Zx6r f1 carb issue

[c058y]

Hi everyone,

Rarely need assistance as I've owned this bike for nearly 12 years and on the majority of issues I've been able to work out either by using the manual or trawling the forums for similar issues although this problem is beyond my knowledge.

The bike hasn't been used much over the last couple of years although I dusted her down and gave her some TLC. Passed the MOT although runs rough when at idle.

I believe the issue is with the (excuse the non technical terminology) long carb needle from the diaphragm on carb 2 & 3. After a short period of time after start up excess fuel is fouling the plugs in 2 & 3.

I have a video which should explain more.

Any assistance grateful

[jaffa90]

How long has fuel been left in the carbs?
I was thinking 2&3 cyls share the same coil but you have coil sticks.
Do all 4 carb slides lift and drop slowly?

[Hong Kong Phooey]

Carb float needle valves knackered or not seated, or float heights wildly out would be my guess, that's some excess fuel there for that amount of revs.
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[c058y]

When all the issues started I thought I'd renew a load of parts as it had been sitting for a while, even though I had regularly started the bike, obviously is wasn't as much as it needed.

New fuel & filter
New coils & HT leads
New spark plugs
stripped and cleaned carbs, no tears or degradation in the diaphragms, slides move as they should do.

I guess the excess fuel is pushing the jet needle either due to incorrect float heights or perished valves. After serving the carbs the problem still remained.

I've now bought 4 x carb repair kit, If I'm going to pull the carbs again I'll renew all the parts in all carbs. Hopefully this should sort it?

[c058y]

It seems this over fueling issue was related to perished o ring seals in the 2 centre carburetors. Purchased and fitted kit for each carb now the original issue in the video has been resolved, YAY

Only issue I have now it that seems under fueled when riding above 7k-8k, total loss of power and bogs down even to point where it judders quite violently. Pilot screws set to 3 turns out so will muck about with these and check hoses aren't squashed etc and go form there.

Any other ideas?

[Hong Kong Phooey]

Not familiar with your model, does it have a fuel pump?
Check the flow, 0.7l per min is plenty.

Also check fuel filter, breather and petcock.

Mine was collapsed hose, easy to miss when you put the tank back down.
____________________
'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[c058y]

I have a spare fuel pump, (new aftermarket although its opposite of original) will fit that and see if any change, fuel filter fitted is new also.

I'm yet to dismantle the petcock so will strip whilst the tank is off and nearly empty.

[Hong Kong Phooey]

Confirm breather hose operation before anything, simple, common and free
____________________
'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8