It's possible that the new injector could be bad - remote, but not impossible. Have you tried swapping cyl# 2 injector with one of the ones from cyl 1, 3, or, 4, and checked to see if the low temp now appears one one of the others? Maybe the others are all running too hot and #2 is normal?
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Thank you for your thoughts, Felix
I´ve talked to a couple of friends and they also suggested swapping two injectors. I may try that even though it seems unlikely that two different injectors would have the same fault, but you never know until you try.
One friend also suggested an "on the bike"-measure of the output from each fuel injector over the same period of time in order to establish, if there is a significant difference in volume. It is a bit of a complicated test to perform due to the engine design, but maybe worth trying.
I have no reference for the normal temperature of the exhaust pipes on this bike, but Google claims that exhaust gasses discharge at around 780F (420C) in general. I do not know if that information is valid, though.
Thanks for the replies everybody, they are indeed appreciated!
As far as I can test by spraying carb cleaner around the throttle assembly, there are no vacuum leaks. There was a leak before, but it has been eliminated by replacing the rubber boots on the breather box and throttle assembly. Parts have been swapped around, except for the injector. Swapping that is a lot of work, and I really do not believe that the injector itself is faulty. The spray pattern is nice, it has been replaced prior to assembly, and it activates and sounds like the other ones, through the MotoScan app. I agree that it would be a good thing to test, but it involves removing the fairing, fuel tank, breather box, throttle assembly and fuel assembly, and that adds up to half a days work to chase a possible fault, that would require two separate injectors (the old and the new ones) to both be faulty. Also, the hotter-than-normal exhaust pipe and catalytic converter to me indicate that there is unburned fuel in the exhaust system. This leads me to the conclusion that cylinder number 2 does not ignite correctly and that excess fuel is ignited in the exhaust system.
I went on another test drive yesterday and the bike lacks power and acceleration. Fuel consumption is higher than it used to be. Cruising down the road at 50 mph feels almost normal, but accelerating is slower than normal and the engine has a deeper sound. I once had the ignition coil on cylinder 1 fail completely, and this does not feel the same, but more like halfway to that. Same feeling as the first test drive, after which I switched the plugs and coils on two cylinders (2 and 3).
Anyway, a friend of mine recommended a mechanic, so I guess that I will run the problem by him tomorrow. Hopefully, he has seen a similar problem before and knows the cure
As far as I can test by spraying carb cleaner around the throttle assembly, there are no vacuum leaks. There was a leak before, but it has been eliminated by replacing the rubber boots on the breather box and throttle assembly. Parts have been swapped around, except for the injector. Swapping that is a lot of work, and I really do not believe that the injector itself is faulty. The spray pattern is nice, it has been replaced prior to assembly, and it activates and sounds like the other ones, through the MotoScan app. I agree that it would be a good thing to test, but it involves removing the fairing, fuel tank, breather box, throttle assembly and fuel assembly, and that adds up to half a days work to chase a possible fault, that would require two separate injectors (the old and the new ones) to both be faulty. Also, the hotter-than-normal exhaust pipe and catalytic converter to me indicate that there is unburned fuel in the exhaust system. This leads me to the conclusion that cylinder number 2 does not ignite correctly and that excess fuel is ignited in the exhaust system.
I went on another test drive yesterday and the bike lacks power and acceleration. Fuel consumption is higher than it used to be. Cruising down the road at 50 mph feels almost normal, but accelerating is slower than normal and the engine has a deeper sound. I once had the ignition coil on cylinder 1 fail completely, and this does not feel the same, but more like halfway to that. Same feeling as the first test drive, after which I switched the plugs and coils on two cylinders (2 and 3).
This is an interesting point - especially since this fuel pump has the fuel filter built into it that cannot be replaced. But, cylinders 1 and 2 are on the same side of the injector assembly, so would you not think that cylinder 1 would be suffering from the same issue as number 2, if the pump or assembly was the source of the issue? I would also expect an error code for fuel pressure if the fuel pump was not delivering a high enough pressure. I think that the firing order is 1, 3, 4, 2 on this engine, so cylinder 2 should starve cylinder 1's fuel supply, if pressure was low in the system - unless cylinders 3 and 4 drain the entire system, leaving number 2 with insufficient pressure that is then restored, before cylinder 1 fires?
Anyway, a friend of mine recommended a mechanic, so I guess that I will run the problem by him tomorrow. Hopefully, he has seen a similar problem before and knows the cure
I had this exact problem on k1300r tried everything just as you said and the final problem was badly synchronized butterfly valves. One of them was letting in too much air and the cylinder was either not firing or misfiring because it was running lean. For 2 years i tried everything that you tried and more. And this was the problem...
If your engine works normally when gas is fully open and is erratic on idle or on low rpm you probably have the same problem.
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![Automotive lighting Rim Personal protective equipment Vehicle Metal]()
If your engine works normally when gas is fully open and is erratic on idle or on low rpm you probably have the same problem.
It is really great help you are providing. Thank you so very much!
I doubt the calibration and/or quality of my compression tester - it uses the cheap Chinese psis, I'm afraid
Anyway, I will swing by the mechanic as soon as he has time to see me. Then I will see, if he can get any kind of error codes out of the ECU. Or maybe he has some experience with this kind of problem. It is getting at bit too complex for me to handle myself. I will keep you posted.
I doubt the calibration and/or quality of my compression tester - it uses the cheap Chinese psis, I'm afraid
Anyway, I will swing by the mechanic as soon as he has time to see me. Then I will see, if he can get any kind of error codes out of the ECU. Or maybe he has some experience with this kind of problem. It is getting at bit too complex for me to handle myself. I will keep you posted.
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