Dave, that engine combo sounds just right.  I think you will be pleased with the power delivery, and the vibes should be minimal too.  I'm curious how the stock CV carb will work with the bigger engine.  BTW, the Fastman is correct about the stock airbox.  It's easy to use with aftermarket carbs.

Being able to click off 160 miles between pit stops will be sweet.  That tank looks great on your cafe.  I'm sure it will be equally nice on the Retro Thumper.  

Am I seeing things or does that Tempter have a kink-free exhaust header?  That might be a good way to install a Dyna muffler without having to procure the special adapter.  Any one have an idea what the actual model designation is for the Tempter?  Is there any sort of parts fiche on-line so we could cross check the part number for the header?

I know for sure it was sold in Japan. I find one in auction house in Japan from time to time 3 to 5k + shipping/ customs. Yeah maybe when I win the lottery !

The model designation is ST400.  I found this source.

https://www.cmsnl.com/suzuki-st400v-tempter-nk43a_model50188/partslist/

Looks like those head covers are no longer available.  They are part numbers 11171-07F00 and 11172-07F00.  Header 14150-07F00 also looks like it is no longer available.  I didn't look for the seat.  But the illustrated parts breakdowns and part numbers might help you track down some of the tidbits.

I did a cursory cross check and many of the Tempter parts are interchangeable.  For instance, all of the clutch parts seem to be interchangeable.  Same for valves, valve springs & cotters.

Anyone familiar with the CMS outfit?  I recall seeing it in one of the recent posts regarding muffler installation, the gasket/connector issue.

Dave,

I think an ST650 would be a fine street bike for an aging (but not aging-out) rider.

If you follow Classic Octane on YouTube (and you should), Taylor uses custom saddles made by Tuffside. You might want to see if they can match a saddle to your tank to give you that Tempter look.

I bought a KZ400 rear fender to graft onto the front part of the stock fender - it doesn't match up real well.

I also bought a 1981 Honda Goldwing rear fender to graft onto the stock fender - it hasn't arrived yet.

And - I think the winner is going to be a rear fender from a Moto Guzzi California.  It won't require grafting onto the stock fender - but it will require some work to make new fender mounts.  It appears to be a pretty good match to the front fender I chose and has a nice vintage look.

This looks cool. I just wish your were in a hurry!

Today I worked on the mount for the front fender.  The hoes needed for the Savage forks are a bit higher and a bit closer together than the KZ750 that this fender came from.  You can see the old holes in this photo.

I set the plugs in just a bit shy of the surface.