Motorcycle Repair: When do I do an engine rebuild?, bike owners, burning oil

Question
Hello. I own a 1987 used fxst softail with 20,000 miles on it. I am the 3rd owner. She runs decent. I see all over the net bike owners claiming they did engine rebuilds. Am I do for a rebuild? She isn't leaking but if you get really close enough to the motor an catch a smell it does smell like burning oil. I figure because its an older bike it doesnt run as clean as a newer one. She seems strong on the road. Also what do average rebuilds cost and what exactly are they rebuilding? Thanks.

Answer
First at 20,000 miles you are probably not due for a complete rebuild.
There are two different rebuilds. A top end rebuild and a total motor rebuild.
The top end rebuild consists if removing the heads, cylinders and pistons. The heads are taken apart and the valves ground and the valve guides replaced. the pistons are replaced as well as the rings and of course new gaskets. This is usually done when the bike starts to smoke and the smoke if from oil burning. If you are not smoking, need not worry about doing it then.
The total rebuild consists of the above plus doing the bottom end. The bearings are replaced as well as all gaskets.
Dont worry about the smell. Remember a harley motor runs hotter due to the fact it is not water cooled.
I cant give you a average cost. Prices are different all around the country. I can however tell you what I charge. A top end cost around 800.00. A total motor rebuild costs around 1800.00. I rebuild and ship all over the country for guys who can install their own motor.
Good luck and happy riding
Mike