Kawasaki ZZR1100 C2: Fairing has been removed - ran fine last year but now tickover rough and struggles to pull on the road. Pulls away positively then bogs down and last night on a couple of occasions even cut out - ran out of petrol feeling. The rest of the time you are struggling with throttle position trying to keep it running. All though winter started fine every time. Replaced fuel in tank just in case but same problem.

Since posting question I have replaced fuel filter. Although this is not a complete answer I have drained float bowls then started bike placing hand on fuel pump looking for indications of fuel pump action - there was action and also made sure pump relay was only switching on start - in other words relay not permanently chattering. At the same time removed spark plugs - beautiful darkish brown throughout. The bike always starts first time every time and revs freely at stand-still. I fitted new plugs and alternative coil caps - coils have been removed and coil cap mod installed, great spark. Problem only arises when bike on the road - pulls away cleanly then feels like missing or fuel issues, at worst almost cutting out but definitely not its usual smooth self. Exhaust is Motad which is as neer to standard as you can purchase on market. Since posting question I have replaced fuel filter. Although this is not a complete answer I have drained float bowls then started bike placing hand on fuel pump looking for indications of fuel pump action - there was action and also made sure pump relay was only switching on start - in other words relay not permanently chattering. At the same time removed spark plugs - beautiful darkish brown throughout. The bike always starts first time every time and revs freely at stand-still. I fitted new plugs and alternative coil caps - coils have been removed and coil cap mod installed, great spark. Problem only arises when bike on the road - pulls away cleanly then feels like missing or fuel issues, at worst almost cutting out but definitely not its usual smooth self. Exhaust is Motad which is as neer to standard as you can purchase on market.

Re fuel pump of course I do understand that I cannot guarantee that it is operating as efficiently as it should. Re fuel pump of course I do understand that I cannot guarantee that it is operating as efficiently as it should.

Problem never occurs in the garage at standstill whether held at various rev settings or revved from low to high also no smoking. In most bikes they have a timing chain which has tensioners.
Rear wheel is chain driven and runs very smoothly and with no tight spots and is aligned correctly. Brakes all operate freely.
It is still possible have fuel pump issue. Advance ******, I believe is controlled by CDI/Igniter unit therefore no vacuum tubes as per a number of older cars e.g distributer caps etc.
This model, like majority of bikes from this era, has a bank of 4 carburettors. In this case Keihen CVKD40 X4. The fact that at various intervals bike might like to cut out might indicate that it will not be an issue with just one carb. I am not sure if fuel flow from tank is just gravity feed which is then, via filter, pumped into the float bowls when required. Fuel pumps role is to maintain adequate levels of fuel in float bowls controlled by floats and cut off valves. These bikes are prone to blockage of pilot jets - poor starting etc - has always started and ticked over through winter. Also fuel goes off plus strips varnish of the inside of carbs all adds up to a potential nightmare.

I am trying to avoid stripping down carbs because with bike being 18 years old screws on carbs are a nightmare to remove. Problem never occurs in the garage at standstill whether held at various rev settings or revved from low to high also no smoking. In most bikes they have a timing chain which has tensioners. Rear wheel is chain driven and runs very smoothly and with no tight spots and is aligned correctly. Brakes all operate freely. It is still possible have fuel pump issue. Advance ******, I believe is controlled by CDI/Igniter unit therefore no vacuum tubes as per a number of older cars e.g distributer caps etc. This model, like majority of bikes from this era, has a bank of 4 carburettors. In this case Keihen CVKD40 X4. The fact that at various intervals bike might like to cut out might indicate that it will not be an issue with just one carb. I am not sure if fuel flow from tank is just gravity feed which is then, via filter, pumped into the float bowls when required. Fuel pumps role is to maintain adequate levels of fuel in float bowls controlled by floats and cut off valves. These bikes are prone to blockage of pilot jets - poor starting etc - has always started and ticked over through winter. Also fuel goes off plus strips varnish of the inside of carbs all adds up to a potential nightmare. I am trying to avoid stripping down carbs because with bike being 18 years old screws on carbs are a nightmare to remove.

