Oil dripping from carbs

Patton wrote:

Would check for fuel intrusion into crankcase.

Good Fortune!

Thanks Patton. The oil looks OK, although I plan to take the clutch out next week so I'll get a better look at it then. The drain hole from the air box is below the breather tube from the crankcase so it seems unlikely that gas would get into the crankcase that way. It also seems like it would have to run slightly uphill to get into the cylinders from the carbs but I guess that's a possibility. I have a petcock rebuild kit so I'll probably do that and replace the float needles when I take the clutch apart. I just rebuilt the carbs, including new float valve seats and needles, in 2007 and as I mentioned above have only ridden it about 3,000 miles since them so I'm a little irritated that one or more of the float valves is leaking.

Motor Head wrote:

Sorry my bad, didn't realize the other post about the work already done.
Do you run a factory air-box or pods? If pods maybe over-oiled? If not, then you sure it's not fuel? A small fuel leak do to a float bowl gasket seep, or to high a level? There isn't to many places oil would drip from on a carb. Could it be a leak from the valve cover, then the airflow has spread it?
Just some thoughts.

No problem, Motorhead. I've got the factory airbox with a foam element. I don't want to mention when I last oiled it because I don't want anyone to think I don't love my motorcycle, but it doesn't seem too oily. I had a leak around the base of the oil pressure sending unit last summer but replaced those o-rings and that seems fixed. There doesn't seem to be any oil coming from the valve cover. I think I might reduce the fuel levels in all the carbs, although that seems like a major undertaking because it seems like you have to adjust the tangs and put the bowls back on to check how much the fuel level has changed. Anyway, the drips could be gas but they smell like oil and they're thick like oil and they feel like oil. I hope they're gas though.

I had the exact same oil leak on my 1100 after the 3rd oil change after getting it back together, just looked and said WTF. But easy to change them.
Yea its kinda trail and err to find the exact fuel level, then adjust, and repeat. Not to many carb's out there like a Holley, adjust externally!
Have you ever used any UV oil dye? There is a kit you can get real cheap these days, they have a more or less universal dye. In the old days they had about 8 different dyes for the various fluids. Takes the dye some yellow glasses, to high light, then a black light. I've seen kits for around $30 bucks.

Thanks Motorhead. I will try that if I'm still getting the oil from the bottom of the carbs after I reset the floats and replace the float needles (just in case it's really gas).

I'll add another oil leak diagnosis procedure, you might already know this, but others might find it useful.

This will work on most engines with a crankcase and a oil leak. The idea is to pressurize the crankcase with low air pressure, using compressed air, Regulated to 5psi, attach to the crankcase breather fitting, blocking all other external sources. On you bike there wouldn't be any but the breather where you now are pressurizing, but on other engines there would be a dipstick, PCV valve, etc. So with the crankcase now feed with air pressure regulated down to 5 psi, now you can see if it is a low leak, the oil coming out, or if a higher than oil level leak a spray bottle with soapy water will make bubbles at the leak just like a tire with a leak.
Remember to keep the Air pressure down to 5psi.

Motorhead,
Thanks, I hadn't heard of that technique. After I see what the clutch needs I'm going to clean it all up and see if I can see where the oil is coming from just by running it. I'll try pressurizing it if I can't see it otherwise.

Motor Head wrote:

I'll add another oil leak diagnosis procedure, you might already know this, but others might find it useful.

This will work on most engines with a crankcase and a oil leak. The idea is to pressurize the crankcase with low air pressure, using compressed air, Regulated to 5psi, attach to the crankcase breather fitting, blocking all other external sources. On you bike there wouldn't be any but the breather where you now are pressurizing, but on other engines there would be a dipstick, PCV valve, etc. So with the crankcase now feed with air pressure regulated down to 5 psi, now you can see if it is a low leak, the oil coming out, or if a higher than oil level leak a spray bottle with soapy water will make bubbles at the leak just like a tire with a leak.
Remember to keep the Air pressure down to 5psi.

Great tip!

Would suggest also adding to "Tools" category.

Thanks for posting!

Good Fortune!