Have a 1986 FLSTC, (first of the FLSTC, really an '87 model) that I did a top end job on winter of 2010 and finished around March 2011. Reason I did it was to fix base gasket oil leak on rear cylinder. Replaced all top gaskets, valve stem oil seals, re-ground valves, had cylinders honed, fitted new rings, (standard size as pistons were standard), fitted an EV27 cam and re-built the S&S Super E carb.

All went well, bike started fine and ran like a train. It appeared to use oil from day one which I put down to just having to break it in. Have been running it since with no problems at all, except, it is still using oil. It used no oil before work.............

On a run today of about 100 miles topped up with about a quarter of litre when I got home, and I always have to top up after a run. While running under load no apparent smoke, but while ticking over (idling) smoke from exhausts is fairly visible.

Question, before I pull the top end off again, is there anything else I can check that might cause oil consumption?

I did notice awhile back, have not checked recently, that looking through the carb there was a "pool" of oil sitting in the middle of the intake manifold.

If the oil breather valve was a tooth out, would that cause it to use oil?

Any ideas or suggestions to save pulling top end off appreciated.

Cheers,

TC.

 

Well,

You stated you honed the cyclinders, did you check the bore to see how worn it was. May have needed to be bored out, as opposed to honed to get a tight fit.

 

Had cylinders honed?... What size were the cylinders? ..What was the ring gap? Did you stagger the ring gaps? Are the rings on correctly?...you can put some on upside down...What is the compression?

 

Never considered a re-bore as it was not using any oil before pull down.

Didn't measure cylinders as pistons were marked as STD.

Ring gap was as per manual and staggered. I am and was aware of the fact that oil scraper ring has a right and wrong way up, but accidents can happen and perhaps.............

Compression a few months ago was up in the 170lbs per sq inch area, will check again during week.

I am aware these are all things to check as I pull it apart again, but anything to check in meantime??????

Could cam cause problems, oil breather valve, could I have screwed up fitting valve stem oil seals????????????? (I actually did not fit them myself as I had no spring compressor so left it to machine shop who may not be used to Harleys, could they have messed up?)

I did same job on a '89 Sporty a few years back with no problems.

TC

 

Just curious, what weight oil are you running?.,,

 

Maybe it wants to run lower on the stick now w/ the new rings? I'd let it go down to the bottom of the stick, see if it stabilizes.
Oil on the manifold. Too much oil?

 

Smoke at idle. Again, too much oil? Upsidedown rings?

 

Using a mineral oil.

Interesting points hagger.

Had not thought of being over full with oil. Am running it a recommended level, near top of dip stick with bike up-right.

Would it be a good idea to let it run low? Does this not mean there is not enough oil to do job properly, or is it a case that once there is a level on stick there is enough oil in tank to keep pressure up?

 

You didn't measure the jugs? They can be worn out, oval, tapered. The piston will still be marked standard even when it is all worn out. But the most likely culprit will be a knackered valve stem seal. Easy to screw them up.

 

As long as it shows on the stick your good. What color smoke are you seeing?
Mineral oil?