KTM 640 Adventure owners, sign in please...

[G-Funk]

Originally Posted by AaronJohnston

Just picked up an 03 640A from KurtW. Now anyone need a drz with both wheel sets?

Congrats ..... You'll love it ......

G.

[Laromonster]

Managed to squeeze in some dirt this weekend
Behold the artsy fartsy shot

[Sumi]

Had a rest today

[Sumi]

Before the nap:

[Dee Cee]

Hi all,
I have a 2003 640 adv and it is getting harder to start. It has always been hard to start with the button and pretty good with the leg. It seems as though the auto deco is not working as it should. The motor seems to regulaly get stuck on the comp stroke. I usually use the hand deco on the bars to get reliable results but this is not always good enough. I have been thru about three good batteries in four years and am now running an even larger than std battery ( bit of a squeeze ). Is the auto deco prone to wear in these things and if so, are they repairable, or do I have to replace the whole camshaft to get the needed part. I was checking out the thread about the starter clutch spring and that sounds like it would be a good fix as well.

All advice greatly appreciated.

[GreyDawggg]

Hi Dee Cee! I'm no expert but sounds to me like you should pop your ignition cover off and check your starter clutch out.. See if you can borrow the flywheel puller from someone.. If the sprague starts to stretch it will get harder to start and if you don't catch that early enough it will munch up your gear which is pricey.. If you catch onto it soon enough you could get away with just buying a new starter sprague and she'll start first time. When I did my engine my decamp was worn on my cam but never gave any issues and still doesn't now. The only time I hear the decomp is if the revs get way too low and you can hear that clacking noise, but then I shouldn't get stuck on the dunes and learn to ride

[clintnz]

Originally Posted by Dee Cee

Hi all,
I have a 2003 640 adv and it is getting harder to start...
Is the auto deco prone to wear in these things and if so, are they repairable, or do I have to replace the whole camshaft to get the needed part. .

The auto decomp mechanism on the cam is an extra lobe that runs on a couple of pins on the LH end of the cam:



One of these pins is prone to wear but it usually takes a few km, the above one had done 95K km. I reckon a good engineering/machining shop could probably extract & replace the pin but a new cam might be cheaper & comes with a new decomp lobe too.

If you've got a starter clutch problem you'll have a whizzy/grindy noise when trying to start, as opposed to a worn auto decomp which makes it seem like the battery is dying.

Cheers
Clint

[liferider]

Hi, mates!
As always, I rode my beloved bike all the way to my office.
As always, before living home, I have started the engine with the choke set to the level which maintain 3.000rpm, as the manual says, until the engine gains 1 line in the temp scale.
As always, meanwhile I put may garment on.
As never before... my bike started to produce that smelly grey oily smoke we all know someday must happen... but not with 45.000Kms on the clock...

I immediately released the choke, despite I was sure the smoke will keep going out of the exhaust, but... actually it stop. Then I put the engine @4.000rpm and no smoke. Then I put it @5.500rpm, this time riding to my office, and nothing!

What the heck is going on??? I know must be a reasonable explanation, and I hope it's not a severe damage...

What do you think, guys?
Thanks in advance for your help...
.
.

[Sumi]

Originally Posted by liferider

Hi, mates!
As always, I rode my beloved bike all the way to my office.
As always, before living home, I have started the engine with the choke set to the level which maintain 3.000rpm, as the manual says, until the engine gains 1 line in the temp scale.
As always, meanwhile I put may garment on.
As never before... my bike started to produce that smelly grey oily smoke we all know someday must happen... but not with 45.000Kms on the clock...

I immediately released the choke, despite I was sure the smoke will keep going out of the exhaust, but... actually it stop. Then I put the engine @4.000rpm and no smoke. Then I put it @5.500rpm, this time riding to my office, and nothing!

What the heck is going on??? I know must be a reasonable explanation, and I hope it's not a severe damage...

What do you think, guys?
Thanks in advance for your help...
.
.

