Motorcycle Repair: oil line routing, vent line, tank fitting

Question

Oil Lines   QUESTION: How are the oil lines routed on a 1975 XLCH Harley Davidson  Sportster 1000?

ANSWER: Hi, I've figured out how to get the image back on my computer on your XLCH oil system. I have a 1965 XLCH myself. But it has all 3 fittings on the bottom of its oil tank. I've been on ebay trying to get a good picture of the top front side of a 75 oil tank. But not having much luck, so I'm going to ask you to look at a few things on your tank when your reinstalling your oil lines. First is one of those fitting on the front side of your tank smaller than the other. One 5/16's and the other 3/8's. If this is the case the 5/16's fitting is your vent and the 3/8's fitting is your oil return fitting. If their both 3/8's than can you see through the fill hole to see if they end at the tank wall. If the second is true than either fitting will work as vent or return. So here we go on the routing. Bottom tank fitting goes to the oil pump suction,the pump suction is located on the rear of the oil pump under the motor on the cam side of the bike. The return line starts behind the rear cylinder at the fitting on the top of the transmission area, then goes to the center fitting on your oil filter the hose then goes from the other oil filter fitting to the inlet of your oil cooler, if your cooler does not have a thermostat valve the fittings are universal if it does have the thermostat valve then the hose routes through the valve first, but I don't see the valve in your image so route the hose from the oil filter to one fitting on the cooler and route the other fitting back to the 3/8 fitting on the top front side of your oil tank. Now route a hose from the fitting at the rear of your cam cover to the smaller or other  fitting on your oil tank, this is your vent line. The breather on the front end of your cam cover should have a tube on it that directs the pressure down under the bike by the front of your oil pumps pressure switch area. The generator should have a large washer on it in front of the drive gear to help control the amount of pressure that is dumped down the breather pipe.I hope I've been helpful and answered your questions. Sportstertodd.

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Oil Lines   QUESTION: Thanks, this does help me, but I still have a problem...I don't know what goes to the two fittings on top of the transmission (circled in drawing & photo).
I have attached my original, but updated image showing how I followed your instructions. I've also pasted actual photos of the bike with reference markings. This was the only way I could send it to you, as I could only upload one image.
Ken


Answer
Ken, After seeing the photos you sent it appears to me that someone has put 2 fittings in the holes that are for 2 3/8 by 16 threaded bolts that hold down the bracket that supports the battery box on one side and the oil tank on the other if your bike had electric start. Thats what it looks like to me unless someone made some modifications to your bike that you didn't know about, those 2 fittings are not stock. They won't hurt anything and they will allow your transmission to vent. Pull the fittings out I bet you can see the gear teeth in your transmission through the holes. The threads are probably messed up, If you could put the correct bolts back do it otherwise put the fittings back in and attach a hose to one fitting and run down between the swing arm and the motor to act as a transmission vent and plug the other fitting off. If your going to try the bolts ensure there not to long as they will engage the teeth on your mainshaft gearing and lock up the motor. Your just looking to plug the holes probably need 2 bolts about 1/2 inch long. Also when your purchasing your hose for the oil system make sure its for oil.