The TPS is a voltage divider- it sends a varying voltage signal back to the ecm that's dependent on throttle opening. All TPS sensors work off of the same principle so that they will output a signal between the reference voltage sent from the ecm to the sensor and signal return(ground). Most systems use a 5v reference so let's say when the throttle is closed the wiper leg on the tps is closer to the ground end of the circuit and it sees .70v and when you open the throttle to wfo it's closer to the reference end(5V) and now the wiper sees 4.5v
That's all the sensor does so if he was able to mount it and connect the circuits correctly it should work like the oe.
If I'm not mistaken don't the F/I bikes have a catalytic convertor in the muffler. If they do(and I'm pretty sure it does) then if the bike is running super rich it will dump tons of unburned fuel in the exhaust which the convertor will try and clean up-byproduct of that process is LOTS of heat and it you continue to operate the vehicle it will cause the ceramic substrate of the convertor to melt and may create a restriction in the exhaust and loss of power.
I don't know if your bike has a vacuum port on the intake side of the head but if it does you can do a simple test for exhaust restriction. Connect a vacuum gauge and let the bike idle and record the amount of vacuum(say 17") and then open the throttle slightly to raise the revs to say 4500rpm-hold it steady at the higher revs and record the vacuum.
If there is an exhaust restriction then the vacuum will be lower at the higher revs than it was at idle(say 12") and if the exhaust flows ok it will be equal or more than the reading at idle.

Lots of things can cause over-rich conditions on f/i engines- you need to isolate the mechanical side of the engine to be sure that it isn't giving faulty info to the ecm. Remember-garbage in/ garbage out...

 

The computer is reading the position of the throttle, but different sensors probably have different resistances. Therefore if you don't have the correct one, the computer is going to think the air valve body is at a different position, which it will then send the incorrect amount of fuel for.

 

hey thanks for your comments. that brings another issue which sounds so reasonable. just because after I got the bike from the garage I have changed the exhaust pipes and installed the old one with low sound and vibration. my old exhaust is a loud and bigger one it is hand made. I couldn't install the catalytic converter correctly or maybe it is damaged during the process. I'll check it immediately. you are really great help guys really appreciated!

 

You need to realize that a tps is a potentiometer- it just sends an output voltage between the reference and ground.

 

Hey again GBAUTO,
yes I know what is a tps, just checked and tried the repair the old one but the new one is also working properly just as my new repairman friend said. and the bike is working like a clock except one condition. now we had another issue similar to the old one.

When I press the ignition key, the engine couldn't start straight away. I try like 4-5 times maybe more and 2 or 3 times out of 10 it works fine. the other times (failures to start) it just ignites, and I hear the sound of it but can't go beyond 1k RPM and the engine dies. sometimes I ignite it and it starts with low rpm and dies in 2-3 secs, sometimes I again ignite and when it starts in 900 rpm and probably gonna die, I just throttle and the engine bounces back and works fine.

we changed the fuses, spark plugs, throttle position sensor, fuel filter (Cleaned manually couldn't find it here in local places), cleaned the fuel tank also. but again a problem on the fresh start.

the problem may be the engine coals?

 

Yes, the potentiometer is basically a variable resistor. Imagine a resistor of 1000 ohms vs a resistor of 5 ohms. Would the change in final resistance change the output of the device?

Glad to hear the major problem has been resolved.

 

Hey durielk,

thanks for your comments.
actually I don't have any measurement tool to check if both TPS works equally. but the problem started when I changed it, so with this new one on each start I have the same problem. now I have just disintegrated the old tp sensor and cleaned it with wd 40 and rasped and furnished the connectors inside it. with the old (not working properly and the one I've just disintegrated) tp sensor F1 light is on when I used the new one again creating another problem on each start the F1 light is off. but the starting the bike is a problem. I'm gonna try this one, the old one that I cleaned, but in any case I wonder if I can find the original one on the net? It says 500BC2 0900A on it but I just checked this number in lots of websites including google and kawasaki oem suppliers, no result so far. or is there any way or a code that I chould delete or add to the number provided on the TPS. but definitely both TPS are not in the same number, they start with the same 500BC2 but the suffixes are not the same. this old one is 0900A and the new one is something like 9270c.

 

Looking at the figure above imagine that 5v is applied at one of the outer legs and ground is at the other outer leg. If the center wiper is rotated so that it is closer to the 5v end then the output voltage will be closer to 5v same logic applies when the wiper is rotated to the ground end-voltage will be closer to 0v. It doesn't matter what the internal resistance is because if all three legs are being used it acts as a voltage divider.
I believe that you are confusing a tps(potentiometer) with a rheostat. If only the outer leg and the center wiper are connected then as the shaft rotates it varies the resistance that the circuit sees and based on Ohms law it will create a voltage drop across that device. Tps sensors are not wired like that.

 

GBAUTO thanks for the perfect illustration.

today I've checked that gadget it is working fine. when I changed the valve the resistance between two sides also changes from 1 to 6 ohm. the middle leg which is connected to the ground means to the base of the motobike right? when I connect it the screw connecting TPS to the frame of the bike connects something? like ground connection?

but anyway with the new tps I again have the same problem today. I went to work normally and when I tried to start it after a min. it didn't start again. stopped in the middle of the road and I walked the bike to the parking lot. When I come back after 3-4 hours, again it did not start and as I tried a lot to start it, batteries started to deplete. I climbed the hill with the bike (exhausting as hell) and I bump started and it worked fine. I tried the process again and again with the normal ignition the engine dies in a sec and sometimes does not even trigger but with bump start it is working fine. the first few second it works like gonna die but after a few sec of throttle on idle It bounces back and works. still couldn't get where the problem is. another garage checked the valves (exhaust) and said they are okay no problem. maybe something about the fuel pressure? or air pressure?

 

today I changed the tps with the older one (the one I repaired) and apparently it is working okay. we cleaned the injection system it seems okay nothing strange, the pumping and spraying look good. I am gonna try the bike with repaired tps for a week if the same problem persists, I will contact the distributor in istanbul.

gonna tell the consequences here.