Bike is smoking when hot.....rings?

[Doctorshred]

I bought the bike as "salvage" it was in a fire, and had burnt enough to melt most of the wiring, and the carb a little. I slapped on a new S&S super E carb, and re wired it long story short thing runs great with plenty of power.
I have been running Castrol 20/50 non synthetic oil with a couple of oz. of "Lucas Oil Stabilizer" in my crank case. I have always used Lucas in my hot rod chevy's, but I am beginning to question it in these v twins. Also are these older fxr's just prone to burning a little oil when there hot with high millage? Could the fire have damaged something internally to make it smoke like this? It runs great by the way, and is fast as hell with no backfires, or misses one so ever. I even get the back tire to break loose in second when I am hammering on the gas, so performance wise It seems fine with no lack of horsepower one so ever...
If you have any ideas please let me know.... Or if Lucas is a bad idea for an evo please let me know that as well. I hear "Amsoil" is the way to go what do you guys think.
Thanks for your time....

[Unca Mike]

Yeah Shred, old Harleys do burn a little oil as the miles pile up. Your bike might need a top end freshening which would include new valve guides, valve guide seals, and maybe rings (as well as a valve grind) all of which could be passing some oil. If you want to go that route... great. Or you could just ride it and have fun. A little oil here and there is no big deal. I think having an old huffing and puffing Harley that you got real cheap and is still delivering the big fun is pretty cool. Kinda like the "rat" bike thing. Personally I'd do the top end job.

20w50 oil is fine. I prefer Mobil 1 15w50 synthetic but with an old engine it probably doesn't matter much. Just keep fresh stuff in the bag. The "oil stabilizer" might not be necessary. I'm guessing it's something like the old STP Motor Oil Treatment. I remember people thought that stuff calmed down the oil burning by supposedly thickening up the oil and preventing it from thinning down as the oil heated up. I used it on some old car engines and it made me think it helped. Whether it did or not is open to question.

[Renegade FXRS]

By older what do you mean? I have a OLD FXR which is a 83! Yes it smoked a lil and burnt some oil...But after a fresh topend(new Valves ,Guides and seals, Rings and pistons) burnt oil during the break in first 500 miles but since then and 3500 miles later seriously have not needed to add a drop of oil!!! Nice tight motor and I ride Hard!! On its 3rd Oil Change and couldnt be happier!! I would try a fresh top end and I run straight 50weight oil!! On older motors I would run straight 50 all the time and if running hot weather 60 weight! The shop that did my work recommends straight 50 in all older bikes 99 and down and 20/50 on newer and none of that synthetic crap!! Pardon my language but we have not seen any good from synthetic!
Just My Opinion ..But what do I know......... I run Shovels! LOL!

[econnor]

We need more information. What color is the smoke? Is it coming from both pipes? Have you done a cylinder leakdown when the engine was cold and hot?

The fire may have melted the valve stem seals, that would cause and engine to smoke. And number ofrubber things in the engine could cause the engine to smoke, but no need to do a top end until you know the facts, and they will come with the leak down test.