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Hi
I have noticed that my speedo indicates some 5-10% too high, i.e the the needle shows 120 km/h when i'm actually travelling around 112 km/h according to my GPS.
In my former 240 (which had an exact speedo!) the rev counter was erratic and that was due to a faulty trimmer. I hooked the rev counter up to a signal generator and replaced the trimmer with a resistor which achieved an exact indication. (Math; 3000 rpm equals 50 r/s. 4 cyl, 4 stroke engine equals 50*4/2=100Hz)
However, does anybody know if there is a trimmer inside the 740 speedo as well? Calibration should then be just as easy using the signal generator. I just don't want to dismantle the instrument panel just to find that there are no calibration possibilities!
TIA!
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