When troubleshooting a ZX7R, first start with the fundamentals. These simple trials can work for any engine. All engines need three  basic things to run fuel, spark and air. These simple matters can cause your Kawasaki ZX7R to not start up or run poorly.

First start off with the fuel Withdraw the hose off the tank and make sure the fuel is flowing properly. Some bikes will have  to turn the fuel selector to prime, not on, or fuel will not flow.

Take a flashlight and look down into the tank, is the fuel varnished or is there dirt in the tank? Older Kawasaki ZX7Rs had a  problem with tanks rusting inside and would plug the screen up inside the tank. Fuel delivery may still be a trouble but we  will come back to that later.

Next Remove the spark plugs, you may need to Withdraw the tank to reach them. Inspect every spark plug as you take them out.  All the spark plugs should look the same. If a plug looks white colored, that cylinder may be (lean) and not getting enough  fuel.

If you have a plug that looks wet and black, that piston chamber may getting too much fuel (rich) or not sparking good. Remove all  the spark plugs and snap the plugs back into their wires.

Set the spark plugs on the engine so that they can ground themselves. Crank the motorcycle over and watch the plugs for sparks,  preferably somewhere dark. Make sure you look at all the plugs to make sure they are all sparking.

If one spark looks down  check the wire and plug, if old or worn replace them. If their is no spark the coil may be bad.If you have any test equipment  such as an ohm meter, you can find out what the resistance reading should be for your bikes coils.

This way you will know for  sure if the coils are o.k. If the ignition system looks fine move on to the carburetors. First, if the bike has not been  maintained recently (a trouble in itself) make sure the carbs are synchronized. To do this you need a vacuum gauge made for  this. Withdraw the small rubber plug located ‘tween the carbs and the cylinder.

Attach the gauge and take the readings from for each one piston chamber. Replace the caps when not measuring or it won’t run right. Adjust  the throttle screw or linkage for that carb until they all read close to one another. Refer back to inspecting the spark  plugs. If one cylinder looked lean or rich check all hoses for cracks and air leaks. If the ZX7R has not been run in awhile  the carbs may be (gummed up). Withdraw the float bowl off the bottom of the carb.

Look in the bowl for dark varnish looking gas. If the fuel looks dark you will probably have to Withdraw the pilot and main  jets and carefully run a wire through the center hole to clean them out. Be careful to not bend the float as the height needs  to be correct to run well Also. Check that the small needle attached to the float between the pivot point, is moving up and  down.

If it doesn’t move smoothly the carb will not fill up with gas or will run low as your driving down the road. Make sure you  check the battery Also, if they become down the ignition system won’t have enough power to keep the motorcycle running smoothly. If  you still haven’t found anything make sure you valve lash has been checked at the correct mileage intervals. If not this can  cause many problems with the way it runs.

As Well you can screw a compression gauge into the spark plug holes and check that they are within 5% 10% of for each one other. If one  is way down you have a serious trouble either with the pistons, bore or valves. This should be a good start to finding a  general problem with your Kawasaki ZX7R.



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