00 610sm jetting help wanted

I have a 00 610sm e start. I put two straight through tailpipes on it and trying to get the jetting right to suit. There is a surge/stutter when trying to hold a steady speed on low throttle and getting some loud popping on decel. I have changed the main jet to 185 which has helped a little with the popping. The carb is a dellorto and is currently running
Jet sizes:
Main= 180 changed to 185
Idle = 50
Start= 50
Atomiser= ab 260
Venturi valve= 300
Needle= k32
Fuel screw=2 turns out

Any advice will be much appreciated, thanks.

Oh also if I open the throttle really quickly it seems to choke the engine.

Popping on decel, is not a jetting issue you've derestricted the exh, raw fuel is touched off by air leak getting into exh thru slip connects.
You need to get a flex jet so you can adj the air fuel mixture, with out it to difficult to make this adjustment.
Your jetting #'s are in the ball park with exception of idle jet (60-65) fuel mixture adjusts the flow of this jet as in fine tune.
The Flex jet is the fuel mixture screw with a flexcable attached to it so you can turn it.
Later George

I have all the joints sealed with exhaust paste. The popping does get less and less the more i turn out the mix screw. does the flex jet replace the mix screw? So u recomend changing the idle jet to between 60 and 65? Thanks for your help George.

It's a dellorto phm 40 carb. If that helps.

Yes it is the same needle just with a flex shaft with a knob on the end.
There are a lot of aftermarket extended screw on the market but still have to put your hand and fingers in a tight hot environment (burns the crap out of you) then you just say screw it that's close enough.
By turning it out you are letting in more fuel.
Go with a flex jet makes tuning much easier and once you get familier with it you can do it on the fly.
Later George

Cool have you a link to one? Thanks again George.

Sorry had major Brain Fart you don't need Flex Jet your fuel screw is just in front of Idle speed screw.
Bike hot very low idle turn in clockwise until it wants to start to stall (to lean), then turn counterclockwise until it wants to start to stall(to rich) then set it in the middle of these two points.
Then set idle speed to your liking .
If it starts to rev when going in on fuel screw back out idle speed to low idle and continue.
Later George

Thanks George more or less have done what you said there. Running better now though doesn't like colder mornings and still a slight miss when holding a steady speed around 1/4 throttle.

Now that you say that it is around the 3000 mark. Nearly sure I have one of hose plugs in it.

That's exactly when it's doing it. Just a wee miss every so often. What's different about the 03/04 box?

Cheers. Thanks again.

jetting as above and 62 idle jet the bike has a hard time hot starting...the only way it will start is closed throttle and just cranking it.....anybody has any ideas?

Check your slide to carb body clearances, either could be worn out.
If it runs good at wfo just ride it there.
Later George

Slide and body look good, and yea George, that's what I have been doing

But it would be nice to make it hot start easily, as sometimes it just takes took long

An update on this .... I gave up on the Dellorto because of the difficult hot start and got an FCR41MX from the 2006 Husqvarna TE610. The bike starts, runs, and pulls much better, it is almost perfect. However there is still this little bit of a "surge/stutter when trying to hold a steady speed on low throttle". I am running the ever popular OCEMN needle and the NGK C7E spark plug.
I am very happy overall wit the swap.

NOTE: I had use the heat gun to shape the inside of the gas tank around the right/cable side of the carb for clearance.

Many years later and I still love the FCR41MX. the bike now starts easy hot or cold!