Hi, I'm now the proud owner of a 1988 cbr 600 fj and I'm wondering if anyone else out there has had a similar problem to me, I'd appreciate your advice. Runs fine on 2000 revs but when I open the throttle it dies but doesn't cut out if you let go of throttle before it's too late and then quite happily still idles. I have had the carbs off and cleaned them with carb spray and treated her to new plugs. She still doesn't seem happy though. Last owner was told by bike shop that she needed new plugs but obviously hasn't rectified problem. Was told by previous owner was running fine but he ran out of petrol and this caused the problem. I have obviously had all jets out when cleaned carbs. Could the fuel pump be an issue? I would appreciate your advice. Ta.

 

It sounds like a possible fuel delivery or voltage problem to me based on your description. I always blow compressed air through all the carb passages & jets while apart to make sure everything is clean. Assuming it's not a blockage in the carbs, I would check to make sure fuel flows freely from the petcock when open. It wouldn't hurt to pull the petcock & clean the screen and replace the fuel filter either. I would also check the battery voltage while running both at idle and 4-5k rpm and make sure the charging system is working properly. The specs are in the manual, but if you don't have over 13v while running the ignition system can malfunction and cause this type of problem also.