SOS - Keihin Set up KTM 640 LC4 2003

[agent34]

Guys,

I've just got a new Keihin Flat Side kit from Show and Go.

The carby is not the MX type, just the FCR 41.

On my original one that came with the bike it has some electrical shit on the foot brake side of the carburetor. :o

Does any one know what to do with this plug/ lead/ sensor once the new carby is fitted ?

Also there is the question of the hand mounted choke leaver as well ?

I suppose that the above becomes a non event once taken off, but it would be good to get some confirmation.

Any feed back would be appreciated. :D

Ps. the fitment will begin today.

Also on another note, it have tracked down different endcaps for the Factory exhaust SM, which you buy from KTM. The end cap is a changable part that slides into the rear of the exhaust and straightens out the direction of the gas flow and is also a bigger diameter hole. The result is a better note to the exhaust and gas flow out the end. Prorider at Smithfield, NSW make the part to order if they do not have it in stock.
May be 1-1.5hp they said depend on set up and tuning. :D

thanks

[dicky]

What year is your bike?
Recent model LC4's have a throttle position sensor (TPS) on the right side of the carb. I'd trawl through KTMTalk or Supermoto Junkie fo advise on what to do with that.

dicky.

[agent34]

Dicky,

The Bike is a 2003 Model.

The carby is in the bike with a few sore fingers and some patients.

The kit from show and go includes a new throttle hand control at the handelbars. The new cables have a wider niple on the end that connects to the hand control. Hence when you buy the kit they give you a new hand control body to fit to the cables.

You can use your old one, you just have to file down the nipples on the end that go into the hand control. The Old KTM hand control has a narrower socket and the new nipples are too wide.I had to find out the hard way after i stripped the thread in the new hand control which made the new hand control no good. Must adapt the old on DOH!

Bike Starts and and idles, gives the battery a hard time though first off. Pull out spark plug and trun over motor to prime carby.

There are Three cables/ plugs that are not being used now with the new carby;- Mental Check Must read Manual !

Choke cable - runs off hand control
Two sensor - electrical, may be TPS, and the other seems to be a vacum sensor. There was a braket that held it to the side of the head.

Going in for valves tomorrow and fitment of bigger exhaust end cap &
Dyno on Friday.

Will Post the results if they are any good if not will banish myself from you web page.

Has anyone else got any Dyno results on their LC4 ?

cheers.

[wobbler]

Have a look on here www.ktmtalk.com

There is a lot of articles on setting this carby up and a few dyno graphs

[Wobbly]

Not sure about the KTM, but in other applications with a swtich to the FCR this has sometimes meant having to ditch the choke alltogether (not a big issue since they are an accelerator pump carb anyway)...

[voidifbroken]

I've got a 2003 ktm 640SM and put the Sudco fcr41 kit on a couple of months ago.

I used the standard cables/throttle but ditched the return cable - only hooked up the one that opens the throttle, it fitted straight on once i drilled out the hole in the fcr bracket.

The bit attached to the bracket with the vacuum pipes is just for the mikuni - it limits the rate of rise of the carb slide in the lower gears.
You dont need it.

The connector on the carb is the Throttle Position Sensor - I cable tied mine out of the way. Seems happy enough without it :)

The choke is not needed (so far) it starts no problem without touching the throttle. You can hook up the choke if you wasnt, you just need to modify the plunger on the end of the cable

Much to my surprise it started and ran OK with the out-of-the-box jetting although I do have the standard airfilter and exhaust

[Wobbly]

The bit attached to the bracket with the vacuum pipes is just for the mikuni - it limits the rate of rise of the carb slide in the lower gears. You dont need it.
:o Where's the fun in that?? :D

[voidifbroken]

Exactly

A fun Limiting Device :shock:

[dicky]

"The bit attached to the bracket with the vacuum pipes is just for the mikuni - it limits the rate of rise of the carb slide in the lower gears.
You dont need it."

Disconnecting the switch on the other side of the Mikuni carby does the same thing.
Obviuosly not needed on the FCR.

I've read that the stock throttle cables don't fit correctly with the FCR, and the replacement ones also need a different twist grip because of the different amount of slide movement.

Check out KTMTalk, if you can wade through all of the posts, the answers are in there somewhere.

The TPS is needed, but can be fooled into thinking that the throttle is always wide open.

With a Mikuni carb it pays to make sure that the TPS is adjsuted correctly, bike runs much better if it is.

dicky.

[Wobbly]

I'm assuming here that the tps is only regulating part of the advance though right?

[agent34]

Gents,

Have read the follow on treads to the original question and it seems that the bike is still ok.

Although my novice advice told you that after i stripped the thread in the twist grip, that i used my old one. This was wrong and after spending three hours, lifting the tank back off, moving cables, re positioning throttle cables to different positions in and around the triple clamp, my wife going " have you finished yet" sam my son going " I though you knew what you were doing". I realised that the old and new cables have a ever so slightly different curve in the part that lays in the twist grip.

The problem was that the curve fitted the old twist grip and worked, but as soon as i mounted it on the handle bar, lowered the tank on, the cables became bound and the slide operation was impeded. Trust me i was very frustrated indeed. :x

Fix problem, go to hardware get bolt, drill out twist grip right through to other side, cut bolt to length, screw through as hole was just under size and the bolt had a cutting edge from the grinder, once through place nut on protuding bolt part for security. :lol:

All Fixed ! :D

Now the bike has gone to the shop for the valves and there was a little thing with lumps sitting under the counter a new cam, what a surprise.

So the new addition will be a cam with more opening time.

Ye Ha !

