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Discussion Starter #1
Does anyone know how to disable or cheat the throttle position sensor on the carbs on a 99 xrv750.
Is there a gadget that can be connected instead?
 

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Without the TPS, the ECU won't be able to correctly calculate the ignition advance required. Earlier bikes didn't have one so you could fit an earlier ignition system. Why do you want to disable or cheat it? Running different carbs?
 

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Discussion Starter #3
Yes as the engine is in a Bros chassis and the Africa carbs don't seem to work very well.I want to put the Bros carbs on as they are a known quantity and have multi position needles. also 0.5 mm bigger bore!

saw a gizmo to cheat a hornet TPS of the same era so thought there might be an xrv one.
Cheers for the reply anyway
John
 

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There must be some way of transferring the TPS or modifying another similar TPS to fit on the Bros carbs. I wonder what curve the ECU uses when the TPS isn't connected. There must be a fall-back curve of some sort just in case the TPS goes bad. If it doesn't give enough advance then maybe the static timing could be tweaked with a new timing rotor assuming the later one has a dedicated ignition timing rotor on the RHS of the motor under the clutch casing.

You could book some dyno time and do runs with the TPS fixed at different positions and see which works best. When you find out the optimum position, take resistance measurements off the sensor and replace with a couple of resistors and you're done.
 

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Discussion Starter #5
All good ideas thanks. Thought of fitting earlier ignition pulse coils but don't know if later motors would still have threads to fit them or castings that I could drill + tap to fit them.

Otherwise thought I might try to fit old style ECU and join the inputs as they enter the ECU and cross fingers
 

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the TPS gives greater advance at lower throttle openings.. if you fool the ecu into thinking you have a wide open throttle (WOT), then you will get the stock map.

so measure the resistance of the tps at WOT and put a resistor of that value in its place.. or remove the tps from the old carbs and set it to the WOT position and tape it into the loom voila :)
 

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Won't the TPS & bracket swap over?

I experimented a while back with NTV carbs on the Alp (bigger bore), the NTV carbs had the mounting points for the TPS bracket but needed tapping, other than that a straight swap (although back on stock carbs).

I have run the bike with the TPS disconnected & could tell no difference when riding......

Phil
 
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