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Fcr 39mx help

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Hi all,

I'm hoping you guys can help me out with my Fcr 39mx. I'm having some issues with tuning and I need new throttle cables.

My bike is a 2003 drzE and the cables were a pain to fit on the fcrmx. My throttle cable snapped so I'm looking to replace with the same cables as they look longer. Does anyone knowing they will fit my bike (aka fit the drzE throttle grip)

My second question is the tuning for the fcr39. My E has a BB kit and full fmf exhaust with power core thingy. I also ride around 300-500m. I currently have a 160 main, 42 pilot and ocmn needle 3rd clip. Can anyone advise on if things correct?

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'

Hi all,

I'm hoping you guys can help me out with my Fcr 39mx. I'm having some issues with tuning and I need new throttle cables.

My bike is a 2003 drzE and the cables were a pain to fit on the fcrmx. My throttle cable snapped so I'm looking to replace with the same cables as they look longer. Does anyone knowing they will fit my bike (aka fit the drzE throttle grip)

My second question is the tuning for the fcr39. My E has a BB kit and full fmf exhaust with power core thingy. I also ride around 300-500m. I currently have a 160 main, 42 pilot and ocmn needle 3rd clip. Can anyone advise on if things correct?

Yeah .. I was constantly snapping throttle cables on my Old FCR , using twin cable's

I have no issues with the single cable SSW Throttle

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Thanks, is the 155 leaner or richer mixture?

As per the cables, the pull cable snapped because the adjustment was all.the way in.and.the alignment from.the adjustment tube.to the throttle wheel was off. I've bent the bracket so the alignment is good now but need a new cable. So are there any difference between the S and the E cables in the way they are constructed and mount? All the pictures I see of the s cables on the fcr39mx they look to be much longer

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I'm pretty sure it's too lean as is. I'm having issues of surging as well my fuel screw was turned out 3 3/4 to run properly. Also by looking at the spark plug it was very white and looked overheated

 

As listed above install a 45 pilot jet...With jet sizing and needle clip positioning, the larger the number , the richer the fuel mix...

You shouldn't have any surging with an EMN needle and 160 main jet.....only chance of that is if you are running a much bigger intake than 3"x 3" ..

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As listed above install a 45 pilot jet...With jet sizing and needle clip positioning, the larger the number , the richer the fuel mix...

You shouldn't have any surging with an EMN needle and 160 main jet.....only chance of that is if you are running a much bigger intake than 3"x 3" ..

Well I've got the stock drzE air box with boot removed. Might be slightly larger then 3x3 but not much.

There was definitely surging and if I Rev the bike in N my exhaust will glow which apparently a sign of lean mixture. The carb was a bit gummy so I have pulled it out to clean and hopefully fixes my lean issue. I'll leave the jetting for now. I'll verify the size of my pilot jet.

I suppose as well since I've installed a Big bore it makes no difference for jetting as the jetting is a ratio or air flow and the air flow will just be more?

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There was definitely surging and if I Rev the bike in N my exhaust will glow which apparently a sign of lean mixture.......

A red glowing header is to be expected with no air flow for cooling ..This is not an indicator for leanness, though surging is....If you partly tape the air intake by 1/3 is the surging better or worse or no different...

 

I suppose as well since I've installed a Big bore it makes no difference for jetting as the jetting is a ratio or air flow and the air flow will just be more?

​With big bore the piston sucks more fuel , so the correct amount of fuel is delivered with a smaller main jet, if the carb was jetted correctly pre BB install,you would usually drop 2 jet sizes with big bore ..i.e going to a 155 from a 160 main jet...

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Oh that makes sense. The carb was installed at the same time as the bigbore. The old worn out and broken Fcr flatside was replaced. As well with the bigbore install was the fmf exhaust.

I'll wait till my new throttle cables come in and I'll test covering up some of the intake. It could have been due to the buildup inside the carb

To add to the surging, it would surge at constant throttle, not acceleration

Edited by goflossurself

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UPDATE,

 

Got new cables today, S cables work great and are definitely long enough for the FCR30MX

 

Did a carb rebuild and clean and all it well. I believe the issue was the E-clip on the EMN needle, it was bet and pulling the needle up almost like it was in position 4. cleaned out a bunch of crap from the carb and is now running strong. no more surging and so much more power.

 

I do have a new issue, sometime it will stall out when I accelerate. I have not done the O-Ring mod (stupid O-Rings Kept snapping and ran out of them) and I did not advance the timing screw 1/4 turn as im not 100% sure the screw is in the stock position. would the stall be due to one of these things or is it tuning?

 

Regarding tuning, IO have read this thread many times (http://www.suzukicentral.com/forums/17-maintenance-repairs-tuning/61527-secret-world-fuel-screw.html) and I cannot get mine to do any of this. if I turn my fuel screw in it remains the same RPM till im about 1/4-1/8 of a turn away from close and the bike stalls. what am I doing wrong? should I just set it a 2 turns and leave it?

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UPDATE,

 

Got new cables today, S cables work great and are definitely long enough for the FCR30MX

 

Did a carb rebuild and clean and all it well. I believe the issue was the E-clip on the EMN needle, it was bet and pulling the needle up almost like it was in position 4. cleaned out a bunch of crap from the carb and is now running strong. no more surging and so much more power.

 

I do have a new issue, sometime it will stall out when I accelerate. I have not done the O-Ring mod (stupid O-Rings Kept snapping and ran out of them) and I did not advance the timing screw 1/4 turn as im not 100% sure the screw is in the stock position. would the stall be due to one of these things or is it tuning?

 

Regarding tuning, IO have read this thread many times (http://www.suzukicentral.com/forums/17-maintenance-repairs-tuning/61527-secret-world-fuel-screw.html) and I cannot get mine to do any of this. if I turn my fuel screw in it remains the same RPM till im about 1/4-1/8 of a turn away from close and the bike stalls. what am I doing wrong? should I just set it a 2 turns and leave it?

 

Get better quality o rings or use wire for o ring mod...

Set your fuel screw as per procedure in FAQ's...http://www.thumperta...ad.php?t=327405

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