XJ700 Carbs

Hi all I have an XJ700 with after market pipes, K&N and stage 3 dyno. I have a bad misfire where it leaves the pilots on to slides around 5000rpm and clears totally at 6500rpm, main jet is right for the bike as It pulls great and into the red HARD. I have checked diaphrams for holes etc, I am fed up of checking Emulsion tubes :twisted: I have tried all settings on needle from slot one through to 5. it makes no difference if cold, hot or if I do it from a stand still (bowls full)

I am running correct at tick over infact I could if wanted take it down to around 500rpm

It will steam in the red and out the other side if I were brave but it is litrally the 1500 rpm between 5k to 6.5k RPM I have the problem

Any help most apreciated

 

Have you checked the float bowl fuel height using the clear tube method? I would suspect that it is a lean condition. That means either the main jet is too small or the fuel height is low. If it was rich moving the needle down should have corrected that.

 

does anyone know the exact settings for float bowls

 

3 to 4mmm below the carb body. Nick has one of the best pics so I added it.

 

Here's the Specs right out of the Yamaha Factory Manual:

Looks just like the picture above this ... don't it?

 

hm...The service manual for the XJ700N/NC states the fuel level to be 1mm +/- 1mm (0.039 +/- 0.039 in) below the carburetor body?

Float height = 16mm +/-1mm (0.630 +/-0.039in).

 

Rick, is that a Mikuni carb only the drain plug seems to come out of the bottom of the carb. I have the same detail in mybook as FinnogAngela.

Mick Faighaigh.

 

Yes. That's MIKUNI ... but, BS-35's -- like on the 900.
It looks like they use the same drawings ... almost like "Clip Art"

Good catch. At least we have it for 900; too.