Yesterday was the day of the carbs!

What a nightmare.

Only around 5 of the 16 screws came off with a screwdriver. The others had to be removed by unconventional methods

Once inside, the carbs were full of rust deposits. I managed to get the float itself off, but i couldn't get any of the screws off that hold the float oring - but I didn't think that was my rich running problem - or is it?

I changed the main jet oring and used carb cleaner to clean the inside of the carbs and the jets.

One strange thing which I need resolved.. Only one of my mixture screws is visible. The other 3 have been filled in with some form of filler.. On 2 of them, it feel like a screw/thread is sticking out by around 5mm and is covered by the filler too. Is it common in Japan to have these filled in for regulations?

Once the carbs were back on, the bike ran and idled nicely at 1500rpm. Needing choke to start and seemingly responding quickly to choke. But as soon as I Rev it with the throttle, it bogs very slightly, but the revs hang. If I Rev it to 6000rpm, for example, it comes down very slowly but settles at 3000rpm.

Why does it always settle at 3000rpm once revved, yet settles fine from just using choke?
Is this a sign the mixture screws need turned? If I can access them..
Is it a problem with air getting in/vacuum?

My bike has been modified with a yoshimure, K&N filter and all the needles are on their highest notch (towards the tip of the needle)

I would really appreciate any replies, I'm pretty lost with this one!
Thanks
Edit: It ran and revved with no hesitation at all before touching the carbs, I just believe it was running rich

It depends on if its a race can or original Yoshi db silenced can, is it 2" through out or has it got a smaller diameter inside pipe.
If 2" them you usually need to lift the needle one notch, so you would move the clip towards the tapered end.

Regarding mixture screws set it to stock and see how it goes, they usually close.

I will go have a look and another fiddle!

Why do you think it then settles at a higher idle once the throttle has been blipped?

I'll let you know how I go, thanks

Started the bike up again - Seemed to be almost normal, without touching anything.

Left it, came back a few hours later and the revs would hang at 4000rpm or so and not come back to idle. Used WD40 to check for leaks, but nothing seemed to be obvious. Seemed to be running lean.

Came back the next day and started it, it was almost normal again, revving almost perfectly and only hanging around 2300rpm, but settling at around 1500rpm after a couple of seconds. No idea why..

It seems to have been the same since, but absolutely no idea how it could almost 'fix' itself.

Running very slightly rich, but temp gauge works and I believe the fans do too. Better than lean running

Never took the carbs off again, didn't touch the mixture screws as they are covered in some form of sealer. Only managed to replace the main jet oring and it seems to be working!

Happy enough for now at how it runs. No doubt I'll have a few headaches in the future and I know where I'll come running


Thanks a lot for the help, this forum is great

Now to get some miles, or should I say kilometres, under my belt and a few pictures