Fuel, Ethanol, Octane. Help!

[harmonyhenry]

So, recently i purchased my first motorcycle ever! (1980 R65)
I've been doing a bit of riding on it but I'm running low on fuel and will have to fill up soon.
The guy that I bought my motorcycle from told me that he put only 87 octane ethanol free gas.
But the label on the bike recommends 91 octane. It's running just fine right now but will it damage
the bike at all if i continue to use a lower octane rating that is ethanol free or should I look for a higher
grade gasoline? I'd probably use 93 as that is what seems to be available to me where I live.

 

[dieselyoda]

Where you live may help with opinions on your original post.

 

[DonTom]

So, recently i purchased my first motorcycle ever! (1980 R65)
I've been doing a bit of riding on it but I'm running low on fuel and will have to fill up soon.
The guy that I bought my motorcycle from told me that he put only 87 octane ethanol free gas.
But the label on the bike recommends 91 octane. It's running just fine right now but will it damage
the bike at all if i continue to use a lower octane rating that is ethanol free or should I look for a higher
grade gasoline? I'd probably use 93 as that is what seems to be available to me where I live.

There is a lot to consider, such as your elevation, temperature and how you ride.

Many use an octane rating below what is recommended. But don't climb up a steep hill at WOT from a dead stop in Death Valley in summer when it is 115°F, without having the highest octane available, espcally if you hear any ping, knock or other weird noises coming from the engine.

The basic rule is if you hear no pings or knocks, and your engine shuts down instantly when you turn off the ignition, your octane is high enough.

Higher octane simply explodes at a higher temperature to prevent fuel from exploding before the spark plug fires it. If you're not having such an issue with pings and such, there is no reason to be concerned.

The opposite can be true too. You can have a vehicle that is designed for 87 but under some conditions might need a higher octane.

If octane is too low and you do have symptoms of pinging, it is best to keep the RPMs up higher than usual. Lower RPM's is where the higher octane is needed the most.

IOW, higher octane is mainly needed at low elevations, with hot engines at low RPMs.

BTW, more modern EFI engines have ways to help compensate for changing conditions as well as different octanes, to some degree.

-Don- SSF, CA

 

[DonTom]

Where you live may help with opinions on your original post.

More important is where you ride, not where you live!

-Don- SSF, CA

 

[DonTom]

So, recently i purchased my first motorcycle ever! (1980 R65) I've been doing a bit of riding on it but I'm running low on fuel and will have to fill up soon. The guy that I bought my motorcycle from told me that he put only 87 octane ethanol free gas.
But the label on the bike recommends 91 octane. It's running just fine right now but will it damage the bike at all if i continue to use a lower octane rating that is ethanol free or should I look for a higher grade gasoline? I'd probably use 93 as that is what seems to be available to me where I live.

If you ride here in CA, you won't be able to get any ethanol free fuel. But I don't find it to be that big of a deal and I am stuck with it a lot.

Weather has a lot to do with using it, however, just as with octane, but for much different reasons.

For some interesting facts about ethanol, see here.

-Don- SSF, CA

 

[20774]

Henry is a new member...his new member post says he's from Mississippi. The R65 appears to have 9.2:1 compression ratio. That would seem to require higher octane than the lowest grade. If it were me, as a minimum, I'd run the middle grade and then pay attention to the way the engine ran...listen for any unusual sounds that would indicate pinging.

 

[WalterK75]

Maybe this will help you.
http://www.buyrealgas.com/
http://pure-gas.org/

 

[Omega Man]

So, recently i purchased my first motorcycle ever! (1980 R65)
I've been doing a bit of riding on it but I'm running low on fuel and will have to fill up soon.
The guy that I bought my motorcycle from told me that he put only 87 octane ethanol free gas.
But the label on the bike recommends 91 octane. It's running just fine right now but will it damage
the bike at all if i continue to use a lower octane rating that is ethanol free or should I look for a higher
grade gasoline? I'd probably use 93 as that is what seems to be available to me where I live.

Welcome to the forum Henry!
It may be your first motorcycle but asking a question like this, with the thought that went into it means your off to a great start

Henry is a new member...his new member post says he's from Mississippi. The R65 appears to have 9.2:1 compression ratio. That would seem to require higher octane than the lowest grade. If it were me, as a minimum, I'd run the middle grade and then pay attention to the way the engine ran...listen for any unusual sounds that would indicate pinging.