Unburnt fuel maybe? The manual says to operate the choke only for a short time.. Why would you wait till it get's to 1bar?

Ah sorry:) I thought I'm in the orange crush with the LC8 with the line above

But anyway.. on my LC4 I only operate the choke for about 20 secs.

[liferider]

Originally Posted by Sumi

Unburnt fuel maybe? The manual says to operate the choke only for a short time.. Why would you wait till it get's to 1bar?

Ah sorry:) I thought I'm in the orange crush with the LC8 with the line above

But anyway.. on my LC4 I only operate the choke for about 20 secs.

Sumi,
I assumed it was oil because of its smell and its grey/light blue color. As far as I have seen, excessive fuel produces a dark grey smoke.

Choke: you are right, the User's Manual says nothing about the one temp scale bar limit to release the choke. But it was not my imagination (I hope!) so I must been told to do so at KTM Chile. And I always have been so sure about this procedure, that I have never cold started the bike without following this rule... jeeez... there are no more absolut truths left in this world...
.
.

[bike]

It needs a ton of work to make it into what I need it to be, but I've been putting on 100 miles per day commuting anyway... bought it last weekend.

excuse the crappy cell pic

[Reinhold]

Originally Posted by Dee Cee

Hi all,
I have a 2003 640 adv and it is getting harder to start. It has always been hard to start with the button and pretty good with the leg. It seems as though the auto deco is not working as it should. The motor seems to regulaly get stuck on the comp stroke. I usually use the hand deco on the bars to get reliable results but this is not always good enough. I have been thru about three good batteries in four years and am now running an even larger than std battery ( bit of a squeeze ). Is the auto deco prone to wear in these things and if so, are they repairable, or do I have to replace the whole camshaft to get the needed part. I was checking out the thread about the starter clutch spring and that sounds like it would be a good fix as well.

All advice greatly appreciated.

Just ordered a cam for my 05 with 27,000 km. Not sure of the history of the bike before I bought it. Same symptoms. To check to see if the auto-decomp is working slowly kick the bike over and you should here a sharp "click" as it engages. Mine was a muffled click (compared it to my 07 bike). Took the cam out and the pin had noticeable wear to it. Easy job to replace. Cam and bearings will cost you a little over 2 hundred US. Good luck!

[dnrobertson]

Originally Posted by Reinhold

Just ordered a cam for my 05 with 27,000 km. Not sure of the history of the bike before I bought it. Same symptoms. To check to see if the auto-decomp is working slowly kick the bike over and you should here a sharp "click" as it engages. Mine was a muffled click (compared it to my 07 bike). Took the cam out and the pin had noticeable wear to it. Easy job to replace. Cam and bearings will cost you a little over 2 hundred US. Good luck!

At 27,000 kms, I would also be inspecting the cam follower bearings. From what I know now, I would just be replacing the inlet follower bearing at 27,000. My inlet bearing was totally shot at 27000. I know others have managed to go longer than that, but it's cheaper buying a new one than having one let go and destroy the top end.

I just bought the whole follower with the bearing pressed in by KTM than messing around with punching and hoping I had done it right.

[Reinhold]

Originally Posted by dnrobertson

At 27,000 kms, I would also be inspecting the cam follower bearings. From what I know now, I would just be replacing the inlet follower bearing at 27,000. My inlet bearing was totally shot at 27000. I know others have managed to go longer than that, but it's cheaper buying a new one than having one let go and destroy the top end.

I just bought the whole follower with the bearing pressed in by KTM than messing around with punching and hoping I had done it right.

Thanks David. It looks pretty good but as you say might be an idea to replace it now. I didn't realize that you could by the whole piece as a unit. Would you happen to have the part number?

[dnrobertson]

Originally Posted by Reinhold

Thanks David. It looks pretty good but as you say might be an idea to replace it now. I didn't realize that you could by the whole piece as a unit. Would you happen to have the part number?

Part number for my 2005 640A is: 58536060144