If the fuel supply is working ok, and filter is already replaced then other possibilities causing this problem can be :-------
Bad ignition triger advance.
Stuck air mass meter flap.
Bad HT coil connection.
---------How's the air filter - clean or dirty? Remove the filter and try running without filter.Just try if for checking purpose.
If it runs smooth with filter removed, then air filter is the issue.-------
The handbook warns against running without a filter in case any dirt gets sucked in, so make sure the airbox is clean before you start it without the filter. If the filter is really sticky I would suspect it does need a clean.
--------The electrical connections on the air flow meter (maf) also require cleaning or at least checking.--------
Also recheck the fuel filters position.I agree its replaced, but still remove and recheck fuel filters position.--------
There is an arrow indicating the direction of the flow.
A good pressure doesn't indicates a good flow and your engine may be starving for fuel.What fuel grade are you filling up the tank with? A lower grade of fuel may causes problems too.
Sometimes things as simple as a bad spark plug cap will generate the same problem.
Also, try to start your bike in a dark area and check if you see any sparks on the coils. You can even mist them with water (when the engine is off) and it will make it easier to see if you have a crack in the insulation.
--------Also the fuel regulator / air flow metering unit could be stiff and responding slowly, that would result in the symptoms you describe. Have you checked it is moving freely?--------Also look for a leak in a manifold, even lose clamps on the rubber stacks. The next is a bad pressure regulator, that makes the fuel richen when the manifold pressure drops off and so would make it bog on initial throttle opening.------------This can mean a few things; partially blocked fuel filter, faulty pump (worm or leaking relief valve), tank not properly breathing, ehh, no doubt there's more. Other thing might be that your cooling water temperature sensor gives a wrong signal and therefore the ECU gives too little fuel.
Take the return fuel line off the tank (extend it/other hose) and put it in a container. Then start the bike and rev her up. See if the return line keeps flowing, even if you rev it; that would secure sufficient pressure through the range (i.e. fuel pump and filter allow sufficient flow). See what that gets you.---------
This troubleshooting will help.Thanks.Helpmech.
Have the throttle sensor checked for it may have an open in it's circuitry
I believe you are having a problem with the carburetors the old fuel will cause a
buildup of turpentine and leaves a fine finish inside the floats and other parts if you
can remove the carbs and disassemble them and cleaning them with i use brake clean
or carburetor cleaner they are not hard to work with just keep in mind if a screw comes
out like say the idle adjustment screw if it comes out with say 5 full turns than it must
go back in with 5 full turners the carburetor cleaner will come with a tube so you can
get in to the hard to get places while you have the carbs off run some fuel in to a
glass container so you can see if your getting any sediments from the fuel
let me no if you have any other questions
i hope this helps you
bob
Hello old.... the problem is crud in the combustion system. I am glad you replaced the fuel. I hope you used fresh fuel as a gas can of fuel that sits all winter is deteriorated too!
Get a can of fuel additive to clean the injectors etc. I like a product called seafoam available at most auto parts stores. follow the instructions and add the correct amount to your fuel tank. After you drive about 5 miles you will clear the problem.
Another trick is to use a can of engine starter and spray some into the air intake as the engine is running. this too will dissolve the gunk that is causing your troubles. Joe
Hello
Since this bike has electronic fuel injection you will need to have the system tested for fault codes with a factory scan tool and have the fuel pressure tested, you may have a failing fuel pump, but once again the price of a new pump is astronomical and testing is vital to avoid replacing good parts.So at this point a trip to the dealer or a repair center that has the tools to do the tests I mentioned is money well spent. Once you have the electronics tested and the fuel pressure you can do the repairs yourself to save money.
Check the fuel filter and fuel pump. One of the two is either clogged or malfunctioning. The only other options that would cause this would be the Timing belt stretched or an electrical short.
ok, Those are usually the two obvious problems in these situations. It fires right up and only gives you this problem when on the road trying to accelerate. these types of symptoms indicate, to me, either a problem in the timing like the advance, a vacuum problem, or a need to clean the Carb or injectors depending on which you have. Based on what your saying I would do an RPM test and see if the problem can be reproduced without being in gear. You know the average amount of time that passes before the problem appears when driving. Your going to want to put a fan blowing in front of the motor and hold the throttle at the normal RPM you at on the road when the bike does have the problem and see if it cuts out like you mentioned. If the problem does NOT re-occur under those conditions, you have an issue in the Transmission that is causing the problem under a load. If it does, you know to look at vacuum lines and the Carb or injectors and Timing belt. If that timing belt has never been replaced there is a higher chance your problem is in that area of the bike than the rest. When the belt stretches under a load it will give you these symptoms intermittently as a warning to it getting ready to break. It is a good idea to make sure that isn't the problem before it breaks because if it breaks while running you'll bend the valves and cause a lot more damage.
If the problem can't be reproduced except under a load I would start looking at the timing and transmission.
×
654 views
Usually answered in minutes!
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.
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?
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.
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?
When several solutions are submitted by different people then it is difficult to keep up and it is very disjointed. I can only presume you are responding to my comment re whistling noise from fuel tank breathers - every bike I have ever had has done this to my knowledge and often gets worse when bike is moved and disappears when tank cap opened.
It was evident that the solution was levelled in general at various vehicles other than Kawasaki ZZR1100 but various parts were relevant and helpful.
×