Just bought a 2012 Suzuki Boulevard LS650 S40. Jumped on this forum as soon as I bought it.  Lot of smart people here!  

Bike info:
1250 miles
2012
Latest inspection sticker (04/2016)
Previous Owner said it has been ridden "a couple times" since last inspection. Also told me it "runs rough".  He took it to a Honda shop and they told him the carb needed to be cleaned/serviced and it would be $300 but that the bike could ride without the adjustment.
Previous owner said he changed oil and filter ~1yr ago.

I have rode bike around.  It backfires when letting off the gas, going to a coast.  Rides smooth when accelerating and shifting through gears.  There is some bluing on the exhaust headers.  

I just got a new raptor petcock in.  Will install it and put in new gas today and give an update.

Any other recommendations for a newer bike, with low miles, not much history?

1. Should I install an inline fuel filter when changing petcock?
2. Would you guys change any fluids/do any preventative maintenance?
3. I am at sea level (Virginia Beach).  Should I jet carb? (saw it runs lean at low elevation)
4. Does this cam tensioner versy adjuster thing apply to me?

Love the bike.  

Thanks,
Keith

Kieth:

1. Should I install an inline fuel filter when changing petcock?

NO, it already has 2 filters...one on petcock and one in carb.  Additional filters can cause fuel flow problems.

2. Would you guys change any fluids/do any preventative maintenance?

Change brake fluid every couple of years, change oil when it gets dirty or old.

3. I am at sea level (Virginia Beach).  Should I jet carb? (saw it runs lean at low elevation)

Maybe, but jetting doesn't have a huge effect on the backfires when you fully close the throttle while coasting or shifting.  Learn to keep it cracked open just a hair to cut down on backfiring.  If you have a lean surge at low throttle when accelerating slowly - then you may need to raise the needle.

4. Does this cam tensioner versy adjuster thing apply to me?

Not yet, you likely need to check once you get more than 10K miles on it - 20Kif your rides are all day ones!  Short trips cause the tensioner to extend with fewer miles than long rides.

Dave

A 2012 is 5 years old ,you may want to think about replacing the tires, I 'm sure they look OK,but that rubber may be hard due to age.

If you are new to these bikes, be careful of the rear brake in panic stops, it tends to lock up. If you are on the original IRC brand tyres, be careful in the wet, or on tar snakes as some here call them. If you can afford it, contemplate replacing the rear tyre. There is a value for money Shinko, which is very popular here, although I run a more expensive Michelin Commander.

Welcome keith!
Heed the advice about being easy on the header bolts.  A small or stubby ratchet and just snug them up.  Couple fingers on the ratchet handle, not your whole hand.  Do this when the motor is cold.

Do you guys run premium gas?  Any benefits?

Stick with recommended tire psi in the owners manual?

Keith, if you are new to motorcycles, have you done the Motorcycle Safety Foundations course? I'm far from the USA, but some on this forum recommend it.

Raptor Petcock installed. Capped off the old vac port and put in a new fuel line b/c mine wasn't in great shape.  Filled her up with new gas and rode around for 20 miles.

I also snugged the header bolts (I think - I tightened 2 bolts)

Bike still backfired when letting off the throttle in 1st gear and sometimes in 2nd.  She ran great though.  I am going to take IslandRoad's advice and read up on carbs and tuning.  Possibly when it cools down this winter the backfire will disappear.  And the bike is running strong when ran hard.  I might be in the sweet spot!?

Tires appear to be the original IRC Grand High Speed's.  At 5 years/1,250 miles the tires aren't very worn, but I guess the rubber is aging a little.  I guess I'll get some new Shinko's at some point?  But not in a rush?

Thanks everyone for help so far.