvd and see if i did indeed miss it. But you are correct, i am in love with the narrator!

But I STILL CAN'T believe that Suzuki could have sold them like this and really didn't do much about it... I want a refund!

[yeadon_m]

Baz does do a lovely falsetto
You can hardly hear any Brum, can you?
Mike