I am building a cross kart with a cbr600. I am having trouble getting the engine to run properly/run at all. Do you need to have all the airbox on for it to run? I have been trying to get it to run without that.

I do not have any experience with these engines and the carbs on them. Do the carbs have vacuum lines that must be hooked up?

Cylinders 1 and 2 have these on them. Should there be a hose from them to the carbs? Cylinders 3 and 4, there is a plug in the same spot.

From how the engine is running right now, it seems that it is just running on the fuel from the choke. It will start if you combo choke it and hand choke it at the same time, and will almost idle. It will rev if you turn the choke back on after it is running, but if you even crack the throttle, it dies.

I have been looking at manuals and service manuals but have not had much luck.

I guess my biggest questions are, can the engine run without the airbox, and then, should there be vacuum hoses on the carbs?
Sorry for all the questions.

 

You can run the engine without the air box but you can expect to need to perform some re-tuning as they are designed to run with them.

no vacuum lines. That nipple shown in the picture needs a plug. It is used when syncing the carbs, no other time. It won’t run correctly as shown.

 

Ok great! Thank you so much!