Look fellas, I should explain myself more clearly. I started out responding to the question had I used valve guide seals? Well, yes I have, and gave my results to date. BUT, I think my responses in this thread have been confusing.
First, as Sidewinder suggests, on a stock machine, every thing works fine in the intake department, and there's probably excessive wear, by modern standards at any rate, on the exhaust. And oil consumption is acceptable.
If you want to stay with the stock systems, every thing seems to balance out just fine, live with the system as designed, and live in bliss.
But, I wanted to change things on my bikes, I just couldn't leave well enough alone. I was extremely frustrated with the short lifespan of these motors. After fighting it for 35 years of wearing out a top end in 10k miles or less, it just got to me. Besides, we all know I like to tinker.
So, there's option one, leave it as the factory did it, and motor into the sunset. (As long as the sunset is less than 10,000 miles away!).
So, of course, when I start messing with things, I start running into problems. Which is what I proved when I started out with a half worn out motor, but one that was doing fine as far as leaking, oil consumption, power, etc. goes.
I changed the oil pump system, and then I had a host of other problems appear. Oil seals on the valve guides was one of the fixes to a problem I made. We'll see if that creates excessive wear problems in the future, don't know yet. I'm probably only at 3k miles on the first conversion at this point.
So, you can stay stock, enjoy the ride, and do a rebuild once and awhile. Or, totally change things around, enjoy the ride, and do less rebuilds.
One last thing. all this refers to the Big Twin 74 and 80 sidevalves. I don't know that the 45's have the same top end problems. I just haven't the knowledge.
Thanks for listening,