Bf225 alternator and timing belt tension check

[James t]

Hi all - I’m planning to follow the workshop manual to check and adjust the tension on both the alternator and timing belts. However I don’t understand how to apply the specified force and measure deflection of each belt to check the tension…

Timing belt - apply a force of 19.6N and check deflection 8.8-9.7mm
alternator belt - apply force of 98N and check for deflection of 5.4 - 6.3mm

is there an easy way to apply this force (otherwise I suppose I could use a spring weighing scale or bodge something else up)

I have seen specific tools on the market but to me they don’t appear to do the right job as they interfere with the deflection being the centre of the entire span between pulleys - they apply a force between two ‘tynes’ on the tool.

 

[Blacktimes]

I recently replaced the timing belts on my twins and simply let the tensioner pull up the timing belt slack while rotating and counter rotating the flywheel (lock at maximum tension point while doing this) with a LITTLE help from the thumb as Ian suggested, but if you are not experienced or confident but a pull gauge.

 

[James t]

I recently replaced the timing belts on my twins and simply let the tensioner pull up the timing belt slack while rotating and counter rotating the flywheel (lock at maximum tension point while doing this) with a LITTLE help from the thumb as Ian suggested, but if you are not experienced or confident but a pull gauge.

thanks - that makes sense to me!