DRZ400e Keihin FCR Tuning

The bike is a 2002 DRZ400e with Keihin FCR.  I'm at 5280ft altitude in Denver.

 

Carb settings:

145 main jet 
200 main air jet
60 pilot air jet
OCEMP needle ,clip is second notch up from the bottom
47 pilot jet
2 turns on the fuel screw

 

The bike is running good but still feels slightly lean at part throttle.  Bike starts up instantly and idles good.  I know most guys run a 45 pilot jet, and 145 main jet at lower altitudes.  This has me wondering if I have a vacuum leak or some sort of other problem. 

 

I'm inclined to bump up to the next size bigger main jet.  I was previously running the needle jet at the 3rd notch from the bottom, and moving the C clip down 1 notch to the second notch definitely helped things out, but not enough.  Any suggestions guys???

The bike is a 2002 DRZ400e with Keihin FCR.  I'm at 5280ft altitude in Denver.

 

Carb settings:

145 main jet 

200 main air jet

60 pilot air jet

OCEMP needle ,clip is second notch up from the bottom

47 pilot jet

2 turns on the fuel screw

 

The bike is running good but still feels slightly lean at part throttle.  Bike starts up instantly and idles good.  I know most guys run a 45 pilot jet, and 145 main jet at lower altitudes.  This has me wondering if I have a vacuum leak or some sort of other problem. 

 

I'm inclined to bump up to the next size bigger main jet.  I was previously running the needle jet at the 3rd notch from the bottom, and moving the C clip down 1 notch to the second notch definitely helped things out, but not enough.  Any suggestions guys???

Don't know where you got "most guys run a #145" most guys run a #160.

Pilot should be #45, you say it starts up instantly, is that instantly when cold without choke, if so your pilot circuit is too rich and you need a #45.

Bike will only start cold on the choke. Pilot jet is fine. I guess I'll go to a bigger main jet.  :D

Edited by 68lemans462

Bike will only start cold on the choke. Pilot jet is fine. I guess I'll go to a bigger main jet.   :D

 

This brings up a question or two I've had. I did a little searching, but there' so much about carbs and jetting it's hard to find any specific question.

 

My DRZ is a 2000 E, Keihin.

 

I live at 7,000. During summer the bike will be expected to run OK as high as 12,000 feet.

 

I'm not sure how it's jetted right now, just got it. I'm under the impression it's runnng pretty lean, even for this high. Exhaust is pretty hot, needs choke to cold start even when it's 70 degrees outside. I'm going to rebuild it and maybe get a jet kit depending on what I find in there soon now that it's getting too cold to ride much.

 

Here's the thing: in winter I will want to be able to run it (and have it run OK) as low as 3,000 feet (Utah desert, normally 4-6000 feet). And I could see a day when I want to go to Baja or somewhere else that's more or less sea level.

 

If I jet it for high elevation, how bad is it to run the bike low? If I'm serious about using the bike year-around do I need to plan on having two sets of jets and disassemble and re-jet it twice a year? Stock Suzuki exhaust by the way...

This brings up a question or two I've had. I did a little searching, but there' so much about carbs and jetting it's hard to find any specific question.

 

My DRZ is a 2000 E, Keihin.

 

I live at 7,000. During summer the bike will be expected to run OK as high as 12,000 feet.

 

I'm not sure how it's jetted right now, just got it. I'm under the impression it's runnng pretty lean, even for this high. Exhaust is pretty hot, needs choke to cold start even when it's 70 degrees outside. I'm going to rebuild it and maybe get a jet kit depending on what I find in there soon now that it's getting too cold to ride much.

 

Here's the thing: in winter I will want to be able to run it (and have it run OK) as low as 3,000 feet (Utah desert, normally 4-6000 feet). And I could see a day when I want to go to Baja or somewhere else that's more or less sea level.

 

If I jet it for high elevation, how bad is it to run the bike low? If I'm serious about using the bike year-around do I need to plan on having two sets of jets and disassemble and re-jet it twice a year? Stock Suzuki exhaust by the way...

If you have high elevation jetting at a much lower elevation, Then you will have to change the jetting. There is no shortcut that I know of. My 2002 came from Yuma, AZ. It ran like crap til I put the proper jetting in for the higher elevation I am living at, about 6000ft. If you want it all, get fuel injection. My street bike runs great everywhere. There are nothing you can do with carbs, except rejet.

Edited by underbike

... If you want it all, get fuel injection ... There are nothing you can do with carbs, except rejet.

 

That's kind of what I was guessing. Especially when a carb is jetted for extremes.

 

After I've had the carb out of there and worked on it I'll have an opinion about whether this is a big problem for me I guess. 

 

Thanks for the info.

The bike is a 2002 DRZ400e with Keihin FCR.  I'm at 5280ft altitude in Denver.

 

Carb settings:

145 main jet 

200 main air jet

60 pilot air jet

OCEMP needle ,clip is second notch up from the bottom

47 pilot jet

2 turns on the fuel screw

 

The bike is running good but still feels slightly lean at part throttle.  Bike starts up instantly and idles good.  I know most guys run a 45 pilot jet, and 145 main jet at lower altitudes.  This has me wondering if I have a vacuum leak or some sort of other problem. 

 

I'm inclined to bump up to the next size bigger main jet.  I was previously running the needle jet at the 3rd notch from the bottom, and moving the C clip down 1 notch to the second notch definitely helped things out, but not enough.  Any suggestions guys???

 

Use a 150 main jet and OCEMP needle , clip position 3 (always count down from the top of the needle when talking needle clip settings)

45 pilot jet

do a search on coast enrichener removal....and remove it....

This brings up a question or two I've had. I did a little searching, but there' so much about carbs and jetting it's hard to find any specific question.

 

My DRZ is a 2000 E, Keihin.

 

I live at 7,000. During summer the bike will be expected to run OK as high as 12,000 feet.

 

I'm not sure how it's jetted right now, just got it. I'm under the impression it's runnng pretty lean, even for this high. Exhaust is pretty hot, needs choke to cold start even when it's 70 degrees outside. I'm going to rebuild it and maybe get a jet kit depending on what I find in there soon now that it's getting too cold to ride much.

 

Here's the thing: in winter I will want to be able to run it (and have it run OK) as low as 3,000 feet (Utah desert, normally 4-6000 feet). And I could see a day when I want to go to Baja or somewhere else that's more or less sea level.

 

If I jet it for high elevation, how bad is it to run the bike low? If I'm serious about using the bike year-around do I need to plan on having two sets of jets and disassemble and re-jet it twice a year? Stock Suzuki exhaust by the way...

 

Re jetting an Fcr is a non carb removal deal.....so if your varying your seasonal riding altitude you will have to swap out jets and change needle setting..

for 7K and up run a 145 main jet, EMP needle clip 3 ....this should be good to around 9 to 10 K...If it starts to run fat (rich), you could get away with removing the air box door...

 

You normally try to jet for you lowest usual riding altitude so as not to run into lean running issues..

Re jetting an Fcr is a non carb removal deal.....so if your varying your seasonal riding altitude you will have to swap out jets and change needle setting..

for 7K and up run a 145 main jet, EMP needle clip 3 ....this should be good to around 9 to 10 K...If it starts to run fat (rich), you could get away with removing the air box door...

 

You normally try to jet for you lowest usual riding altitude so as not to run into lean running issues..

That is very useful info! Thanks.

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