KTM LC4 (640) Thread Index

what about your auto-decomp? could be bad. how many miles on the bike?

can you start the bike easier if you pull in slightly on your manual decomp lever. get the engine spinning, then let it out?

laramie

I have no idea, Look like is working since when I get the bike started, it has full compression on the piston.

36,000miles

Yea that is how I get it started, with out the decomp the engine barely spins.

What can I say, I'm sucker for punishment.

Can someone help point me in direction to the thread that address this? It's the glass on the right side of the bike. Not even sure what it's for really. I'm pretty sure I remember seeing ppl talk about this somewhere but I can't find it anywhere. It's not really even a leak, but a slight oil moisture around it has developed. Thanks!

It's the TDC viewport. It's resealing is discussed in the LC4 Index Thread...

Masochism - its not for everyone.

"good spark" meaning you can see it or ? Just wondering if trimming and reconnecting the spark plug boot might help. A fresh battery (or testing the old one) could be useful too, but with the charger on "start" well maybe not.

She won't turn over w/out the manual decomp lever - that interresting... maybe a weak starter motor? I don't recall you saying how the kicker worked for ya.

So when it DOES start, are you pulling the decomp lever and opening the throttle at all ? ..or none ?

IOW: What are you doing to (eventually) make it start ? (i.e choke setting, throttle position etc.)

I guess somehow I need to pay for the many hours I did NOT Need to work on my GS's

Yes I can see the spark when the plug is out of the engine and I do the usual test next to the block.

the Boot and/or the cable....??

I just got a new PC310 and is fully charge, Even then I can only get the engine going fast enoght (Maybe does not need to spin that fast) by using the added help of the charger on "Starter mode"

Sorry I was not clear enoght, The engine does turn over when the Decomp is NOT use but is kind of slow even with a brand new battery fully charge.

Oh it work fine (The movement that is) but is no way I hell I can start the bike with it.

So you have a big long downhill you take your bike to with trailer or something.

Then roll down and try to start... the longer the better you'll get more chances ... like twin peaks you know.

if the bike hasn't run in a while, did you take the carb out and clean everything? Probably all gunk up in there.

70% of the time the bike start I'm using the Decomp lever to get the engine going.

I try Choke on/half/off Throttle on/tiny/off but is to random to relay on it, sometimes she will start right up (half choke) and then will not start again in 30 trys.

I'm going to check the valve's again and see if I made a mistake when I set them up the last time and go from there.

I do live on top of a hill but I don't have a hitch ramp or a trailer to bring her up again, In fact I have try the push start method but never got her going that way (my GS will start in 20feet).

The carb was really clean, Better than I spect it, Maybe I just need to start from ground zero and change the settings on the carb back to stock and go from there, This whole thing is driving me crazy.

You still got the BST in there not the FCR correct?

FCR can be a pain when you leave the bike parked for a while.

Ricardo, your bike troubles sound somehow similar to what I experienced this spring.

These posts summarize the issue quite well:
http://www.advrider.com/forums/showpost.php?p=15739570&postcount=243
http://www.advrider.com/forums/showpost.php?p=15794346&postcount=249
http://www.advrider.com/forums/showpost.php?p=15858975&postcount=256

So, essentially, it was the sprague clutch that was causing the troubles. Perhaps something to consider/check as well, if no other obvious faults are to be found... (There is a great writeup on fixing the starter sprague clutch here.)

Cheers,

Tseta

Thanks for letting me know what it's called. I tried typing in TDC in my word finder in my computer on the first page of the index and couldn't find it. I've tried a bunch of other keywords that I thought originally and still nothing. Any more direction?

It’s a long shot, but...
Had a twin cylinder bike that quit on one cylinder. Good strong spark from the plug. Suspected the F.I. Lots of hassle later I changed the plug.
Ran fine.
I guess the spark just wasn’t good enough when under compression.

Struggling to find the right info.
Chain and sprocket replacment time.

I currently have a 16/45 setup on the 2004 model 640 Enduro.
I would like to be able to switch between a 15/16/17 front sprockets and keep the 45 rear.

The thing is I am not sure how many links to leve in the chain. I have a 120 link ready to go . Any ideas?


If left to my own devices i will always stuff it up..hahaha

thanks

Any suggestions on who to talk to about getting some springs for a 2006 640 Adv?

On my 99 LC4 I have 118 link with 16/45 and it looks like the 17 won't work, no more adjustment left.
I would try the the 120 and work my way down.

Well good plans gone by the wayside...lol..I know I would stuff it up

I know I had a 48 rear sprocket but something has made me think 45 for some reason...so I have a new 45 to put on the bike..I also have a 15 front but not sure if its a OEM KTM sprocket..The shoulder on the sprocket isnt as wide as the other 2 OEM sprockets...now Ill probably need to find a spacer or something..the smallest jobs end up turning into nightmares..:eek1

Havent got to the chain length yet..lol

OEM fronts sprockets are strongly encouraged.

If you measure the thickness of an aftermarket and an OEM they are not the same. The thinner aftermarket front sprockets don't allow the countershaft shoulder nut to bring enough compression onto the sleeve and the countershaft O-Ring, which makes a seal, and it soon springs a slow leak.

Dirty