Having found a repaired abs brain from Tosi, he has asked me to check the charge voltage between the positive terminal and chassis st 1500 to 2000 rpm.
Having done so, the voltage shown was between 51 & 54v dc!
Surely this cannot be correct.
Before I blow anything up does anyone have an answer?

The voltage should be between 13.8 and 14.2 volts. At 50 odd volts its a wonder you have any electronics left. Remove the alternator and get it repaired it is the only thing that can produce voltages like that and do not start the bike again untill it is fixed.

crikey mr bee ....that sounds weird ......are you sure that the output of the altenator is tied to the positive of the battery durring this measurement ?

without starting the bike ...at the same point that you measured before ...what is the reading ?

tis quite common for altenators without a load (or in this case a "good" positive for feedback - load ) ..they will climb above the normal voltages we expect ...

could of the feed from the altenator to the battery lost contact somehow ....corrosion etc ????

This was measured with circuit tester on positive terminal of battery and engine block.
The bike is running fine, all electrics apart from abs.
Is there a better way to measure the output?

im amazed !... check with volts again between the battery negative and the engine block

The Bosch alternator is a three phase alternator. The DC setting measures the RMS value of the voltage so an AC component may give you the reading you are measuring. May be a blown rectifier in one of the phases of the alternator. Put the meter on a low AC setting and test. If you get any AC value above say 0.7 Volts, then the alternator is suspect IMO.

Hi there, just and idea, but if the bike is running fine I would also check the volt meter.
Best regards
JAP

could be right jap ...would love to see the setting of the meter and the meter

got a pic cleverbee ?

PHEW !!!

Panic over, re-checked the output, but this time across the terminals of the battery.....
14.08v DC @ 2000rpm.
However, positive terminal and engine casing measure 16.8v DC @ 2000rpm.
Is this correct?

measure the same .....battery negative and casing ..you could have a losy negative cable ,,,( the connection at the frame could be corroded or as we have found ...the cable needs to be upgraded to something thicker )

Well, I've upgraded the negative cable with 7mm, plus used the same gauge to bond the block, bellhousing and gearbox together.
Removed and checked alternator, those little monkey balls were a bugger when putting back on, kept falling out, but a little bit of contact adhesive to lightly hold them in place did the trick.
Thanks for all your help. 2 months to go to France, Switzerland, Germany, Luxembourg and Belgium.......!

Thanks for all your help. 2 months to go to France, Switzerland, Germany, Luxembourg and Belgium.......!
Now I am jelous have a good time and take heaps of pictures for us

Yeah they can be a real problem. I used superglue and I have heard that some use silicone. So we can add another trick to the list thanks to a very cleverbee.

I know this is not the case here but as a caution never disconnect the battery on a bike or car when it is running since once the revs rise over tick-over the alternator voltage output will soar up to as much as 100+ volts at full revs and all electronics will be fried in a heartbeat it is a very expensive lesson to learn. The same can happen due to the main battery cable becoming disconnected by a failed cable connector whilst driving.
Regards,
K-BIKE