MISS!!!!!!!!!!

[MABUSA]

QUESTION----I HAVE A MISS BELOW 2,400 RPM ON NO. THREE CYLINDER.  AFTER 2,400 RPM IT KICKS IN.  HAVE TOOK IT TO FOUR SHOPS BUT NOBODY CAN GET IT RIGHT.  HAVE CHANGE PLUGS,INJECTORS,COIL,INJECTOR HARNESS,BRAIN AND COMPRESS. IS LESS THAN 6 LBS. DIFFERENT IN ALL CYLINDERS.?

?

  ANY HELP WILL BE NICE.

 

[stlbusarider]

Have you checked for any vaccum leaks aroung the throttle body?

 

[WuzzaCBXRider]

Tried switching plug wires? If the miss changes cylinders its the wire. Seems odd that it smoothes out at higher revs. Do our throtle bodies have two stage jetting?

 

[stlbusarider]

There is no jet in the throttle body. It's not carbuerated. Nor does it have plug wires.

 

[omslaw]

(fsusux @ Aug. 08 2007,21:43) Which one? There were two besides this one.

I merged the two together

 

[omslaw]

 

[BA BUSA]

(stlbusarider @ Aug. 08 2007,19:35) There is no jet in the throttle body. It's not carbuerated. Nor does it have plug wires.

+1 Busa does NOT use "plug wires" or "jets"

 

[WuzzaCBXRider]

In re:

"There is no jet in the throttle body. It's not carbuerated. Nor does it have plug wires."
"+1 Busa does NOT use "plug wires" or "jets"

I'll bow to your FI knowledge compared to my carb knowledge but as it seems easy to say what it doesn't have, how about saying what it does have? I know a TB is not a carb and if the sparkplugs don't have 'wires' in the conventional sense then what transfers the juice to the plugs, magic?

 

[stlbusarider]

(CBXRider @ Aug. 08 2007,20:48) In re:  

"There is no jet in the throttle body. It's not carbuerated. Nor does it have plug wires."
"+1 Busa does NOT use "plug wires" or "jets"

I'll bow to your FI knowledge compared to my carb knowledge but as it seems easy to say what it doesn't have, how about saying what it does have?  I know a TB is not a carb and if the sparkplugs don't have 'wires' in the conventional sense then what transfers the juice to the plugs, magic?

It's a conventional DIS (distributor less ignition system) that uses coils directly on the plug. As far as fuel the injectors, they are placed in the intake above the intake valve. In his first post he says he's replaced all of these.

 

[proud dad]

(stlbusarider @ Aug. 08 2007,22:28) Have you checked for any vaccum leaks aroung the throttle body?

+1 vacuum leaks at TB can burn a valve over time.need to check that.

 

[CalgaryBusa]

I had the same type of problem with my bike a few months back. When I was changing the spark plugs I tucked a vacuum hose that went on the bottom of the air box into the frame to keep it out of the way. When I was putting it all back together I forgot about the hose. The engine had a miss at lower speeds and was running rich. Took me a few days to figure out what was going on. Check to make sure all the hoses are connected properly.

My .02

CB