Hi guys,
I have a cbr400rr just wondering where you guys would start and what you would do.
It started with just under heavy acceleration the revs would build fine then have a little blip then continue to build. Now below 7000 revs it really struggles to build revs and get going andat idle stalls. The engine feels very lumpy and obviously weak.
Now at 7000 revs it's coughs splutters pops and bangs then kicks itself into gear and goes like normal again. As long as I stay above 7000k revs it's fine
I changed the fuel filter thinking it was that but I'm now thinking its the fuel pump or a vacuum hose as once the engine is running at a higher speed starts to work so is obviously through its carbs pulling fuel through faster.
Any help if possible, thanks

 

Is the charging system OK? Ground connections tight, plugs securely plugged in, etc.

 

Yeah everything is tight electrical wise and charging is good

 

Clean and synchronize your carbs, and put in some new plugs.