ktm 540 2 stroke jetting help!!!!!!

[wesley]

Hey ya all, my ktm 540 DXC 2 stroker has just arrived and im having trouble with it running rough....it will not rev out just splutters,,it wont rev out even with the bike in neutral, i have pulled the delorto carb off and pulled it to pieces finding it very clean....has a 180 main and a 45 pilot with the clip on the very top notch.....i cannot see anything wrong....the bike came from melbourne....im in cairns and at sea level.....i cannot find any jetting specs for this bike....and i have no experiance with the delorto carb.....can someone shed some light!!!!!!!!!!!

[paul]

hey wes should of ask me to look at it before you bought it  it was only round the corner 

[Lozza]

Wes del'orto's a great carbs just people don't have lot of experience with them.Jet sizes are a the hole size not flow like Mikuni's so your 180 should be a 1.80mm hole.If there is a VW tuner in your area they may have the Del'orto jet drill kit which you can solder up the jet then drill then test until you get the right jet.Kart shops that have jets for the Rotax Max engine should have plenty around the 170-150 size.Also you should be able to find an engineering place that has a huge range of drills so you can check the 180=1.80mm bit and truth be known a drill will be about $3 to buy.
With the running it definitely sounds rich, but as always check the plug.The only thing that affects jetting dramatically is temperature.But you will have to jet it for Carins anyway.
My dubious advice would be to seek a 1.75mm drill solder up the main and see if that is better, if yes the solder up again and drill with a 1.70mm drill etc etc until it will rev and have some colour on the plug.Should be able to do the same with the pilot.As for needles the Kawasaki plce here does get them in but you should be able to google up a supplier.
HTH

[wesley]

Paul.....hey Paul yeah i no but its only a tuning issue i will work it out in time the bike is immaculate.        Lozza.......thanks for your help and advice,,i will start soldering and testing so you think i should reduce the jet size first?....it has 2 pilot jets ,well i think one of them must be a starting circuit i would think,should i lift the needle a notch ? but that would be richening it up though...

[Nathan S]

It's not just a dodgy needle and seat? They're shit in Dellortos.

My TM had all the signs of a dud N&S (running super rich, running clean briefly when the fuel tap was turned off, etc) except it didn't dribble fuel out of the float bowl, so I kept looking elsewhere.

Replaced the N&S and problem fixed.

[YSS]

Just check your cut away too , Dellorto has 60/1   60/2   60/3  and so on.
They are great carby with so many adjustments. ( Maybe too many )
There are also many  needle seat sizes , needles  etc.  I only run Dellortos 36 PHFon all my classic bikes.
When I hade the 540 KTM in 86+87 they where fitted with Bing carbies.
I still have a complet Dellorto Part book  if you need part numbers .
regards Walter

[Hoony]

Yes i too rode a 540KTM in 86 and it had a Bing (complete with old school fuel tickler)

maybe the delorto was fitted later has never been set up correctly ?

[Moto]

 Just a thought,
                    As you dont know too much about the condition of your new toy. I would check the main bearings at the ignition flywheel for play,they had a bad habit of failing ,causes the ignition to do funny things.

[wesley]

Hey all thankyou for ya help and advice....i have spent all day on it and it still runs the same ,i am about to set fire to it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!...its a little spluttery down low ,then cleans its throat in the midrange and thats it no top end charge at all ,,,,just spluttering!!!!and clouds of blew smoke,i am running motul 800 ester at 40:1 , i have been over everything twice,the engine has huge compression,im 6"5 and nearly 100kgs and i takes a healthy boot to spin her over...
pull the plug out and its just oil!!!! so its rich as hell,,,,blows lots and lots of blew smoke hot or cold....it runs like a cold 2 stroke, but all the time.....i rang my local ktm dealer today to get some info and was told that they never made a ktm 540dxc 2 stroke ,so thats the sort of dealership that im dealing with!!!!

[Hoony]

it may have a possible leaky gearbox side crankseal causing it to suck in gearbox oil !

[wesley]

Hoony.....that crossed my mind today also......but its not blowing enough smoke for me to replace it.

does anyone know where i can buy a new ignition system for this bike,the one thats on it is a( sem k11 )(made in sweden) written on it..

[paul]

hey wes you worked it out yet 

[wesley]

ok i turned off the fuel started the bike and waited to see what would happen ,and yep as she started to run out of fuel she revvvvvvvvvvvvvvvvvvvved to the moon so nice and clean i couldnt turn it off!!!

[Lozza]

Wes,
I just thought you could go to a Dick Smith or JayCar electronics store and pick up a set of small drills(usually in the 0.35-1.3mm) range with a pin vice Should be $15 bucks or so.I was fairly sure it is a straight jetting issue.
Has the carb got an air screw?You could try truning that out to see if the idle circuit fueling improves?

[wesley]

Lozza ....yes it has a air screw,,,,i did a little more looking and have found the needle to be bent.....would a bent needle and a worn emulsion tube be the problem of my rich running??