Mk1 bandit 600 dropping a cylinder

[Olivernoob]

Hello everyone, recently bought a bandit 600. Rides perfect t
most of the time however intermittently it will drop a cylinder, if I ramp open the throttle it almost clears itself but after half a mile or so it will bog down and as soon as the clutch is pulled it will die. Pull over attempt starting it's a bugger, stick it onto prime and fires up no problem. Plugs are good, recent oil and filter change. I'm thinking maybe a sticking float valve but I'm wondering if anyone had any ideas before I take the carbs off?

[RhynoCZ]

Starting only on PRIME would suggest the fuel tap needs rebuilding. If it's a vacuum tap, then I would think, in combination with the lack of fuel flow, it could cause fuel starvation at speed. Clogged fuel tank breather would also reduce the fuel flow.

Check the fuel filter, if there is any, it might be reducing the fuel flow as well. Sticking float valve would be also an option.
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'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[jaffa90]

Starting only on PRIME would suggest the fuel tap needs rebuilding,
I agree with RhynoCZ
but what happens when you leave it on prime which by passes the vacuum tap ??????

[temeluchus]

either the fuel tap needs a rebuild/replacement or the vacuum hose is shagged.
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[Snowdonia Rider]

Check the vacuum hose is actually attached and/or not pinched under the tank.
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