Motorcycle Repair: Honda Shadow 1100, combustion chambers, head gasket

Question
I bought an 85 Honda Shadow VT1100C, the head had been broken putting on new exhaust (overtightened)and it had sat in a barn for about 5 years. I acquired a used motor, swapped the heads... after finishing putting the bike together and then spending a week with the wiring getting it to spark, I got it running, runs great, drives perfect.. but it smokes after about 150 miles on a oil change, when it gets hot, when its cold it doesnt so much..  And the rear plugs(2 per cyl) gets burnt.  This is the head I changed, my question is how do I check to see if its the rings or the valve guides or teh head gasket?  Can I do it with a compression test?  I hate to admit I skimped on the head gasket and reused the better of the two when I put it back together because I wasnt sure it was going to run at all ever.  Would the head gasket cause the oil to be burnt/thin after just a hundred miles? Thank you for any suggestions you might give me.. my email is RealFloopyGuy@AOL.com

Dave

Answer
Hi David,

Re-using gaskets may cause sealing and clearance problems. Now that the engine runs, consider replacing the gaskets.

There may be multiple problems to correct. Carburetors, gaskets, valve clerances, head torque, and other. I doubt the gaskets are the cause of the smoking. I suspect worn valve guide seals, worn valves/seats, rings/cylinders.

Perform a cylinder compression check and follow with a leak-down test. Theses tests will determine the sealing properties of the combustion chambers (condition of the engine).

I'll send tech intel on both to your email.

Respectfully,
Mark Shively