Starting Problem

Looks like you already know the answer, did you try charging the battery to see if it helps, but it does sound weak.

 

I've seen a fair few threads on this subject. One chap upgraded the slightly puny OEM starter and earth cables on a Speed Triple IIRC. Difference in cranking speed and start time was astonishing-all my Triumphs have struck me as a bit lazy sounding, keep saying l'll have a go with this on my Bonnie. It was on Triumph RAT forum l think by the very knowledgeable d'Ecosse.

 

Well, applying Occam's razor we should suspect the battery. I'd guess however that a starter pack gives higher cranking amps which might muddy the waters a tad.

 

The fact that the battery shows 11v briefly points to a weak battery even if fully charged

 

Hi Bob,
Check your connection at the starter solenoid, it doesn't take much to disrupt the current. this was my issue as well as having a battery with at least 210 CCA. best of luck.

 

A quick way to confirm the earth/negative path is good is to run a jump lead from the battery negative terminal directly to the starter body, then try it?

 

I would say the battery needs replacing, the Speed Triple is slow to turn over, after all it is a big lump to crank over even on a fully charged good battery, you can upgrade the starter and cable, it is not cheap however, but a new quality battery will rectify matters. I would refrain from using a starter pack, it can overload the electrical system leading to all sorts of component failures.