popping back on shutdown

jonnieboy · Jan 29, 2005

hi guys
just been scanning some old posts on this subject and would like a few ideas please
bike is 02 650 with dellorto carb
pops back a lot, noticed it a lot on motard trackday was a pretty cold day 10 c max .marshalls were complaining about noise
ive stripped carb down and this is settings

needle pos top groove

mixture screw 1 1/4 out

main jet 190

pilot jet 30 :?:

bike starts ok on button or kick couple of turns over with choke on drop choke off and it will go

pilot seems small so is the way to go up with that ? if so how far at a time
why is the needle right down ?
has anyone had a car gas analiser on their bike any ideas as to what sort of % co2 (if thats what it is )that it should be ?
plug always looks ok and the dealer i got it off reckoned they had to go so lean on the pilot to get it to run properly from new (i dont really believe them as the bike was bad to start on the button when i got it and they said they'd done everything they could and when i shut the tappits up to the right setting its been fine since )

cheers
jon

44014 · Jan 29, 2005

hey jonnieboy

have you looked at your exhaust make sure you get a bit of goo around the head and where it joins half way along may go along way to reducing the popping when you back off .But on that nore it is completely normal for a big high performance 4st to pop on decel

cheers doug

madero · Jan 30, 2005

Seems that your carb set up is too lean for that cold temperature.
I have seen popping on the bench from 14 on 1 Air-fuel scale,with FP and Doma config.

Taffy · Jan 30, 2005

johnnie boy

i feel you should be developing the bike yourself anyway. try a 33 and then a 35. if it's running lean you'll notice an improvement with the larger PJ's.

i woulkd try lifting the needle. it's on it's leanest setting. if lifting the needle doesn't work-go to a 200MJ.

regards

Taffy

Simon · Jan 30, 2005

As Taffy says, go to a 33 or 35 pj and lift the needle - the clip say to 3rd from top.

190 main should be fine although some of the 01s did benefit from a 200 main with some exhaust systems - about the 185 with a stock road/enduro pipe.

What needle, needle jet combo are you using?

Simon

jonnieboy · Jan 30, 2005

cheers for the starters
will get some jets and have a go

needle is k51 and dr 272 jet

feel an itchy head coming on
thanks again
jon

FinMoto · Jan 31, 2005

ciao ,

mine is doing the same, stock 02 FS650 with open pipe,
will report the jets later, glad to hear the advices.

FinMoto

Simon · Jan 31, 2005

jonnieboy said:
needle is k51 and dr 272 jet

Those should be fine.

Simon

Supermoto_Husaberg · Jan 31, 2005

I have this problem too 02 650, Mikuni carb and FP exhaust.

Need to seal the exhaust sections together and then fiddle with the jetting.

Lloyd

jonnieboy · Jan 31, 2005

might be going to cheat a bit !!! :wink:
rang a mate today who has a dyno to see if he had any jets and for 30 pounds well run it up on the rollers and see the fuelling all the way through
i know its not really cricket but when messing with jap multis i always got good info so should be interesting

what sort of limit do bergs rev up to ?and what are we looking for hp wise ?
will try and post charts up wont be for a week or two due to imminent baby arrival ie when im allowed to play again
jon

JoeUSA · Jan 31, 2005

Jon,

Check out the charts on Dale Lineaweavers Gallery here:

http://www.husaberg.org/modules.php?set ... php&page=4

Joe

Supermoto_Husaberg · Feb 1, 2005

With a standard exhaust your looking at around 48rwhp.

With a pumper carb and a race exhaust then maybe 54-56rwhp.

Lloyd

jonnieboy · Feb 16, 2005

well, got to play on dyno today
ran it up first with jetting as above
it was running lean and very lumpy ,so i lifted needle 1 groove - it wouldnt start so hopped into van 30 mile dash for jets when i got back i put needle down again and it fired up ok so we put 33 pilot in and ran it up sounded sweet only occasional popping on shut down but it ironed out the curve pretty well so

I'M IMPRESSED !!!
(if it starts tomorrow)

will try to add dyno sheet to somewhere

jonnieboy · Feb 16, 2005

chart is in gallery now
the only difference between the 2 runs was 30 to 33 pilot jet

Supermoto_Husaberg · Feb 17, 2005

Jonnieboy,

What spec is your bike (pipe, carb etc) I looked at the dyno result in the gallery?

Lloyd

Parsko · Feb 17, 2005

That is a serious difference for only changing one jet!!!!

You'll definately feel that on the trail/road.

I bet you're happy you did that!

-Parsko

jonnieboy · Feb 17, 2005

Lloyd

bike is 02 650
standard pipe and carb is dellorto 40 with jetting as above dont think its been touched internally, cdi/coil is 03 item

parkso

yep as long as i dont loose its good starting ill be well happy just need some drier warmer weather or a decent pair of wets and ill be out
i think he used the worst run for comparison but even he was surprised how much change the pilot made right through the revs

Supermoto_Husaberg · Feb 18, 2005

I only got 48 hp on the standard bike, that 03 CDI must make quite a difference. OR maybe its the fact that u got yours dyno'ed in colder weather ?

The best thing I did to my 02 was to fit a pumper carb which gives u loads of mid range get up and go.

Lloyd

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popping back on shutdown

jonnieboy

44014

madero

Taffy

Simon

jonnieboy

FinMoto

Simon

Supermoto_Husaberg

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JoeUSA

Supermoto_Husaberg

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jonnieboy

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