Kurt has some good info to get you going.
Gary

 

[rangerreece]

Of course I don't think it would hurt the bike to run 87, 89, or 93 with or without ethanol (up to 10% that is). I would run a tank of each and carefully evaluate engine performance and fuel economy. I do highly recommend the pure gas app if you go ethanol free.

If you really wanted to go scientific, create a method (like possibly getting someone to secretly label your jerry cans) so that when you run and evaluate a tank of each type of gas, there will be no placebo effect.

And then of course, post your findings here on the forums with cool graphics, bells and whistles for all to enjoy.

Oh, by the way, welcome from your neighbor in Alabama.

(As I recall, there was a gas station in laurel MS that had a smorgasbord of gasoline flavors per pump, 87,89,91,93 with and without ethanol. If you go scientific on us and accept my challenge, one other variable you might want to consider is having your cohort buy all the gas from one station if possible. There may be differences in gas quality from one station to the next; just a quick thought)

 

[harmonyhenry]

Wow. thanks for all the great replies! Elevation and temperature factors give me a lot more to think about than just me thinking about the type of gas I put in.

Of course I don't think it would hurt the bike to run 87, 89, or 93 with or without ethanol (up to 10% that is). I would run a tank of each and carefully evaluate engine performance and fuel economy. I do highly recommend the pure gas app if you go ethanol free.

If you really wanted to go scientific, create a method (like possibly getting someone to secretly label your jerry cans) so that when you run and evaluate a tank of each type of gas, there will be no placebo effect.

And then of course, post your findings here on the forums with cool graphics, bells and whistles for all to enjoy.

Oh, by the way, welcome from your neighbor in Alabama.

(As I recall, there was a gas station in laurel MS that had a smorgasbord of gasoline flavors per pump, 87,89,91,93 with and without ethanol. If you go scientific on us and accept my challenge, one other variable you might want to consider is having your cohort buy all the gas from one station if possible. There may be differences in gas quality from one station to the next; just a quick thought)

Hey, neighbor! That sounds like a pretty good idea to do. I might just have to try that out one of these days. I'll most definitely post it here.

You don't think it'll cause any damage at all? Like I said I am brand new into motorcycles so I'm starting at square one. Not sure if that is a dumb question or not.

 

[rangerreece]

Wow. thanks for all the great replies! Elevation and temperature factors give me a lot more to think about than just me thinking about the type of gas I put in.



Hey, neighbor! That sounds like a pretty good idea to do. I might just have to try that out one of these days. I'll most definitely post it here.

You don't think it'll cause any damage at all? Like I said I am brand new into motorcycles so I'm starting at square one. Not sure if that is a dumb question or not.

No, there have been numerous discussions on ethanol in gas on the forums, and from these discussions I can say with confidence that running a tank of ethanol in your tank will not hurt the bike. You have a low compression engine compared to modern bikes, so the high octane may not give you the performance value that a high compression engine will. If your bike doesn't have a catalytic converter, you could ride to your local airfield and put 100LL (low lead) in the tank without hurting it, but again, low compression, no benifit. I've even run 93 octane in my lawn mower. No problem. If you ran ethanol in your bike and let it sit all winter, yeah, you'd have a problem. Running a tank of each won't hurt. I've ran 87,89,91,93 ethanol and no ethanol in my bike '05 RT ran octane booter, etc... My engine runs great, no damage, just get the best performance from 93 test no ethanol (that may be my placebo talking). I equate performance/efficiency with long term sustainability.

 

[36654]

This may be of some help.

http://bmwmotorcycletech.info/valves.htm

Also, do some research on your carburetors and the routine repairs.

But, most of all, enjoy yourself and the bike.

 

[arbolmano]

Olden Days

By all means, follow the prior posters link to Snowbum's site. On modern bikes with digital fuel management your pretty
safe with fuel. Not so much with Airheads. Those were designed back in the days of leaded fuel without alcohol. Snowbum know's
his stuff.

 

[GeorgeR1200RT]

Ethanol free fuel is also available in many marinas as boat fuel....it is also expensive.

I suggest you check the carb floats. The early ones would get heavy and sink if used with ethanol.