Will let you know how the thing goes once completed next week and hopefully getting a dyno run to check output.

Cheers for now.

[dicky]

If you've got the cash, get the Akra.
On standard headers the 98dB muffler gives a good performance increase, and like you said, the stock one is an anchor.
With the Keihin and lumpy cams that you've already got, you'd need to increase the headers at least.
You can get the 625SC headers and then run whatever muffler you like, but the full Akra is the ducks guts.
Carby + Cam + Pipe = at least 10HP over stock.
Dunno if it's really going to be as fast as a raped ape, but it'll certainly outrun a cut cat.
Are you going to ride this beast on the road?
It'll make an awesome commuter bike.

dicky.

[playwme]

I got a keihin carby with the bike when I bought it that the owner was trying to sell separate. He'd already done all the hard work and gotten new throttle cables made up though. With the choke, I just removed the cable operated choke mechanism from the old carby and hooked it up, not that I've ever had to use the choke since installing.

I'm keen to know how this new cam goes. A mate in Sydney just had a schneider cam fitted to his Duke2. Is that the same model you're getting?

As for the Akra setup, they're pretty pricey aren't they? like $1200 for the can alone. I'm going to get a pipe made up by a bike nut who owns a muffler shop. Should come in at half the cost and hopefully free up the engine a bit. Wouldn't mind some feedback from anyone who has an Akra setup on their 640 and how much difference it made though.

[agent34]

Playwme,Gents

Got half my Akrapovic pipe in the mail the other day from Germany, the other half, the can will be here in 7 days.

All i can say is that if your are going to get a bloke to make a header system up then he would want to know what he is doing. Full Stop !

A muffler/ exhaust guru quoted me $900 buck to make up the header system in SSteel, I thought that this was a great deal compared to the price of a Akra was $3000. - Veto that idea quick.

Here is why

For an extra $600 that right $600 bucks i can get you a full titanium system landed in Australia.

So when you think about that the path and answer is really clear if you can spare the money, I know it dosen's grow on trees, i wish it would.

Playwme; Ive got the old SX Super moto muffler which I am taking off and will be lying around the garage. Let me know if you are interested in it. As I will be putting it on EBay once it is off the bike next week.

Dicky; I am getting very tempted to put the stock can on the back , put the blikers on and the tail lights, nuberplate holder and go and get a pink slip so that i can ride it on the road. Because i bought it from VIC i need to go over the pits and new blue slip - big effort to rego and put all the shit on the bike again. May happen, although a lot of lunatics on the roads in tin tops and not keen on the idea of going ferral with them around, most of the tin tops have no F@@@king idea at all, they shoudl all be made ride a bike prior to getting their license. Two cents worth. By the way thanks for the link to KTM talk, been invaluable in trying to get the bike set up in the carby area.

cheers for now.

booking for DYNO 28 February 2006 stay tuned

[dicky]

Agent,

The RRP of the Akra full system is somewhere around $2,890 AUD :(
You're telling me you can get it for $1,500 AUD? :shock:
Sign me up mate :)
PM me with some details.

dicky.

[playwme]

This $1500 for a full system deal sounds alright. Bike is already booked in for a custom can though and I don't want anything thats too loud as a lot of my riding is around the city and would rather not attract too much attention. Bright orange Supermoto's attract enough of that already around here. The guy doing the can is a bike nut though and he does a bloody good job. He should be able to make it a lot less restrictive but also keep a factory look and not too much of a noise increase.

Just out of interest, does anyone else have tyre marks on the inside of the can on their 640? I'm hoping this will also be fixed with a new can.

Thanks for the offer of the SX pipe though agent34. If you are sending out details of your kickass titanium deal then point them my way as well, just in case.

[dicky]

If you are using the motard as it was intended to be used, ie Urban Assault Vehicle, then when you jump things like speedbumps, roundabouts, gutters, car bonnets, the rear sometimes compresses a _long_ way and the tyre rubs on the inside of the can. Seems a bit odd as the SM is supposed to have stiffer suspenders than the enduro LC4.
I've tried twisting my can outwards to stop this from happening, but I keep getting blackies each time I go hooning (commuting).
I just accept that it's a sign of your prowess, like tyres worn well past the edge and scrape marks on the footpegs and sidestand :)
Maybe I should stiffen up the rear a bit more.

dicky

[playwme]

Yeah, figured it didn't hurt too much. Was just curious if my can was out of place. The guys at the bike shop noticed it last time they were changing the rear and asked what the hell i'd been doing to get that much suspension travel. "riding to work" was the answer.

[d_kimo]

yep ... my LC4 always had marks on the muffler ... there are some great concrete jumps around hehehehe

[d_kimo]

Agent, The RRP of the Akra full system is somewhere around $2,890 AUD :( You're telling me you can get it for $1,500 AUD? :shock: Sign me up mate :) PM me with some details. dicky.

hey dicky, was looking around for some other ktm bits and came across this ...
http://www.ktminfo.com/ktm.asp?p=10&s=1&h=2&o=3&t=15&pg=5

$US599 for headers and $US562 for muffler ... puts it at something like $AUD1600 for the full system ... might be worth a look :)

[agent34]

Well the results are in and the following is a good honest dyno run.

We got 57 hp at the back wheel on a Dyno jet dyno.

Taking into account that there is upto 17% difference in dynos and peoples claimed output, i'm pretty happy.

Sorry guys left the graph at home in the trailer will post tomorrow.

Dicky, the last part of the muffler came today and it does not look like the one in the picture with the nozzle out the back, it's looks like a T 4 exhaust. Very trick piece of equipment and much better looking than the other model.
:D :D :D :D :D :D
cheers.