Still familiarising myself with the bike, can anyone tell me what the black cylinder is? It was in the workshop getting some stuff done and I'm assuring they forgot to put it back correctly. It's just hanging there not mounted to anything. Scanned through the manual but haven't identified it yet.

UPDATE: identified it - capacitor for ignition coil. And looking at photos online, it shouldn't be anywhere near there

Attachment 16083

Yes that is a capaciter.. It is supposed to mount on the outside end of the tank mount rubbers on the right side just behind the radiator above the spark plug..

I'm curious how that capacitor fits into the elec. ignition system and what role it plays.

Normally wouldn't the CDI unit do that job? I don't recall that unit being on either of my 640's ... but I did not know them very well. ('99 and '01) Both would kick start nicely on a low battery. (Duke ll and Dual Sport)

I'm wondering if that KTM will run with the battery dead like many Japanese dual sport bikes will? Perhaps that is the reason for a capacitor the size of a Beer can ... so it will kick start with a dead battery?

Any ideas? In the old days, capacitors like that would fry (from over heating) and leave you stranded. How's the reliability of that unit? Is the engine dependent on it to run?

Actually it is about the size of a D cell battery...

I believe the Capacitor was added when they 640 moved to the Kokosan ignition... I believe it was a measure put in place so the bike could be started with a dead battery.. I know from experience that they will kickstart with a dead battery but are a bugger... A lot of guys install a shutoff switch on the headlight and say that makes it easier as the light is then not stealing from the spark...

As for reliability I haven't even thought about it, going problem free for over 208,000 km it is a forgotten item on my bike..

A capacitor is used like a battery. It stores energy until it reaches it's peak.

They're often used to smooth out voltages for lighting on an AC only bike like XR650R for example.

Does the 640 use a CDI ignition ?


I guess like said, it's probably used to give the coil enough voltage to create a strong spark when using a kickstart.

But I dont know KTM's... I'm just guessing.

I don't know KTMs yet either..but becoming increasingly familiar..

My (new) battery died the other week while I was trying to start it using the button. Mine still needs a top end overhaul so suspect the auto-decompression isn't working as I have to use the decompression lever to get it started. But I didn't know that at the time..hence the goosed battery.

But I recall pulling in the decompression lever as the battery was dying (and not the starter button) and oddly it was trying to turn itself over.. like the charge was coming from a capacitor maybe?

Anyhow, I tried the kick (am used to doing this on my XR600R) but it just wouldn't do anything. Even pushed it up the hill and tried bumping (lot's of fun in Malaysia..), all to no avail. So I ended up using jump leads and then a battery charger.

So now, I use the starter button and pull in the decomp lever for a second and starts easily enough. I'll need to try kick starting it again now the battery has some charge but it's a still wonder why it didn't start with the kick with a dead battery (unless my technique was off), any ideas?

Kick starting a 640 is all technique!
This is my technique from 8 years of having a 640 Adventure.
This technique requires practice when you do not have to use the bike, so you do not shortcut and wonder why the bike will not start!

• Wear suitable boots as the high compression (12:1) engine will make short work of your leg/ankle/shin if it kicks back – don’t ask me how I know this – it was painful!
• Turn on fuel tap/ignition and any choke if required – under no circumstances have the throttle open.
• Get the piston over Top Dead Centre (TDC) by using the kickstart - slowly with the decompressor lever pulled in.
• Be very careful not to take it too far past TDC.
• Let go of the decompressor lever.
• Return the kickstart to the top of it stroke approximately 3 clicks back on the ratchet.
• Only then have a committed stab at a long, strong and full length swing on the kickstart.
  Important:
  If not successful go back to number 3 and start again.
  Missing out on number 6 will not start the bike as you do not get enough momentum to get past the next TDC and you will wonder how do you ever start this beast!
  
  This method has served me well. I have a friend with a Duke 2 and he could not start his bike at all on the kickstart, he was getting so frustrated/tired/swearing etc.
  Once shown the calm methodical method above he was sorted every time.
  
  Starting the bike after being on its side/upside down/flooded:

• Turn off fuel tap
• Pull in decompressor lever.
• Hold throttle open fully.
• Kick over engine 10 to 15 times – do not shortcut this to say 4 or 5 times as you will not have removed all the flooding and you will never start the thing!
• Only then go to item 2 of the top method above and continue as normal and it will be fine.

