DRZ400SM '07 - no power after jd jetting

[Mad_Turnip]

Hi,

 

I have an Suzuki DRZ400SM '07 bought last year. I had some issues with the power. I saw that i have an 3x3 hole but until yesterday i coudn't check the carburetor. I ordered JD Jetting and the fuel screw. Yesterday i took off the carburetor, changed the needle (blue one, clip on 4th position), main jet 155, pilot jet 25 and put the o-ring and the little spring from the old fuel screw to the new one. I didn't noticed the little washer on the fuel screw. It's important ? I'm ordering a new one.

 

After putting all back together, i was able to start it quite easy. But when i tried to see if the fuel screw it's working, it's doing nothing. No chanhe in RPM or anything.

 

After that i tried to rev it on Neutral, it had another engine sound, no more vibrations, sounded good. But my big issue was when i wanted to ride it. First gear, started rolling, then i wanted to accelerate it, and nothing, even at WOT ... nothing .... instead of being like a "raped ape" (seeing reviews here after JD Jetting) it's like a dead poney ... 

 

I'm located in Bucharest / Romania, low altitude (about 250ft - 60-90m) and in the summer it's quite hot here, about 100F or over (about 40C).

 

Please advise about the jetting settings and maybe other issues .. can a bad jetting kill it like this ?

 

Thanks ?

[Anthon Berg]

From memory, the Euro bikes want the 22.5 pilot jet (because of the different pilot AIR jet that's in them)

Stock motor and exhaust otherwise?

[Mad_Turnip]

stock motor, stock first stage of exhaust, only the final part it's an arrow: this it's the real bike : http://bikeshop.ro/uploads/file_436495_phpV2c0vs.jpg

[hinksy]

Turnip , I think your jetting would be very close , is your carby a mikuni or keihin ? It sounds like your pilot circuit is working but not the needle . If its the mikuni then the diaphragm and its seating is crucial , make sure the rubber is stretched over the lip on the top of the carb . Also make sure the needle is correctly setup with the right amount of spacers and locked into place . There is also an o-ring in the top of the carby , was that put back in place ? Another thing could be the throttle cables , make sure they are correctly attatched and working properly . greg

[Mad_Turnip]

Hi hinksy,

 

my carburetor it's her stock mikuni. Yes, the pilot it's working, but i don't know why the fuel mixture screw isn't. The needle was placed with all the spacers in place, i triple checked this. The o-ring near the diaphragm it's in place. Also the throttle cables are in place, working fine, i can rev it on neutral, but once in gear ..... no power.

 

So you're saying the jetting settings are ok ? Why the fuel mixture doesn't do anything ? Also i need the little washer in front of the o-ring for the fuel mixture screw ?

 

Can the diaphragm be the culprit ?

 

Thanks.

[ohtobias]

Check if the idle adjustment screw is all the way in. That could make the mixture screw have no effect.

[Mad_Turnip]

Check if the idle adjustment screw is all the way in. That could make the mixture screw have no effect.

it's not ....

[sdhydro]

With extended fuel screw I believe you should use the 22.5 pilot jet. Also what exhaust are you using? If stock the 155 main jet is to big. 155 main jet is for aftermarket exhaust corked (quiet insert installed).

[james509]

I think Hinksy probably has it right. Check the rubber diaphram under the top plastic cap. If it isn't sealed correctly the slide won't lift.

[Mad_Turnip]

I think Hinksy probably has it right. Check the rubber diaphram under the top plastic cap. If it isn't sealed correctly the slide won't lift.

but if the slide won't lift, i could rev it on neutral ?

[james509]

but if the slide won't lift, i could rev it on neutral ?

It wouldn't rev as well. It has to be something that you have changed. I'd check the diaphragm, the needle to make sure it didn't fall out of the slide, and the main jet to make sure it's not clogged or drilled wrong.

[Mad_Turnip]

Hi again,

 

I just received the diaphragm and replaced it. Now it's rev-ing even in load. But with the jet settings from above, it's not as crisp as it was before the jetting, and it's quite lazy until full throttle. I put back the stock pilot jet, it's starting very easy, almost with no need of stroke. (now here are over 30 Celsius degrees).

[BMWombat]

I have the exact same bike except with corked aftermarket pipe. I set mine up as follows and it works well:

 

155 MJ

22.5 PJ with extended fuel screw

Blue needle on clip 3

[plankk]

Hi again,

 

I just received the diaphragm and replaced it. Now it's rev-ing even in load. But with the jet settings from above, it's not as crisp as it was before the jetting, and it's quite lazy until full throttle. I put back the stock pilot jet, it's starting very easy, almost with no need of stroke. (now here are over 30 Celsius degrees).

 

In your original post you mention "blue one, clip on 4th position". I'd drop that back to the 3rd clip, the 4th clip is going to be rich for a stock engine and exhaust.

[ohtobias]

European models require you to order and install Pilot Air Jet #135 (Suzuki OEM part number: 09492-27010). The US-made jet kits and instructions are made with this pilot air jet in mind (it is not included in any of the kits) since PAJ #135 is found on US carburators. I think it's #165 that's installed in Europe. 

 

Get your pilot circuit correct first, then deal with the other stuff. 

[Mad_Turnip]

today i rode a little more and i could see that in lower rpm's the power is very low. it could be from Pilot air jet ?

[Mad_Turnip]

Hi again ? ,

 

Even if i replaced the pilot jet with the stock one, the extended mixture screw doesn't have any effect .... 

Edited July 23, 2014 by Mad_Turnip

[Syanur]

today i rode a little more and i could see that in lower rpm's the power is very low. it could be from Pilot air jet ?

Just like mine ( From Turkey

 

European models require you to order and install Pilot Air Jet #135 (Suzuki OEM part number: 09492-27010). The US-made jet kits and instructions are made with this pilot air jet in mind (it is not included in any of the kits) since PAJ #135 is found on US carburators. I think it's #165 that's installed in Europe. 

 

Get your pilot circuit correct first, then deal with the other stuff. 

Is there any setup for european models with PAJ#165 ??

[Mad_Turnip]

Is there any setup for european models with PAJ#165 ??

 

Seems that you can use the european model with the stock pilot jet, not the one from the kit. My question it's why the fuel screw doesn't do anything...

[ohtobias]

Just like mine ( From Turkey

 

Is there any setup for european models with PAJ#165 ??

 

Get the PAJ, it's not so expensive even if shipping costs more than the part. I'm no jetting expert, but the way I understand it the 3x3 mod corresponds to a certain carburetor setup. If you don't set up your carburetor with the same parts as the americans, you are on your own as to figuring out how large the hole in your airbox should be.

 

 

Seems that you can use the european model with the stock pilot jet, not the one from the kit. My question it's why the fuel screw doesn't do anything...

 

The pilot jet and the pilot air jet are two different parts. If you want to use the instructions that comes with the JD jetkit, you'll have to get the correct pilot air jet. 

 

Are you confident you put together the fuel screw correctly with washer and o-ring? When I first jetted my bike, the fuel screw didn't do anything either - I had to back off on the white plastic idle speed screw before the fuel screw had any effect.