2007 speed triple.
Symptom was flat battery feel when engine hot.
Slow turn over if at all ...40 mins later all good starts normally.
Eighteen months to find and fix this problem.
Tried all the fixes here none worked for me.
My problem is the std denso starter is a shit design.
The plate that holds the brushes is not properly earthed as is every other stater motor ive worked on.
Its simply held in place by the centre and bottom starter motor body sections.
The earth brush has no secure fix to earth in this shit design.
Problem solved by polishing the brush plate and starter body sections where the plate is mounted.
Solder a suitable wire to the earth brush where it contacts the brush plate.
Drill a suitable hole in the starter , lower aluminium body section and pass the wire through.
Install starter and bolt the wire directly to earth outside the starter body.
Result is faster starts hot or cold .
Thankyou denso for all those rides you ****ed up for me. I beat u. :-)0
Its not the starter body that is poorly earthed.
Its the plate the starter motor brushes are mounted to.
Positive brush is insulated from the starter body and bolted directly to the cable from the starter solenoid.
The earth brush however is only soldered to the brush plate which is "pinched" between starter body sections in assembly.
In effect the earth brush has no firm /bolted/ soldered fix to earth.
Over time and also powder from brush wear ..a patina forms on the starter internals and makes the loose earth contact even worse.
Add heat and lose even more current flow.
Was not an obvious solution and took a lot of hair pulling and wasted money on batteries , reg/rec , heavier battery cables etc.
Open up the denso starter and have a look ,hindsight it becomes obvious.