I was looking in my Owners Manuel and it says to use a good quaility Leaded or Unleaded fuel 94 octane or better. My question is were the valves seats the correct material for using an Unleaded fuel? I had thought of doing the No lead conversion on my heads but it looks like I don't need to. The book also says 1982 and later to use 89 leaded. So 79-81 could use either leaded or unleaded but 94 octane. What do you think.....I don't need the conversion?

 

I would use the highest octane gas available, especially to avoid "death by pinging".

There seems to be two opposing opinions on the hardened seats. Some guys highly recommend having them installed, but only if the heads are already off for other work. Other guys say theirs has been running for 30 or 40 or whatever years with the original seats and no problems so why bother with the expense.

One of the problems with these kinds of opinions is separating out those who really do know, from those who are just passing on stuff "they have heard". I am in the latter category in this case.

 

I have riding with normal (highest octane) gas, with 2 ironheads ( -74 -78) without problems.
Both bikes with are/were stock valve seats, so if you are planing to do it anyway put hardened, if it's just for "sure" don't bother...
If I remember correct -79 they stop selling leaded fuel in US, so 1980 sportster should be "good" for unleaded. Some use some additives...

 

Thanks for the help. When the heads need rework then I'll get things done. I bought some lead additive that I use every so often when I remember after fill up. I guess it could be a long time before I need head work but then again that's not what my shrink said.

 

My '73 gets whatever is at the cheapest pump, runs fine. As for this stuff about hardened seats, you can either add a lead substitute or do like I do on my old classics, just run them. Never had a problem on any of them

 

When I pulled the plugs out of my parked-for-22-years XLS, I found considerable lead fouling on 'em.

Made me wish for the good ole days when I wore a younger man's clothes.