I replaced the floats on my 1971, 1982 and 1984 airheads...usually when the carbs started to overflow at inconvenient times.

Enjoy your R65.

 

[DonTom]

Henry is a new member...his new member post says he's from Mississippi. The R65 appears to have 9.2:1 compression ratio. That would seem to require higher octane than the lowest grade. If it were me, as a minimum, I'd run the middle grade and then pay attention to the way the engine ran...listen for any unusual sounds that would indicate pinging.

There are a lot of exceptions to compression versus octane. For an example, my 1984 Yamaha Venture has a 10.5:1 compression ratio. Even the owner's manual says to use 87 octane (usually the lowest grade). But it does fine with 85 octane-(the lowest octane I have ever seen anywhere)-even at sea level with a warm engine. But it is water cooled, unlike these airheads.

However, I agree one's own ears is really the best test.

That is if it doesn't run-on when the ignition is turned off when the engine is well warmed up, which is also a good sign of too low of an octane.

-Don- SSF, CA

 

[dennisdarrow]

So very true about the modern era bike's needs versus those of the older design. MANY MANY rubber parts in the carbs of the older models, yours included, which will surely deteriorate with the use of ethanol. MOST small engines manufacturers, of which the air cooled BMW engines are actually, advise NOT to use ethanol for this very reason.
As an aside, Husquavarna sells their own treated fuel, at like $7 per quart. Lead free and 95 octane. As is pointed out above, your engine has a high enough compression ratio, of the older design engine, to warrant use of a higher octane............Try the lower stuff, if you get "pinging" go higher.............It really is that simple. For me though, I suggest NO EHTHANOL.........God bless......Dennis

 

[snowbum1]

I suggest extra caution on the R65 model, regarding jetting, fuel, ignition timing. I also suggest sorting it out a bit at a time, keeping in mind that the R65 does NOT LIKE WOT at lower rpm. I've have seen a couple of them blow up. I am no kidding. DO NOT LUG THESE MODELS.
Running an R65 on 91 octane all the time is not a bad idea, nor is running the mixture a BIT richer, for added valve cooling.
snowbum

 

[harmonyhenry]

so,,

So i've been MIA for a while now. The selector rod on my bike broke so I've been waiting on that for a while.
But before I that i ran out of gas and decided to put in 93 grade gas. I dont know if it's just my head but i would
say there is definitely an improvement in the quality of my ride! I will see about trying the other gas ethanol free
and such!

 

[dieselyoda]

Fuel, buyer beware.

I suggest extra caution on the R65 model, regarding jetting, fuel, ignition timing. I also suggest sorting it out a bit at a time, keeping in mind that the R65 does NOT LIKE WOT at lower rpm. I've have seen a couple of them blow up. I am no kidding. DO NOT LUG THESE MODELS.
Running an R65 on 91 octane all the time is not a bad idea, nor is running the mixture a BIT richer, for added valve cooling.
snowbum

I guess experiences vary. I had a friend with an R65 and he rode it like he stole it and never really had any issues.

One thing though, a few years ago we were in NW-Ontario and running low on fuel. We had a choice between an FN Gas Bar and a chain owned Gas Bar and went with the chain. They only offered one fuel for gasoline and the Ethanol content wasn't posted. He didn't make it back to Winnipeg without fuel pouring out on his boots and I kept looking at my RID bouncing to the Red Zone. No leaks for me and good fuel solved my problem but his Bings' needed all of everything and then some.

The rubber in his Bings' looked like well used condoms and that is a polite way of stating that they were sticky and wet. The rubber came off in my hands and the diaphragms were super thin and could be used as, well, condoms.

 

[royce]

Not trying to complicate this thread (it's complicated enough as is), but I find in my personal case that the presence of ethanol in the fuel definitely lowers my fuel mileage. Over the lifetime (3 yrs and about 20K miles) of my current bike. I have kept detailed records of my fuel usage in a logbook at every refueling. The ST gets 3-5 MORE miles per gallon when I use ethanol-free fuel as opposed to using fuel with ethanol. And it doesn't make any difference what the octane number of the fuel is. The improved mileage numbers are present for ALL octane levels from 85 (in my mountain riding) to 93 octane and everything in between. I understand that modern bikes like mine are able to use ethanol fuel with no damage, but I prefer ethanol-free for the mileage benefit.