Leaded gas a must?

[CaptonZap]

Maybe some of you gurus can answer a question. I have an '80G XS, with 29,000 miles on it. I bought it from the original owner, and found a bottle of lead substitue in the fairing compartment. I measured vlave clearance, and got .0095 on #1 ex, and .0075 on the other three. #1 was running about right, according to the color of the plug, and the other three were white/lean.
That, to me, looks like valve recession on #'s 2,3,4, or cam wear on #1.
Do you guys recommend useing lead substitue in the gas?
I will be getting a parts bike, same model, about the same milage, and will check clearances to see what it has. The original owner of the parts bike died a few years ago, and his nephew doesn't know the maintenance history on it, so I don't know if it ran leaded gas or used a substitute. (It's been parked since the mid '80s, and I can't remember when they quit selling leaded gas).
Anyway, any thoughts on the subject are welcome. CZ

[Ken Talbot]

Short answer - no need for leaded gas.

Longer answer - there's been lots of talk here over the years about leaded gas. Use that phrase in the search tool at the top of the page and you'll find lots of discussion.

Welcome to the forum

[crazy steve]

Leaded gas was pretty much long gone by the time the XS11 came out, so no, leaded gas isn't needed or actually desired. The bikes were designed to use unleaded...

'78E original owner

[tadtl1]

no lead hx

Hi,

I know that unleaded came out in mid 74 for the 75 model cars which had the catcon. I think that leaded was phased out completely by 81 but could be off by a year or so. The 11 was built to use no lead gas without question, but I cant be sure if reg or mid octane is what it requires. I believe regular worked fine in my 79, but now with the MNS I use midgrade but have never heard any knocking at all. Wish I could say that with my other bike.

[crazy steve]

Unleaded gas first came out in late '71, as GM converted their entire '72 car line (and 1/2T trucks) to be 'unleaded capable', although you didn't have to run unleaded in the early models (the older gearheads may remember that GMs 'performance' engines all took a big hit in compression ratio and HP in '72; this is why). Ford and Chysler were later to the party, with a more gradual phase-in. By '75, most cars had to run unleaded and had been fitted with the 'unleaded only' tank fillers. Leaded fuel was completely gone by '86.

As a side note, that's where the 'F-150' Ford truck came from; prior to that it was a F-100, but trucks of 5/8 ton capacity or more weren't required to use unleaded, so Ford came out with the F-150. Chevy called theirs the 'Heavy Half'.

The main reason I remember is because SoCal (now Chevron) discontinued their 'white pump' Custom Supreme to make room for the unleaded and I had to detune my 'hot-rodded' car to run on the 'ordinary' premium...

'78E original owner

[mstic2000]

You can still find leaded gas at the pump here in Michigan at some stations mainly for boats. A mechanic that's worked on jap bikes for the last 25 yrs told me not to run higher octane in these older bikes because it will ruin them. He told me just to get the regular unleaded. Don't know how true it is but that's all I run in mine is the regular unleaded.