The air filter is almost new.
I do not have an air flow meter.
I have coil caps instead of coils and HT leads - replaced these and plugs last night.
Fuel filter fitted correctly.
Carburetters are Keihin CVK x4. All flaps move in unison as per throttle position and vacuum slides all rise in unison also, This would indicate carbs synchronised and carb vacuum diaphragms in good state. If tank breather blocked this normally shows itself after some time on the road and may cause bike to cut out - mine continues to whistle for some time after parking back in garage.
On this model the role of the fuel pump is to maintain the fuel level in carb float bowls at necessary level as governed by carb floats and cut off valves.
If I knew how bike would run with just pipe direct to input to carbs I would give it a try? The air filter is almost new. I do not have an air flow meter. I have coil caps instead of coils and HT leads - replaced these and plugs last night. Fuel filter fitted correctly. Carburetters are Keihin CVK x4. All flaps move in unison as per throttle position and vacuum slides all rise in unison also, This would indicate carbs synchronised and carb vacuum diaphragms in good state. If tank breather blocked this normally shows itself after some time on the road and may cause bike to cut out - mine continues to whistle for some time after parking back in garage. On this model the role of the fuel pump is to maintain the fuel level in carb float bowls at necessary level as governed by carb floats and cut off valves. If I knew how bike would run with just pipe direct to input to carbs I would give it a try?

ZZR1100 does not have fuel injection it has carburettors. The fuel pump is not processor controlled. The fuel pump's role is that of maintaining sufficient fuel in the float bowls of the carbs governed by floats and cut off valves therefore it does not require much. It is true though that, despite confirming that pump is operating, I do not know if it is pumping sufficient fuel under load. I also do not know if floats and cut off valves are operating properly. At this time I am leaning towards stripping carbs for cleaning and for examination - that will mean attempting to remove 18 year old screws that have the strength of chocalate and may have already have been damaged. ZZR1100 does not have fuel injection it has carburettors. The fuel pump is not processor controlled. The fuel pump's role is that of maintaining sufficient fuel in the float bowls of the carbs governed by floats and cut off valves therefore it does not require much. It is true though that, despite confirming that pump is operating, I do not know if it is pumping sufficient fuel under load. I also do not know if floats and cut off valves are operating properly. At this time I am leaning towards stripping carbs for cleaning and for examination - that will mean attempting to remove 18 year old screws that have the strength of chocalate and may have already have been damaged.

As a temporary measure I might set up temporary fuel source and connect direct to carbs and ensure that fuel is filling each carb float bowl under gravity - hopefully confirming floats and cut off valves plus draining fuel from bowls from below to see just how much debris is in there. So far there has been no signs of fuel overflow from carbs which would indicate that floats are not damaged but I will see how it goes. As a temporary measure I might set up temporary fuel source and connect direct to carbs and ensure that fuel is filling each carb float bowl under gravity - hopefully confirming floats and cut off valves plus draining fuel from bowls from below to see just how much debris is in there. So far there has been no signs of fuel overflow from carbs which would indicate that floats are not damaged but I will see how it goes.

Hi Joe

Just been flushing the float bowls using temp fuel source at same time as opening drain on each carb in turn - no signs of debris which was a surprise. Each carb had fuel in them and flow continued which at the very least points to good floats and needle valves, There has also been no signs of carbs overflowing at any point. Vacuum slides all move in unison as do throttle flaps - reasonably balanced carbs at least by eyeball plus vacuum diaphragms in good condition.
I may have found the problem though - there does not appear to be enough fuel in the filter - it barely reaches half full. Vigorous tapping of fuel pipe and filter normally sorts this - used to do this with my old ZX10s and would not try and start unless it was very nearly full - saves battery if bike has been left for a while. If float fuel levels decrease needle valves open as float lowers, fuel pump then pums fuel from filter if there is not enough available then might pump air. This might explain why bike pulss away fine then starts stuttering and lurching sometimes pulls or missing feeling and ocasionally feels like it is going to die as if running out of fuel - petrol tank tap or tank filter blocked probably? Hi Joe Just been flushing the float bowls using temp fuel source at same time as opening drain on each carb in turn - no signs of debris which was a surprise. Each carb had fuel in them and flow continued which at the very least points to good floats and needle valves, There has also been no signs of carbs overflowing at any point. Vacuum slides all move in unison as do throttle flaps - reasonably balanced carbs at least by eyeball plus vacuum diaphragms in good condition. I may have found the problem though - there does not appear to be enough fuel in the filter - it barely reaches half full. Vigorous tapping of fuel pipe and filter normally sorts this - used to do this with my old ZX10s and would not try and start unless it was very nearly full - saves battery if bike has been left for a while. If float fuel levels decrease needle valves open as float lowers, fuel pump then pums fuel from filter if there is not enough available then might pump air. This might explain why bike pulss away fine then starts stuttering and lurching sometimes pulls or missing feeling and ocasionally feels like it is going to die as if running out of fuel - petrol tank tap or tank filter blocked probably?

