86 harley oil leaks out carb when you start it

Sounds like you crank ventilation is obstructed

All Harleys will get a little oil in the breather.

However, when mileage causes the rings to wear, combustion pressure can leak past the rings, causing higher pressure.

You didn't state your mileage, but at 11 years old, your engine might be ready for a top end rebuild.

Have you tried asking John?
The high revs and back fire may be an air leak on inlet manifold or carb connection

Gavin
Tugun

If you have gasoline in the oil tank after sitting for two weeks, you probably have a bad petcock. In 1996, Harley went to a vacuum operated petcock. They are notorious for leaking fuel. Additionally, you have a problem in your carb. Either the needle and seat are not sealing and leaking fuel into the carb or the accelerator pump diaphragm is bad causing the fuel to seep into the engine.

Once the fuel seeps from the carb into the engine, it will get past the valves, and the rings on the piston and into the crankcase. It will sit there until the engine turns over. At that time, the oil scavenger pump will pump it into the tank.

I suggest you replace your petcock with a high quality manually operated petcock such as a Pingle, have your carb gone through by a competant mechanic, and change your engine and primary lubricants.

Good Luck
Steve

Sounds to me like it's finally time for a top end job. An '86 model with 51K on the original top end is good but it's time has come. A Harley engine is an air cooled engine and as such it will not have the longevity of the top end of a water cooled engine. With that being said, getting over 50K out of your top end does show that the bike has not been abused and has good maintenance done on it.

To make sure, you can do either a leak down test on the engine or a wet/dry compression test. This will tell you how much compression is getting past your rings. The compression getting past the rings is causing excessive crankcase pressure which in turn is causing your oil problem in your air cleaner.

I think the '86 models still had the early model head bolts rather than the nuts like the later models. This will require a slight modification of your heads and the purchase of a set of case studs and the nuts. Harley has upgraded the studs in the '96 models and they are better at preventing the leaks so common at the base of the cylinders. Have the machinist check the diameter of the cylinders to see if they need boring. If so, you'll need a new set of piston but if boring is not needed, you'll need only a new set of rings and have the glaze in your cylinder broken. A valve job on the heads may be in order since the valve guides were bad about cracking on the earlier models.

Ok, that's my opinion as to what you need to do but take it to a qualified mechanic and have him check it out as well.

Good Luck
Steve

Ok, your bike has been sitting for a while. The oil is all in the crankcase. This is a common problem with Harley's that have the tank located higher than the engine. The oil seeps past the check valve in the oil pump.

Take the spark plugs out of your engine and spin the engine with the starter. You need to be careful that you don't burn up the starter. Spin the engine for about 20-30 seconds and then let it sit for about five minutes before you do it again. Once the oil tank is back to nearly full, you can try to start the engine. Do not add any oil to the tank until you get the engine running. You must pump all the oil out of the cases first. As long as there is oil in the tank, you can safely start the engine.

But, if it's been sitting that long, you will probably have to put fresh gasoline in the tank and go thorough the carb before it's going to start. I'd take the carb off the engine and take it to a shop and have them clean (rebuild) the carb. To get the carb off, remove the air cleaner cover, filter, and backing plate. Loosen the throttle cables at the throttle grip. Loosen the large nut on the choke cable near the knob on the left side of the bike and let it swing freely. Remove the cables from the carb linkage and disconnect the fuel line. Pull the carb out of the intake manifold seal being careful not to damage the choke cable.

Installation is the reverse of what I just told you except you must be certain of the correct throttle operation prior to starting the engine. You don't want the engine starting up with the throttle wide open. Make sure it work properly.

Good Luck
steve

Without any real detail about year, filter type or where the oil actually is "in" the carb I will try to answer. Oil can come from a few sources. The first is the breather tubes from the engine. If there is excessive blow-by the pistons, oil will be drawn into the carb through these tubes. There are also rubber check valves on top of the heads that can harden and cause the same issue. The last one is excess oil from a oiled cotton style filter (K&N). Either way, while in the garage, remove the air cleaner but leave the breather tubes connected. Get the motor up to temp and watch the tubes while reving the motor. If you see a heavy oil mist from the tubes perform a leak down check on each cylinder to identify the problem area.

is it leaking from airbox or carb ??