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DRZ 400 SM interesting FCR issue

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Hi guys and greetings from Europe (Bulgaria).

About an year of reading those great threads, but I never wrote to you because of my bad English.

I hope someone have priceless information about my issue:

The bike is 07 DRZ400SM with full FMF exhaust system and 3x3 mod.

I put an FCR 39 slant body carb from 99 WR400 with cold start choke only.

I use the following :

150 main jet

45 pilot jet

EMN needle, 2nd - 3rd position

Eddie Mod of the AC pump (wired arms and grinded diaphragm pin)

The TPS is broken and not connected 

New stock air filter with no oil

New iridium spark plug

So the bike starts perfect, but sputters very bad on 1/4-3/4 throttle. Pulls good on wide open throttle. I even try to ride it with no cap on the filter box, but the sputter is the same. With few words: when I clutch it to go up for wheelie, it loses power and start to sputter till 3/4+ throttle. I believe it is too rich because I have zero backfire (with removed coast enricher), pretty black spark plug and high consumption of fuel. I tried second and third position of the clip-the sputter stays. I tried OBDUT needle (wr400) on first position and the sputters disappears but the bike looses its power (it goes almost like with the stock Mikuni). I am making tests few times per day and I am really out of ideas what to do. I guess that 1/4-3/4 throttle issues are needle problems and I read few threads about NCYR and NCYS but I can't calculate their taping, diameters and lengths to compare it with EMN needle. 

The squirt duration after the Eddie mod is 2,2-2,5 sec., the line does not hit the throttle valve.

I'll be really thankful for any further information

Thank you

 

 

 

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Hi guys and greetings from Europe (Bulgaria).
About an year of reading those great threads, but I never wrote to you because of my bad English.
I hope someone have priceless information about my issue:
The bike is 07 DRZ400SM with full FMF exhaust system and 3x3 mod.
I put an FCR 39 slant body carb from 99 WR400 with cold start choke only.
I use the following :
150 main jet
45 pilot jet
EMN needle, 2nd - 3rd position
Eddie Mod of the AC pump (wired arms and grinded diaphragm pin)
The TPS is broken and not connected 
New stock air filter with no oil
New iridium spark plug
So the bike starts perfect, but sputters very bad on 1/4-3/4 throttle. Pulls good on wide open throttle. I even try to ride it with no cap on the filter box, but the sputter is the same. With few words: when I clutch it to go up for wheelie, it loses power and start to sputter till 3/4+ throttle. I believe it is too rich because I have zero backfire (with removed coast enricher), pretty black spark plug and high consumption of fuel. I tried second and third position of the clip-the sputter stays. I tried OBDUT needle (wr400) on first position and the sputters disappears but the bike looses its power (it goes almost like with the stock Mikuni). I am making tests few times per day and I am really out of ideas what to do. I guess that 1/4-3/4 throttle issues are needle problems and I read few threads about NCYR and NCYS but I can't calculate their taping, diameters and lengths to compare it with EMN needle. 
The squirt duration after the Eddie mod is 2,2-2,5 sec., the line does not hit the throttle valve.
I'll be really thankful for any further information
Thank you
 
 
 
Replace the needle jet(emulsion tube) and set the float level at 9mm.

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Welcome to TT.  I’m sure you’ll get it sorted eventually. My only advice would be to fully inspect every part of it to make sure it’s all clean and in condition and not worn out.   Good luck.  If all else fails you can always put the Mikuni back on...

On a side note, I just ordered some decals for my CBR1100XX and they are coming from Sofia, Bulgaria...I wonder how long they will take to get to California?...

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Quote

Replace the needle jet(emulsion tube) and set the float level at 9mm.

The float level is 9mm. I'll try to find new needle jet. Do you know if I need a needle jet for this carb, or it fits from the others FCRs?

That's how it looks like

Quote

If all else fails you can always put the Mikuni back on...

On a side note, I just ordered some decals for my CBR1100XX and they are coming from Sofia, Bulgaria...I wonder how long they will take to get to California?...

I will never again use the Mikuni :naughty:

Do you know what logistic company uses the sender from Sofia, or he uses Bulgarian posts? I could go to ask for information

30726181_1899052850118847_1358154468146806784_n.jpg

30743966_1899052836785515_4172099354087129088_n.jpg

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While you're at it get a vacuum cap to replace that hose with a screw in it on your intake. It sucks when that falls out while you're riding, ask me how I know. :)

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While you're at it get a vacuum cap to replace that hose with a screw in it on your intake. It sucks when that falls out while you're riding, ask me how I know.

Just tried. The sputtering and idle speed got even worse. Today I’m trying on 3-rd clip of the EMN needle. Now will put it on the first one. IMG_1642.JPG
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Now I see that you have a vacuum controlled petcock. In one of the upper pictures it appeared to me you had a piece of hose with a screw in it to cap off the vacuum port on the intake manifold.

What you did on the carb wasn't what I was talking about. What you did will richen the pilot circuit. It can be a neat way to get control of the pilot circuit if you're having midbody gasket issues. But on a normal carb with the CE delete you just keep these two ports bridged with a piece of hose.


Sorry bring it back to the way it was I'm dumb lol. My E model has a normal petcock not the vacuum petcock and I saw the FCR on your bike without a coast enrichener. I assumed you had done the CE delete but capped the vacuum port on the manifold with a piece of hose with a screw in it. I did this at first when I did the coast enrichener delete and it just leaked air.

My bad for the bad advice. 

Edited by ClutchinChrisG

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When you get this sorted out , we want to see pictures or video from the track in Pleven.   ;)

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I decided to disassemble the carb again and what I found was that the AC pump sprays about 3+ secs ?!(I read something about 0.75-1.5 sec is normal) It has perfect timing (doesn't hit the throttle valve). As I said I made the Eddie mod step by step but this long squirt duration really worry me. 

I guess it could cause my headaches.

 

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