valve springs

I’ve recently been gathering parts for an upgrade to the BBK 750 kit. Saw that these were on sale from yamahaxs650.com. Am I asking for trouble if i purchase them? I believe they look like the “performance valve springs” listed on Mikes XS. Thoughts? Is anyone running these? Thanks...

So... my bike motor needed some work. With no money in the budget, I decided to throw in a spare motor I had. I didn't know anything about it, except someone wasn't such a good painter. Valves were gapped correctly and still are. I went on a test ride and things were going great, until I...

Using a digital caliper, my valve spring measurements (free length) are as follows: Outer Springs: 42.20 mm - 42.34 mm (Range) Inner Sprngs: 41.1 mm - 41.4 mm (Range) To check my measurements (to ensure I didn't compress springs for Free Length measurements, I set my caliper to 41.8mm...