KTM LC4 (640) Thread Index

[640 Armageddon]

Originally Posted by faustinoeldelbarrio

I also took down the left light, and noticed there is a spot where a bolt might go, but i am not sure if there should actually be something there. The left light actually has a threaded hole that matches the spot I signaled in red in the next picture:
Anyone has any opinions on these issues?

My 2002 was exactly the same, the bolt was missing. I bought a second set of headlights on ebay and there is a vibration dampener there. This is the same dampener as the one used in the light support bracket.
I used to run the lights without this dampener and nothing weird happened, I have LED's now so

D.

[faustinoeldelbarrio]

Thanks to both of you, I'll consider buying the dampener to give extra support for the lights.

[warewolf]

Originally Posted by Boon Booni

Maybe someone did some shad tree porting/polishing, though I've read that the porting and polishing from the factory looks poorly done.

"Looks" being the important word. There is no correlation between looks and flow. Some of the roughest porting generates great flow characteristics. Only the flow bench (or dyno) can tell you what is "beautiful". :cool:

[gunnerbuck]

This hole is unused on the left side of the framework, on the right side it supports the horn and wiring support...

I use these on both sides to bolt my LED light support brackets on, it keeps them tucked in nice and tight out of harms way as pictured below...

[bmwktmbill]

Originally Posted by beek-02

Hi Bill,

I've worked on quite a few bikes , cars, etc. Have a pretty fair working knowledge of how motors work but cannot figure out how bad valve guides/seals could continue to a bubbling radiator? Not questioning your knowledge just looking for some enlightenment.

Beek

Sent from my SCH-I535 using Tapatalk 2

Beek,
Please, you should question my knowledge!!
Like you I have worked on a little bit of everything including people as I am a nurse.

As for the LC4, I think possibly failing valve guides and seals allows engine compression into the top of the engine forcing engine oil into the air box. If the water pump seals are also bad engine oil and air could be forced into the coolant as well.

I know that sounds crazy but I had a situation like that happen to me(I think).
I had bubbles and oil in the coolant/radiator, coolant in the oil and oil in the air box.

I thought I had a cracked head so I tested it using Gunner's method...it was not cracked. So why did I have so much oil in the air box and oil in the coolant, air bubbles in the coolant and coolant in the oil?

I rebuilt the water pump and rebuilt the head with valves, guides and seals.

All is well now.

When I removed the head the head gasket was perfect. I did replace it.

bill

[Low594]

Originally Posted by faustinoeldelbarrio

I also took down the left light, and noticed there is a spot where a bolt might go, but i am not sure if there should actually be something there. The left light actually has a threaded hole that matches the spot I signaled in red in the next picture:
,

Anyone has any opinions on these issues?

My headlight has that dampner, but it secures to a bracket just inside of where you outlined, not visible in this pic.

[hAjPR]

I read somewhere that the KTM speedo can be modified that the digits of Trip 2 become the same size as speed digits? Can anyone advise, please? It's 640A '07 plus I got the tripmaster switch. Thanks!

[Kawidad]

I'm in too. I just bought a 2001 640 Enduro from a buddy, so I guess I've got a lot of reading to do.

[Boon Booni]

Originally Posted by Gerst

Hi all, this is a premature post on my part. But I think I have this bracket, new, in a box somewhere.... If anyone wants it I'll let it go for shipping plus a donation to Baldy. I'm posting before I confirm this as I know I'll forget about it if I don't do it now. With my current work schedule it may take a few weeks before I can dig it out and ship it. If your interested PM me, be patient and I will get back to you. Just trying to help out an inmate and ADV which has given me so much.

Gerst

Following up on this, Gerst sent me a link to some photos of the bracket he has. I'm nearly 100% certain that it is not the SW-Motech bracket, but I'm not sure if it's something else that will work on and ADV. I haven't seen it before, but I've only been at this a short while.










Anyone seen this before, and know if it will work on a 640ADV? It vaguely looks like the KTM bolt on option, but it looks like the spring would have to be routed under the stand instead of on top?

I'm about ready to have a friend weld a tab on my frame so I can run a center stand and side stand, but if this would work as a bolt on option, I'd prefer that.

Thanks..

[rxcrider]

Originally Posted by Boon Booni

Following up on this, Gerst sent me a link to some photos of the bracket he has. I'm nearly 100% certain that it is not the SW-Motech bracket, but I'm not sure if it's something else that will work on and ADV. I haven't seen it before, but I've only been at this a short while.


Anyone seen this before, and know if it will work on a 640ADV? It vaguely looks like the KTM bolt on option, but it looks like the spring would have to be routed under the stand instead of on top?

I'm about ready to have a friend weld a tab on my frame so I can run a center stand and side stand, but if this would work as a bolt on option, I'd prefer that.

Thanks..

That looks exactly like the bracket for the SW Motech side stand I had on my '97 400RXC. It would not work with a center stand and I'm not sure if it would fit a newer 640, even if you removed the center stand.

Here it is at twisted throttle:
http://www.twistedthrottle.com/sw-mo...nduro-rim-size


It is an automatic up stand so watch your shins when you lift the bike off the stand. Also keep the pivot point clean and lubed. With the spring mounted on the inside, any play that develops allows the stand to be pulled in and eventually the foot starts rubbing a groove in the swing arm. It also doesn't tuck in very well or pul up very high so it is prone to getting dragged through the mud if you are in a deep rut.

