Excessive oil consumption at high RPM

vagabond

XS650 Enthusiast
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There are numerous other threads on excessive oil consumption and there is a lot to be learned from them. I am still new to motorcycle maintenance and am wondering if anyone would be kind enough to help me break down where to start with an oil leak.

The '79 Special II has been running very well in its first full hard month on the road after storage and restoration, so it's got some cobwebs. I've noticed, however, that it has suddenly been powering through a lot of oil, about a quart per 120-130 miles, and spraying a bit off the right side. There is clearly a leak under the crankcase from the vicinity of behind the top forward hex key and thereabouts. It hardly leaks at all when stationary and off, but over the course of 10-15 miles at high RPM on the highway, for example, it's enough to notice on my right shoe, pant leg, and the vicinity of the side panel. In fact, pretty much everything on the right side glistens moderately after a high-speed ride, and of course after 120-130 miles I need to add another quart of 20W/50 to keep the bike from overheating, which it's done twice this week because of excessive oil consumption.

I am wondering if replacing the crankcase gasket might be enough? Should I try to retorque the engine? This is my only transportation, so I'm hoping I can avoid breaking down the engine and losing my wheels for the time it takes my amateur mechanical hands to figure it all out.

I would very much appreciate any advice anyone has to offer! Thanks!
 
Can you show us a picture where the oil is leaking?

A leaking head gasket will go through a lot of oil..............draws oil from the camchain tunnel into the cylinders...............that will show up as black smoke from the exhaust (just ask me how I know:)).
 
If I'm thinking of the correct area, your tach drive is there too. That can leak as well. There's an o-ring and little oil seal in the assembly that may need replacing.
 
Yes, if running without a tach, it's best to leave all the tach drive components in place and just cap the threaded part where the cable used to connect with that little blank-off cap that Mike's sells.
 
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