I'm busy checking float height for my 3EN1 carbs (flat slide). My question is 22mm from where (datum line). My float bowls do not have a line on them, nor do they have a line under the "Mikuni" (the Mikuni line). So where do I measure from?
Thanks!

Are you sure they're "Flatslide" and not CV ... ??? Do they have round plastic tops ???

There isn't a float height as such, it's a fuel height - it probably says this in the thread somewhere. If you can find a manual for the FZR600 3HE to download the info to measure this should be in there somewhere - the engines are and carbs are similar

Sorry I meant fuel height. I found this post which was very helpful:
viewtopic.php?f=37&t=51359&p=367988&hil ... rb#p367988

Specifically:
There is either ; a large cast line half way up the bowls.
A line under the stamping MIKUNI...(known as the Mikuni line)
Or no lines at all...then it is from the gasket face.

So my carbs have neither a cast line or a "Mikuni Line", but I don't understand "from the gasket face" when measuring fuel height. It would make sense if it was float height.

Start from the beginning ... what's the problem with the bike ?

Just trying to go through the "usual suspects" for troubleshooting. Maybe I should start a new thread, but read on.
Bought the bike recently from a forum member. The issues have been well documented here in his posts, but basically it will not hold an idle and will not rev past 6000 RPM. From reading his posts he did a thorough job of inspecting and setting the carbs but i wanted to double check the obvious.
I have found a couple of other issues so far:
1. Broken wire to fuel pump - now fixed
2. Coil pack serving Cyls 3 & 4 showing resistance out of spec - replacement on the way

Check the exup is opening - I've probably said that before.
Only othe suggestion would be worn emulsion tubes

Breakthrough tonight! Your suggestion of EXUP got me thinking so I disconnected it and zip-tied it open. Well now she runs like shit off a shovel all the way to red line. Carbs still need a bit of work at idle but this is a major step forward. Many thanks!

BlueR32 wrote:Breakthrough tonight! Your suggestion of EXUP got me thinking so I disconnected it and zip-tied it open. Well now she runs like shit off a shovel all the way to red line. Carbs still need a bit of work at idle but this is a major step forward. Many thanks!

I had a 3en2 that was like that - I sold it before I got to the bottom of it but my theory was the valve tolerances had closed and the extra back pressure of the exup was causing the bike to effectively stall, it's a bit of a job to do but I'd say to check the tolerances. The other explanation could be the carbs running rich, so when you open the exup the mixture is weakened .... if these were replacement carbs they might have come from a bike with the exup removed.