fuel octane

[mjpxs11sh]

hey all. i just happened to come across the side cover sticker on my 81SH, and it says "Regular (Leaded ) 91 Octane Min". ive been using Reg unleaded 87 Octane without any issues except probably mpg, but havent ckd as of yet.

[wa407mpp]

Because of the design of the combustion chambers and the ignition advance system these bikes will burn just about any grade without a problem. In fact I could not tell a difference between regular and the better stuff.

[mjpxs11sh]

?

does anybody know whats supposed to be under the spring loaded clipped inside cover? mine's empty.

[geobiker]

Leaded?

I am a little more suprised that it says leaded gasoline, as the U.S. was switching over to unleaded by the early 80's, so you think that the placard would say unleaded (or both).

I have read that there are diffent ratings for octane so I wouldn't worry too much that it says 90.

I have run mine on 87 and 89 octane and not seen much of a difference. For the small cost difference, I run 89 octane for "peace-of-mind".

[cywelchjr]

The octane numbers back then were different then they are now. Regular is still basically the same now really as far as anti knock as it was back then, but they use a different formula that comes up with different numbers. If you look on the pumps, the octane shown on the pumps is a combination of research octane and pump octane, that sticker is based on research octane which is higher, pump octane is lower and they average the two for the number shown on the pump.

[geobiker]

Clip

I use the clip to hold my insurance card and registration card . . . I don't know if that is what it was designed for!?

[XJkid]

What about leaded vs. unleaded? Should I be putting in a "lead substitute" to protect my valves?

[bikerphil]

does anybody know whats supposed to be under the spring loaded clipped inside cover? mine's empty.

Pretty sure it was for the special cable used to compress the shocks for changing the rear tire. Then you could remove the axle without it interfering with the exhaust. It works great for document storage and a few Xtra bucks for emergency gas.

[Rasputin]

Pretty sure it was for the special cable used to compress the shocks for changing the rear tire. Then you could remove the axle without it interfering with the exhaust. It works great for document storage and a few Xtra bucks for emergency gas.

That would be good in theory but my 79SF and others also have it which did not require the use of the cable. Myself I use it for document storage. I use a resealable bag as well so no unwanted water gets to them though.

[mjpxs11sh]

?

i would have thought the compartment was there for something.
the fuel i guess doesnt matter, we're stuck with ethanol that doesnt burn as well, but like i noted, my bike doesnt seem to care what it runs on, it just runs. i dont remember the manual specifying anything in the compartment. ins card and registration sounds like a good use. thanks all

[ViperRon]

original owner

When I got my bike !980 G the cable for tire change was in the compartment and that is where I keep it. The wrench for use putting the cable on was in the tool pouch and as tight as the pouch is it would have never fit in there.

[crazy steve]

My '78 came with the tire cable in the tool pouch with the rest of the tools; it's a very tight squeeze, but it does fit....

[ViperRon]

better man

Steve you are a better man than me I just can't get it in I have tried .

[ddragon63]

I've ALWAYS ran super in ALL my bikes... I like to error on the side furthest away from detonation....

As for lead substitute they really don't make anything that actually really "substitutes" leaded gas, unless you wanna run leaded race fuel. A little marvels Mystery Oil or such in the tank every now and then will help buffer the valve to head impact. I squirt a little Lucas Fuel System treatment in the tank of the XS every other tank. I buy it by the quart for my diesel. Its got a chemical in in that works as an upper cylinder lube. I like to pretend its lubing my valves I don't know that it actually is I just like to hope

[jetmechmarty]

hey all. i just happened to come across the side cover sticker on my 81SH, and it says "Regular (Leaded ) 91 Octane Min". ive been using Reg unleaded 87 Octane without any issues except probably mpg, but havent ckd as of yet.

That decal says "RESEARCH" octane. That is the least severe method to rate gasoline. The most severe rating is "MOTOR" octane. If you look at the pump, you may find "R+M/2". 87 at R+M/2 is probably at or more than 91 RESEARCH octane.