Just been flushing the float bowls using temp fuel source at same time as opening drain on each carb in turn - no signs of debris which was a surprise. Each carb had fuel in them and flow continued which at the very least points to good floats and needle valves, There has also been no signs of carbs overflowing at any point. Vacuum slides all move in unison as do throttle flaps - reasonably balanced carbs at least by eyeball plus vacuum diaphragms in good condition.
I may have found the problem though - there does not appear to be enough fuel in the filter - it barely reaches half full. Vigorous tapping of fuel pipe and filter normally sorts this - used to do this with my old ZX10s and would not try and start unless it was very nearly full - saves battery if bike has been left for a while. If float fuel levels decrease needle valves open as float lowers, fuel pump then pums fuel from filter if there is not enough available then might pump air. This might explain why bike pulss away fine then starts stuttering and lurching sometimes pulls or missing feeling and ocasionally feels like it is going to die as if running out of fuel - petrol tank tap or tank filter blocked probably? Just been flushing the float bowls using temp fuel source at same time as opening drain on each carb in turn - no signs of debris which was a surprise. Each carb had fuel in them and flow continued which at the very least points to good floats and needle valves, There has also been no signs of carbs overflowing at any point. Vacuum slides all move in unison as do throttle flaps - reasonably balanced carbs at least by eyeball plus vacuum diaphragms in good condition. I may have found the problem though - there does not appear to be enough fuel in the filter - it barely reaches half full. Vigorous tapping of fuel pipe and filter normally sorts this - used to do this with my old ZX10s and would not try and start unless it was very nearly full - saves battery if bike has been left for a while. If float fuel levels decrease needle valves open as float lowers, fuel pump then pums fuel from filter if there is not enough available then might pump air. This might explain why bike pulss away fine then starts stuttering and lurching sometimes pulls or missing feeling and ocasionally feels like it is going to die as if running out of fuel - petrol tank tap or tank filter blocked probably?

Just been flushing the float bowls using temp fuel source at same time as opening drain on each carb in turn - no signs of debris which was a surprise. Each carb had fuel in them and flow continued which at the very least points to good floats and needle valves, There has also been no signs of carbs overflowing at any point. Vacuum slides all move in unison as do throttle flaps - reasonably balanced carbs at least by eyeball plus vacuum diaphragms in good condition. I may have found the problem though - there does not appear to be enough fuel in the filter - it barely reaches half full. Vigorous tapping of fuel pipe and filter normally sorts this - used to do this with my old ZX10s and would not try and start unless it was very nearly full - saves battery if bike has been left for a while. If float fuel levels decrease needle valves open as float lowers, fuel pump then pums fuel from filter if there is not enough available then might pump air. This might explain why bike pulss away fine then starts stuttering and lurching sometimes pulls or missing feeling and ocasionally feels like it is going to die as if running out of fuel - petrol tank tap or tank filter blocked probably? Just been flushing the float bowls using temp fuel source at same time as opening drain on each carb in turn - no signs of debris which was a surprise. Each carb had fuel in them and flow continued which at the very least points to good floats and needle valves, There has also been no signs of carbs overflowing at any point. Vacuum slides all move in unison as do throttle flaps - reasonably balanced carbs at least by eyeball plus vacuum diaphragms in good condition. I may have found the problem though - there does not appear to be enough fuel in the filter - it barely reaches half full. Vigorous tapping of fuel pipe and filter normally sorts this - used to do this with my old ZX10s and would not try and start unless it was very nearly full - saves battery if bike has been left for a while. If float fuel levels decrease needle valves open as float lowers, fuel pump then pums fuel from filter if there is not enough available then might pump air. This might explain why bike pulss away fine then starts stuttering and lurching sometimes pulls or missing feeling and ocasionally feels like it is going to die as if running out of fuel - petrol tank tap or tank filter blocked probably?