I am bringing a '97 FLSTC back from the grave. Just rebuilt the carb and went for a test ride. It runs perfect. However, the carb overflow drain tube puked a couple of drops of oil. What gives? Does this mean I'm burning an oil/gas mixture now? I have not pulled the plugs yet to look.

 

Are you sure it's the carb drain tube and not the case breather?

 

possibly the head breathers blowing a bit of oil into the carb? either way getting the breathers to vent out to the atmosphere would help the motor over the long haul and eliminate that as a possibility. only way I see oil getting into the carb.

 

Yes. Vent tube on bottom/side of carb bowl. Same tube that vents gas if your float sticks or is adjusted incorrectly. If I am burning a gas/oil mixture I assume the plugs will be on the black side.

 

It does if your head breather is routed to the back of your carb.
Reroute your head breather out to atmosphere and everything will be fine.

 

I understand the concept of what you said. The breather circuit goes into the air filter bracket. I'm scratching my head.....if too much oil/vapor goes into the air filter, could it then travel back into the carb as an air/oil mixture? As a test I may disconnect the breather hose at the air filter bracket and vent to ground. Is my reasoning sound?

 

Thanks. That seems to be the logical problem. Will report back when resolved.

 

and dont reconnect it once its off. its an epa type deal that just leads to garbage building up all along the intake track. grab a longer length of tubing and just run it to the bottom of your bike. it will drip a bit but…...

 

Yes and yes.

 

Thanks guys. Bought a length of 3/8 hose and vented to ground. After 100 miles I have no trace of oil anywhere on the engine. This explains why the bike was so damn dirty when I bought it. OH yeah, plugs look perfect too.