Went for a ride the other day my ktm 450 died couldnt get it too run brought it home checked valve clearances all ok cleaned carburettor out and jets all ok checked spark at plug all ok bike still wont kick start it has electric start the battery is flat static voltage is 11dc volts when try and crank it drops too 2dc volts would the battery have an effect on my bike starting when trying too kick it over cheers mitch

if it is running and not making any noises then I would only consider the piston, rings and liner as a last resort
If it has valves , (4 stroke) , check the valve clearance and adjust to specifications as valve stems get longer when hot and if the clearance is not sufficient when cold then a valve will be held slightly open when hot
next check the coil and ignition module and the timing

Thank you for contacting FixYa with your inquiry.
According to the KTM service manual the cold valve clearances for this model are as follows:
Valve Clearance Cold intake - 0.07....0.13mm (0.0028...0.0051 in) Valve Clearance Cold exhaust - 0.12--- 0.18mm (0.0047...0.0071 in)
If we can provide further information please advise.
Kind regards,
TF

Thank you for contacting FixYa with your inquiry. I have been going over some of the older help requests that have been archived and
trying to provide solutions for those that didn't get answered. Hope
this information helps.

Try these:

KTM Owners Manual

Start here

http://www.carlsalter.com/motorcycle-manuals.asp

http://www.ktmusa.com/download.php?dataID=8101G9_OM_EN.pdf

KTM Service Manual

http://www.ktmcyclehutt.com/ktm-parts/ktm-parts-search.php?ktm-motorcycle-parts=Repair-Manuals&year=2007&ktm-model=sxf-450&fitment=bigbikes-all

KTM Repair Manuals Order Site

http://www.repairmanual.com/KTM.html

http://www.tryvod.com/search/ktm-2008-450-xcf-owners-manual-download.html

http://www.pdf-manual.com/user-guide-instruction-owner-manual-ktm-450-exc-2008-17793.html

http://www.pdf-manual.com/telechargement2.php?id=17793

http://www.mydrive.ch/browse#/

Manuals General:

http://www.dansmc.com/shopmanual2.htm

Other Manuals Sites:

http://www.fixya.com/motorcycles/ktm

Had this very same problem with a KX 85 last week! Turned out funnily enough to be the spark plug. So try this first mate. If that dosn't fix it then you have the age old mechanics question "did I do somthing wrong or is it just a coincidence". Start back at your beginning next & re-check your valves.Most of these late model bikes(12000-16000rpm screamers) have titanium COATED valves. Once the coating wears off they close up valves REALLY QUICKLY!!!!! If the clearances are ok your work was good & at least it will rule out insuficient valve clearance as the cause to your problem.If it still plays up - well then I would use the process of elimination to solve the problem i.e is it electrical,fuel, or mechanical. With valves checked already a compression or leakage test would pritty well rule out the mechanical system.To test electrics on motorcycles without test equiptment & a lotof know how can be difficult & EXTREMELY DANGEROUS( shock hazard 40,000 v+). So I'll try keep it simple. On the web you can purchase ignition spark testers that will connect to any plug lead & cause the ignition system to jump a gap of 6 to 8mm.These are cheap & will test the system as a whole for its performance. Great for a quick check of any ignition system. If the spark seems fine then your left with the fuel system. check for blocked fuel tap,water in tank or carby bowl,blocked fuel filler cap vent,blocked carby vent hoses,accellerator pump function.
I hope this has been somewhat helpfull.
I am happy to help with further questions
Regards Andrew

Runs better with choke means the mixture is lean,
Has the exhaust been changed.?
Did this problem just begin.?
Check for air leaks on intake manifold.
Clean carb.
Check valve clearances
raise the needle jet one notch
one size up in the main jet.

check one item at a time, and write notes about jetting changes.and improvements
I also run Moreys upper cylnder lube, helps starting hot or cold, and helps stop "cough stopping" with heavy rear brake use

I'd start with simple things like checking the plug and doing a few electrical tests.Some tests you may be able to do yourself like resistance checks.Compare the following spec with what you get ; Primary coil . 25~35 0hms Secondary 5050~7550 Valve clearance inlet 0.10~0.15 exuast 0.15~0.20 both cold and in mm.

check inlet valve clearances. they close up making it hard to start exactly as you described. titanium valve coatings wear and ressesion happens quickly,a clean air filter must be maintained to prevent contaniments wearing valve coatings.

Pull the slide and move the jet needle clip down 1 or 2 notches.

yes, you are correct, those are the two pieces that could solve your problem, but i would go first for your cdi, you may choose to have it tested first also, before you jump out to buy a new one.

I don't think this is a float issue. One way to check is to turn the gas off, take the bowl off the carb, hold the float up, and turn the gas back in. If fuel flows, the float needle is toast. It sounds suspiciosly like a worn topend, but it could also be a clogged jet ot fuel filter, or a faulty CDI.