[bmwktmbill]

Originally Posted by rxcrider

That looks exactly like the bracket for the SW Motech side stand I had on my '97 400RXC. It would not work with a center stand and I'm not sure if it would fit a newer 640, even if you removed the center stand.

Here it is at twisted throttle:
http://www.twistedthrottle.com/sw-mo...nduro-rim-size


It is an automatic up stand so watch your shins when you lift the bike off the stand. Also keep the pivot point clean and lubed. With the spring mounted on the inside, any play that develops allows the stand to be pulled in and eventually the foot starts rubbing a groove in the swing arm. It also doesn't tuck in very well or pul up very high so it is prone to getting dragged through the mud if you are in a deep rut.

Guys,
I have lowered my 640a so the center stand an kick stand have been either shortened or bent to function properly and to hold the machine at the proper angle.

The tubing is good quality and if heated, bent and cooled slowly the strength is not affected. You can also braze on the tubing if you want to add different feet or other accessories.

Rustolium grey paint is a good match to KTM frame grey.
bill

[Low594]

I just changed the 1piece Throttle Assembly/Right Control Pod out for the Pod from a 950(not PlugNPlay) and the independent Throttle from a 250XCF. I did this so I can adjust the cable angle without affecting where the starter button sits. The following I posted in my build thread!

Originally Posted by Low594

So I was able to ride the bike today, just down to our weekly coffee. Only about 6-8 miles round trip. The throttle changes were so drastic, it seemed like a whole different bike! Super crisp response and return to idle! It was probably a combination of things, not sure what made the biggest differences. Could have been: questionable old cables, old lube/oil (2 yrs since last lubbed), good new cables, G2 throttle sleeve, fresh cable oil or the Dow33 lube on the throttle tube/assembly.

I should have compared the size of the throttle tube cams. The G2 was marked K100, which lists as stock, but for a 2008 250XCF, not a '99/'01 640A!

Here's what was used:
-'08 250XCF Throttle Housing (77002010100)
-G2 K100 Throttle Tube kit
-'05 640A Throttle Cables
-Smart Parts SL33K/Dow33 lube (yes, paintball lube!)
-Cable Life lube

This reminds me, that my clutch and decomp cables are long over due for a lube!

BTW, I've got lots of changes going on, in prep for a trip to Death Valley in a month and a half!

[Boon Booni]

Originally Posted by rxcrider

That looks exactly like the bracket for the SW Motech side stand I had on my '97 400RXC. It would not work with a center stand and I'm not sure if it would fit a newer 640, even if you removed the center stand.

Here it is at twisted throttle:
http://www.twistedthrottle.com/sw-mo...nduro-rim-size


It is an automatic up stand so watch your shins when you lift the bike off the stand. Also keep the pivot point clean and lubed. With the spring mounted on the inside, any play that develops allows the stand to be pulled in and eventually the foot starts rubbing a groove in the swing arm. It also doesn't tuck in very well or pul up very high so it is prone to getting dragged through the mud if you are in a deep rut.

You nailed it, thanks.

[Mo-Tarded]

Originally Posted by Mo-Tarded

Katrina has developed a leak when the gas is "On". Also have a slight hesitation mid-range (feels like a fuel starvation). So I'm going in... (Again).

So I got the BST parts marked with a '#' kit. Pulled the carb off, found nothing remarkable... R/R'd all the elements in the kit, put it all back together, temporarily hooked up the tank, turned on the gas and it's leaking worse.

So I pulled the float bowl off while the carb is on the bike and of course the float bowl frame and floats essentiall off/out.

I put the float frame back up into the fuel intake seat and turned the gas on and toggled the floats up and down. It was still leaking gas in the "Up" position. The only other leak path would be around the rubber "O"-ring around the float bowl frame insert into the gas intake itself.

Went to the local H/W store that has a bunch of rubber "O" rings and found one to fit. R/R'd the one on the frame and repeated the above. No leak...

While I found the solution, the problem is the "O" ring that failed (dried/shrunk/fatigued) is NOT in the "#" kit. It comes with the float bowl/frame assy.

It's all back together and runs flawlessly through the entire power band.

[Low594]

Originally Posted by Mo-Tarded

So I got the BST parts marked with a '#' kit. Pulled the carb off, found nothing remarkable... R/R'd all the elements in the kit, put it all back together, temporarily hooked up the tank, turned on the gas and it's leaking worse.

So I pulled the float bowl off while the carb is on the bike and of course the float bowl frame and floats essentiall off/out.

I put the float frame back up into the fuel intake seat and turned the gas on and toggled the floats up and down. It was still leaking gas in the "Up" position. The only other leak path would be around the rubber "O"-ring around the float bowl frame insert into the gas intake itself.

Went to the local H/W store that has a bunch of rubber "O" rings and found one to fit. R/R'd the one on the frame and repeated the above. No leak...

While I found the solution, the problem is the "O" ring that failed (dried/shrunk/fatigued) is NOT in the "#" kit. It comes with the float bowl/frame assy.

It's all back together and runs flawlessly through the entire power band.

Great timing! Mine just started doing the same!