PS:
When – not if, you do get the bike up and running any starting/idling problems may be down to the idle fuel mixture screw being incorrectly adjusted.
Easy to do.
Top tip buy a longer adjustment screw to make easier (Demon Tweeks or similar) and then drill/lockwire it to the tickover adjustment screw when done so its secure and the screw does not drop out (no idle at all them) and is relatively easy to adjust if required.
Lots about this adjustment on Avrider/youtube.
Do not be put off, these are good bikes that once set up and maintained properly are brilliant, possibly just you getting to know it and/or previous owner care/abuse issues.

Thanks man, however that's almost the exact same procedure I was using for my XR which I had down to a tee, I could even start it wearing my sandals (not recommended..) :)

Any reason it won't start off the button alone? (although it does very rarely, on occasion start with just the button without the decompression lever, guess it depends where the piston is). I'm putting it down to the auto-decompression not doing it's job which presumably can be rectified during the top end overhaul.

The procedure KTMAndy describes is one I've used for over 20 years of kick start bikes. (2 KTM 640's, numerous dirt bikes, 4 XL, XR Hondas)

Most riders fail because they can't resist opening the throttle when kicking or cranking on starter. The Fuel Screw thing is VERY important. Once set correctly and with a slightly HIGH idle for starting, the KTM should start more easily.

If still having starting trouble even with a FRESH, STRONG battery, then it may well be a compression problem (top end), either worn valves or rings ... or other? (Ignition, pick up coil, stator?)

A few simple tests (leak down, compression tests) can determine if valves are holding pressure or leaking, same with rings ... IF these tests are done correctly. :thumbup1:

(TIP: Don't get suckered into a rebuild you don't need by some dodging mechanic tossing up false flags .. doh)

Good luck! bier

Usually the 640 is one of the easier to kick start thumpers... If you are used to kicking an XR to life the same procedure will apply to the 640 and it should light up easy for you... I just fixed a friends 640 that was having a hard to start issue.. The bike has nearly 70,000 KM on it and after going over it I discovered that the fuel pump had worn a small hole through the diaphragm and a bit of raw fuel was making it through, bypassing the carb, going directly into the intake tract... This caused an overly rich condition at sub 1/4 throttle causing minor flooding at start up.. I rebuilt the fuel pump and now the engine starts up with a quick stab on the start button...

Other starting problems I have come across working on these bikes have been caused by a worn auto decom locator pin, the cure is to replace the cam and in some cases you may be able to file the pin where it has worn round back to a square edge... A slipping starter sprague clutch will also cause issues as to where the E-start slippage does not turn the engine fast enough to generate a good spark... A poor battery will also do it as to where there is not enough cranking boost to spin the engine fast enough for a good spark..

Make sure the ground strap from the battery to the frame lug has good contact...

My KTM Duke ll was the easiest kick start bike I've owned. Wonderful! A delight compared all my XL's and XR's. bier

But the main shaft sprocket nut never came off on the Hondas like the KTM! :help smilie: (at 90 mph!) (left hand thread nut left loose at factory? or :innocent:

Well I gave up on the official KTM guy who basically wasted my time and I suspect he had no idea what he was doing. I took it to a trusted mechanic friend who confirmed that the valves were a mile out, a bolt missing from the head and a bit of an oil leak, the radiator bone dry etc, all basic stuff that the KTM workshop should have raised and rectified.

Anyway, got it back last night and it's starting off the button every single time now :)

If an official KTM workshop really made such glaring errors I'd FOR SURE contact KTM in Austria and let them know. I doubt KTM would allow them to continue as an official workshop.

Are you saying they returned your bike to you with an empty radiator? :eek3: Outrageous!

I know you really have to stay on top of KTM mechanicals ... the top ends especially as well as valve gear, water pumps, hydraulic clutch. Guys who really learn the bike can keep them running ... not a bike for beginners!

Good luck Mike! bier

Yup, I have a catalogue of issues with this guy and his team of KTM 'specialists', but he's still to return my engine bars so will hang back until he does so.

You won't believe it but the reason he delayed finishing what he started (he was talking about it needing a top end overhaul - but only because he sent a video clip to HQ in Austria of the valves/cam and they suggested this was what might be required..) was that as my bike is a 2005 and his mechanics are in their 20's, this meant that they were still at school when my bike was made therefore they don't have any mechanics familiar with my engine and so no one would commit to quoting. When I told him I had no faith in his shops abilities and would take it elsewhere, the funniest thing he said was if I can find someone familiar with the engine, the mechanic would need to be in the 'elderly region' haha.

Scary huh?

Anyway, it's going great now :) and for a fraction of what I'd likely have had to pay this guy

You're very lucky to have found a good guy you trust! Treat him well! bier

Good luck with the KTM!

(I still hope you'll let KTM know ... if not, things will never get better and others will be screwed by this clown )