FCR-MX for an LC4e

djchan · 05-28-2008, 08:16 PM

I have a chance to buy an FCR 39 for my LC4e at a pretty good price. It's from an '07 KTM 250SXF. Can anybody tell me if this is a good/easy fit for my E? I understand there will be jetting changes - but is this a suitable donor carb?

Thanks
Dean

meat popsicle · 05-28-2008, 08:24 PM

Shall we assume you are buying the Hi-Flow head that has been massaged by the hands of creeper?

You bastage, I would have bought that just as soon as I needed it...

I don't know if the 250SXF will have the gear the creeper recommended in his thread on putting an FCR39 on his LC4, but it will be close enough eh? Might want to check out the MX, hot start, um other FCR crapola to see if it is the model for you.

Review creeper's thread (indexed under "creeper defects!" if you need search terms) and you should have your info. BTW, they say the 39 is the carb to choose if you are not a desert racer.

halfcab · 05-28-2008, 10:14 PM

I'm not sure if there is any difference in 39 FCR for the 250 from the 400/450/525. I swapped a 39 FCR MX II from a 06 400 EXC to my 01 LC4 and it was simple bolt on, nothing else was needed.

Zerodog · 05-29-2008, 07:32 AM

Yes that should be a good carb for your bike. Easy is a question of patience. But you will already have your bike pretty ripped up to do your head. So go for it. The FCR is a tight fit but it does fit. You might need to make a custom dent in your exhaust to make the pump fit.

Parts you may or may not need are, the front side bolt on intake flange. I had to get one for mine. It is cheap and you can get one for an LC4. Throttle cables: Get some from any FCR equiped KTM and you will be in good shape. Some guys have made the stock LC4 cables work. I have no idea how though. The straight cables make for an easy fit.

You don't need the hotstart, or the TPS. Your choke cable will fit right in where the FCR push pull button is with a small mod to the cable end.

djchan · 04-05-2009, 10:59 AM

Hate to resurrect such an old thread but... the FCR39 off of the 250SXF has the fixed intake/airbells. I won't be able to buy the interchangeable flanges. Is this a dealbreaker or can sudco come up with boots to make it work? I checked with the owner and the OD of the airbox side is 55mm and the head side OD is 47mm. Anybody know the corresponding sizes from an FCR39 that fit up easily on the LC4?

Thanks
Dean

Kemosabe · 04-05-2009, 11:58 AM

You may just want to pass on any fixed bell carburetors. Usually the air intake side is to small. I made the same mistake a few years ago while trying to upgrade to the FCR for my 640.

djchan · 04-05-2009, 02:54 PM

Thanks Kemosabe. I suspect in the end I'll pass on this one. I was hoping for someone to say - "I made it work. It's easy!" Doubt that'll happen.

05-28-2008, 08:16 PM	#1
djchan ^OP Beastly Adventurer Joined: Dec 2004 Location: on the border Oddometer: 1,137	FCR-MX for an LC4e I have a chance to buy an FCR 39 for my LC4e at a pretty good price. It's from an '07 KTM 250SXF. Can anybody tell me if this is a good/easy fit for my E? I understand there will be jetting changes - but is this a suitable donor carb? Thanks Dean

05-28-2008, 08:24 PM	#2
meat popsicle Ignostic Joined: Feb 2004 Location: Circumlocution Office of Little Dorrit Oddometer: 13,844	Shall we assume you are buying the Hi-Flow head that has been massaged by the hands of creeper? You bastage, I would have bought that just as soon as I needed it... I don't know if the 250SXF will have the gear the creeper recommended in his thread on putting an FCR39 on his LC4, but it will be close enough eh? Might want to check out the MX, hot start, um other FCR crapola to see if it is the model for you. Review creeper's thread (indexed under "creeper defects!" if you need search terms) and you should have your info. BTW, they say the 39 is the carb to choose if you are not a desert racer. __________________ Kronreif Trunkenpolz Mattighofen LC4 640 Its not so much staying alive; its staying human that counts.

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05-28-2008, 10:14 PM	#3
halfcab Studly Adventurer Joined: Apr 2007 Location: Dog Patch S.C. Oddometer: 645	I'm not sure if there is any difference in 39 FCR for the 250 from the 400/450/525. I swapped a 39 FCR MX II from a 06 400 EXC to my 01 LC4 and it was simple bolt on, nothing else was needed.

05-29-2008, 07:32 AM	#4
Zerodog Beastly Adventurer Joined: Jun 2006 Location: SLC, UT Oddometer: 1,233	Yes that should be a good carb for your bike. Easy is a question of patience. But you will already have your bike pretty ripped up to do your head. So go for it. The FCR is a tight fit but it does fit. You might need to make a custom dent in your exhaust to make the pump fit. Parts you may or may not need are, the front side bolt on intake flange. I had to get one for mine. It is cheap and you can get one for an LC4. Throttle cables: Get some from any FCR equiped KTM and you will be in good shape. Some guys have made the stock LC4 cables work. I have no idea how though. The straight cables make for an easy fit. You don't need the hotstart, or the TPS. Your choke cable will fit right in where the FCR push pull button is with a small mod to the cable end.

04-05-2009, 10:59 AM	#5
djchan ^OP Beastly Adventurer Joined: Dec 2004 Location: on the border Oddometer: 1,137	Hate to resurrect such an old thread but... the FCR39 off of the 250SXF has the fixed intake/airbells. I won't be able to buy the interchangeable flanges. Is this a dealbreaker or can sudco come up with boots to make it work? I checked with the owner and the OD of the airbox side is 55mm and the head side OD is 47mm. Anybody know the corresponding sizes from an FCR39 that fit up easily on the LC4? Thanks Dean

04-05-2009, 11:58 AM	#6
Kemosabe Perpetual Adverturer Joined: Nov 2006 Location: Gods Country OR Oddometer: 124	You may just want to pass on any fixed bell carburetors. Usually the air intake side is to small. I made the same mistake a few years ago while trying to upgrade to the FCR for my 640.

04-05-2009, 02:54 PM	#7
djchan ^OP Beastly Adventurer Joined: Dec 2004 Location: on the border Oddometer: 1,137	Thanks Kemosabe. I suspect in the end I'll pass on this one. I was hoping for someone to say - "I made it work. It's easy!" Doubt that'll happen.