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DRZ 400E FCR 39mx won't idle when cold

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Hi all,

I'm having an issue without fcr39mx not starting/idling when cold. When the bike is warm it runs like a champ but to get it to start is a royal pain.

The bike is a bigbore with fcr39mx. Tuned for sea level with open exhaust.

The symptoms are the bike will never start when cold unless I prime (twist throttle once or twice) bike will run for 1-3 seconds then die. If i repeat the process 5-10 times the bike will finally start and stay running. The idle will climb as it warms and eventually I can turn the choke off and it continues to run

Valves are within spec and carb was recently removed and cleaned.

Anyone have any advise?

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Jetting specs would help, what size pilot are you running?

Has this just randomly started occurring or ever since you got the FCR?

Edited by Gsxrstuntdrz

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160 main, 42 pilot, needle 3rd clip, a/f 2 1/4 turns out, Coast enrichiner removed, and the needle in the intake removed (forgot what its called)

Has been doing it since the engine was rebuilt and the carb was installed.

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Ordered 45 pilot and new a/f screw since I've got an aluminum one. Will post results

 

good idea on losing the al fuel screw, they are rubbish.....The R&D Flex jet is the go..

You should have a 45 pilot jet installed ,

use this procedure to set the fuel screw---> http://www.thumpertalk.com/topic/271735-how-to-confirm-your-pilot-circuit-setting/

set your idle at 1800 to 1900 rpm

 you have the pilot air jet removed ? and an EMN needle installed.?

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Yes the air jet is removed and I've got the original fcr39 needle. Should I replace?

 

 EMN needle, clip 3 is fine..do as suggested in my previous post

PAJ to be removed only for TT store Fcrmx....

Edited by Craigo 485sm

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Goflossurself , you said in your first post that you had an FCR/MX , if it is and it doesnt matter were it came from , you do remove the pilot air jet . 45 pilot with the new fuel screw would be the way to go . I have a 45 in mine with the keintech screw and am in the 15 to 38 celcius range . I even have to warm it up when it gets down around the 20 mark , greg

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Yes it is the fcrmx...I'm confused why Craigo stated the paj stays in unless it's the TT Fcr. The 45 pilot and new srew are still on order so hopefully they will be in soon, for the mean time I will try with my paj in

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Yes it is the fcrmx...I'm confused why Craigo stated the paj stays in unless it's the TT Fcr. The 45 pilot and new srew are still on order so hopefully they will be in soon, for the mean time I will try with my paj in

 

Removal of the paj allows the maximum air flow to the pilot circuit, ...which is of benefit with the TT store FCRMX

Edited by Craigo 485sm
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Thanks Craigo, I'll be honest your logic doesn't make sense to me why only the TT store fcrmx requires the paj removed. But since I'm at a loss and your offering advise I'll try anything. So I tried it anyways, bike runs mint with the 100 paj reinstalled. Thanks again.

Can anyone explain the difference between the TT store fcrmx and everyother Fcr on the market

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