2006 CRF450X Throttle position sensor (TPS) question

[teambft]

Took my TPS off the carb. Trying to test it per service manual.

Between blue and black wires I get 4.4k ohms, which is within spec. But between black and yellow, get less than 1k ohm. When turning the TPS slot all the way, goes to about 4K ohms max, when multimeter is on black / yellow wires.

According to calcs in the service manual, I should get about 6k ohms in idle position.

Am I testing it wrong? Possible it's a bad TPS? It's accurate to test it off the bike, correct?

Thanks.

Edited March 27, 2016 by teambft

[William1]

No, you do not test it off the bike.

Depending on the bike (battery or not) you test/set at idle (voltage) and then open the throttle fully (engine not running of course) and check resistance. Resistance at idle and resistance at WOT is the range. As you open the throttle, watch the meter for sporadic/jumping wich is indicative of a worn TPS.

[teambft]

Thanks. How does testing it on the bike versus off the bike differ? If I turn the throttle wheel with carb off bike and get min and max resistance measures?

[teambft]

Looks like I was reading the calcs in the service manual incorrectly...... Should be 4.40k ohms X .13=.572 and 4.40 k ohms X .15 = .660. So at idle between 572 and 660 ohms.

I set it with carb off the bike but when carb is back on, will find idle position and retest.

Edited March 28, 2016 by teambft

[FORMA MOTO]

.55 - .65 ohms is your range.

[ThrustWasher]

Your tps is a potentiometer, it should be tested on the carb