Fritzer108 Posted July 2, 2022 Posted July 2, 2022 A few days ago, I took my 1994 YZF750R for a spin and couldn't get it to rev above 10k rpm. Just the day before my ride, my dad drove it to his doctor's appointment with no such issues. I figured that one of the main jets must have gotten clogged, so I took it apart and cleaned it out. The main jets all seemed to be clear, but I blew the passages out with compressed air and carb cleaner just to make sure. After installing the carbs again, I have a horrible hanging idle that hangs at 7k. It revs fine now but will not come down. I checked for air leaks in the boots and the balancing lines but everything seems to be air tight. There are many threads that show up about a hanging idle, but what confuses me is how well it was running before. I will note that the previous owner deleted the EXUP system (I got it as an abandoned bike). Thanks in advance.
Fritzer108 Posted July 2, 2022 Author Posted July 2, 2022 Update: I fixed the hanging idle. One of the intake boots had a crack at the bike that I could not reach and leaked air like crazy. I patched it with some RTV sealant until the new boots would show up. The bikes idles nicely now and comes back down nicely. The issue with the 10K rev limit is still present. As soon as I hit 9-10K, I start to feel a slight stumble and it soon falls on it's face. It pulls really nicely from 2-8k. Having cleared the main jets of any clogs, I am going to see if the petcock or fuel pump are not performing as they should. I am fairly confident that this is a fuel problem, but if anyone has experience this before, please enlighten me. While I had my carbs off, I reset the float height to 14mm as I found that it had been set to 11mm.
Moderator Snakebite68 Posted July 4, 2022 Moderator Posted July 4, 2022 Well... 7k revs seems pretty high, but when my YZF1000R was idling high, it turned out to be the valve gaps.
Recommended Posts