is it possibleforfor there to be gas smell in the oil? Not a strong smell but it is there.I have a 84 ironhead custom sportster. This bike i just got. i have a 98 superglide and never heard of this problem. Your help is needed Thanks Charly

 

sure. if the bike is setup to run on the rich side, and your rings allow blowby, you could be getting some of what is supposed to be burned in your crankcase. another cause could be if when parked, your float in the carb is set high, and raw gas is dribbling into the cylinder past the rings into the crankcase. I'm no expert but I did stay at a holiday inn express last nite.,,,,,,,,

 

Very common on carb bikes, wuth overflow gas leaking through cylinders into oil. Needle and seats in carb may be bad, but turning fuel valve to off anytime not running will usually stop problem. Be sure to change oil soon.

 

I have a s&s carb. Does the oil change color Also can the bike get flooded and eventually get blow by. the bike seems to run good. Is there any other test I can do I don't know much about the S&s carb Thanks again charly

 

If you can smell fuel in the oil that is way too much and the bike should not be run with that oil in it at all. Look at the carb float valve and fuel shut off valve to be sure both are operable. That would be an awful lot of blow by to leave fuel smell but could be possible if the rings are very worn but I doubt it. Fuel will usually darken oil very quickly and dilute it's viscosity. But it will toast your lower end bearings quickly. Normally you would do a used oil analysis to detect blowby but if you can smell it don't bother. I would say if you replace the needle & seats in the carb and get a new shutoff valve you will probably solve the issue. Don't dothe carb first. (changed my mind on this one).

 

Now the needle in the S&S carb is under the diaghram. Now the seats are located where in the carb Thanks

 

Is there anything visually that I can see when I take the air cleaner off on the S&S

 

No you have to pull the carb off and open it up. Might as well rebuild it forthe trouble. You might try changing the oil & filter and everytime youshut offtheengine religiously shut the fuel shut off valve to see if this repeats before you dig into the carb. If you do this add 2-3 oz of carb cleaner to a full tank of gas and run it out. You may just have a dirty valve that is sticking and could get lucky. OR your fuel shut off valve may be leaking fuel into the engine while the bike sits there. I might give that a try first.

 

Don't know about Harley Engines but I used to work on Radial Air Cooled Engines in the Military. When it was real cold we used to dilute the oil with gasoline to thin it out so we could get the engines started after the aircraft set over night. When the oil got hot the gas evaporated and passed out through the breathers. We used a W120 oil which was a 60 weight. We actually had a valve we could open that would introduce avgas into the oil. The amount of gas we introduced was based on the outside air temp. We did this with the engine running prior to shutdown for the night. The system was on all the big radial engines and was called OIL DILUTION.

Again, I don't know about Harley engines. They are different from any other reciprocating air cooled engine in the world. So I have been told. (smile)

 

It could be many of these ideas, but I would bet on the rings because of the age of the bike. If the rings are worn then on the compression stroke a little fuel would be forced past the rings into the crankcase.