BURNING OIL/ Twin Cam w/ S&S 106

Did a big bore upgrade. Had the heads ported and polished. Put it all together and commenced the break-in. Used Mobil 1 as recommended by S&S. Changed oil at 50 miles, 500 miles and again at around 1100 miles. All went well, bike ran great with no apparent issues. At around 2000 miles it started burning oil at a pretty good click (black smoke on acceleration, not blue). It's only the front cylinder (nasty spark plug). I was adding a quart every few hundred miles, the bike runs fine otherwise and makes no abnormal noise except when the oil gets to low (rockers/pushrods ticking). When I did the oil changes during the break-in, I got plenty of oil out and had no signs of burning oil.

Could the rings still be bad? Valve guide seals? (Heads disassembled) I plan on doing a leak down test to see if I can figure out which. Not looking forward to ripping it apart again. Anyhow, thanks for any advice in advance.

 

Black smoke usualy indicates unburnt fuel not oil ..what does that front plug look like ? actually wet with oil? a compression test will tell quickly if the cyl pressure is different from front to back ..I have seen a fresh rebuilt norton smoke cause the ring gaps were lined up

 

As you already mentioned, a leakdown and/or a compression test will be the beginning of where the root of the problem lies.
Pull the air filter, and look into the t/body, as well as pull the pipes and have a look into the ports, for signs of oil in both areas.
Scott

 

The front plug is black, looking close to being fouled, the rear is clean/normal. There isn't any oil on it.

 

I will pull off the pipes to look in there for oil as well. Didn't notice anything out of the ordinary in the TB.

 

Do the leakdown test so you will know where the problem is. Maybe you will get lucky and R/R head will be enough.

 

I hope it isn't the ring gap or cracked rings from not being gapped right. Compression test it so you'll know where to start. Bob

 

a extreamly rich condidition cound have washed the cylinder down,causing the rings not to seat(kinda funny to have in only one cyl. though),do a leak down or pull heads to check guides

 

You said you looked through the TB, so you must be injected. Could be an injector not closing properly.

 

I had this same issue last year with a S+S bb kit. I had a terrible rap and when I tore it down we found excessive clearance between the pistons and cylinders. I ended up tearing it out.