Something to consider is ethanol characteristics is like 115 equivalent octane. Now or in the future higher octane gas may be created by blending with higher percentage of ethanol. Or this all could all be a simulation...
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Type of gas to use for 1974 XS650
- Thread starter Jakethesnake1994
- Start date
Ethanol may act like a detonation inhibitor but would require quite a high volume to be effective. The stoichometric ratio of oxygen to gasoline is the well known ~14.2:1. The ethanol oxygen to ethanol ratio is closer to ~7.5:1. Remember that if you chose an ethanol fuel you would need carburetor jets that flow 2 times more fuel.
E85 vehicle must differentiate. O2 sensors adjust the mix on gas to 15% ethanol gas I would suspect.
I buy the 93 or 94 here in BC because of the lack of ethanol. I do run the less expensive 87 octane fuel with Ethanol in my DR650 but I'm generally going through 1.5 tanks per week. I do run a few tanks of the 93 or 94 through the DR and leave the tank full when I'm planning to park it for a few months.
I "suspect" it does nothing different
I would run on 87 and hear a fair amount of pinging under certain conditions, like going up a mountain or hard acceleration. W/ 93,94 I would hear less but still hear it. I adjusted my base timing of my TCI to just inside the minimum and have used 87 ever since with no pinging and no problems. Added benefit is it gives a throatier sound. If there is no pinging there is no problem. Too retarded can overheat, so shoot for only the minimum spec. You could probably do the same on a '74 if you have something indicating the minimum base timing. I have tens of thousands of miles w/ that timing and 87 octane and no problems
Not an expert but on automobiles there has been sensors for a long time
Modern engines has a lot of sensors that can adjust fueling and ignition ---timing.
fex
The engine’s knock sensor (or sensors) detects preignition and detonation, potentially damaging forms of abnormal combustion. Though full-blown knocking and pinging are audible to the human ear, the knock sensor detects imperceptible levels. When knocking is detected, the engine’s computer can retard the spark plug timing to prevent it. In the event of knock sensor failure, the driver may experience audible knocking or pinging and/or diminished acceleration, which is sometimes accompanied by decreased gas mileage. A check engine light is a likely result.
But perhaps the biggest concern is how ethanol affects carburetors and gaskets and hoses ..Especially if left in the machine for a while that many owners are likely to do if not most owners.
Needing to clean carburetors on a regular basis
If I can I will not use any fuel with ethanol and I try to keep carbs and tank empty over winter
Machine was designed for ethanol free fuel and that is the norm / goal
Perhaps it can work with other fuels but i am not taking the risk if I can avoid it ...
Modern engines has a lot of sensors that can adjust fueling and ignition ---timing.
fex
The engine’s knock sensor (or sensors) detects preignition and detonation, potentially damaging forms of abnormal combustion. Though full-blown knocking and pinging are audible to the human ear, the knock sensor detects imperceptible levels. When knocking is detected, the engine’s computer can retard the spark plug timing to prevent it. In the event of knock sensor failure, the driver may experience audible knocking or pinging and/or diminished acceleration, which is sometimes accompanied by decreased gas mileage. A check engine light is a likely result.
But perhaps the biggest concern is how ethanol affects carburetors and gaskets and hoses ..Especially if left in the machine for a while that many owners are likely to do if not most owners.
Needing to clean carburetors on a regular basis
If I can I will not use any fuel with ethanol and I try to keep carbs and tank empty over winter
Machine was designed for ethanol free fuel and that is the norm / goal
Perhaps it can work with other fuels but i am not taking the risk if I can avoid it ...
Do E85 vehicles have 2 sets of injectors? The system needs to deliver near double the fuel of a just pure has mix.. Vehicles with gas or E10 gas have feedback loops including the O2 sensor to deliver a proper ratio. I get ~5% better mpg on pure gas in my recent autos.I "suspect" it does nothing different
I'm good with that, as long as it's not a suspicion. At first glance it feels like it would be hard to do anything but shoot for a compromise, something not ideal for either component by itself
E10 has approximately 5% lower btu/liter and it seems standard injector systems can deal with that 5% variance adequately. But when you peruse high performance engine builds of Chevy, Ford or Mopar motors one upgrade is often "High Performance" injectors to deal with higher fuel delivery requirements. Perhaps the E85 engines have injectors that deliver an adequate spray pattern over a range of flow rates that vary 100%.
hovel
ol' stupid
That would be especially true if you chose to use pure alcohol, which would most likely be methanol, in a racing environment. Motorcycle racers have told me that not only the jets, but the entire supply system has to be up-sized. Years back we asked a drag racer, Jerry Gwynn, about jetting for methanol. He said he increased the size of the jets until the plugs looked wet, then he backed off a step. It is my understanding that reading plugs in an alcohol engine is a whole other ball game.
Again no expert .so apologize if wrong
I believe the injection and timing is handled by the modern electronics and the 3 -4 -5 - ? sensors
If I recall right it was called common rail system. There can be more modern ones.
I believe I have that on my Honda Fireblade
Upon turning the key a pressure is added on the fuel system and injectors
It takes a couple of seconds.
Then at running the electronics opens and closes the injector according to rules Of the program and sensors
When and how long time they are open. This can be cylinder specific.If sensors are there for it.
The injectors have different sizes and are replaced. With the same size on all cylinders
By car tuners when they tune for more power .
The rule seems to be not taking to small when replacing
So the solution I believe ( Pure speculation ) is that for cars that can use different fuels
As long as the program and sensor can read the parameters and the injector is large enough
The point and amount of the injector squirt is nothing the owner needs to be messing with
The Madam Lawyer who can be Environmental friendly and buying a low emission vehicle.
Dont want to read the fine print or scratch their head at the Gas station ..Of what to pour in
Which sometimes goes wrong Mainly diesel into Petrol engines or vice versa When hauling it to a shop for action is needed.
So to sum it up again apologize if it is of topic and plain wrong
The electronics is much better in emission control and engine government than an old carburetor.
As long as the electronic is working it can handle the fuel which can contain water and ethanol at unknown concentrations which a XS 650 is not as good at
The electronic itself is something people swear at. The small red lamp at the dash board that the inspector at the MOT station detects that can lead to expensive repairs
At the brand dealer and special filters ( Catalysator ) that is so expensive that scrapping is the only solution.
As a side note the Fireblade has variable intake and Exhaust length if i recall right at 8000 rpm flaps are turned and
other flow paths are used for the upper revs .
Would suspect with different injector times.
I remember reading of the drag racers having the challenge of reprogramming these Chips and black boxes for achieving their goals whereas carburetors is different
Those black boxes have secrets not easily accessible jfr Volkswagen fraud.
I believe the injection and timing is handled by the modern electronics and the 3 -4 -5 - ? sensors
If I recall right it was called common rail system. There can be more modern ones.
I believe I have that on my Honda Fireblade
Upon turning the key a pressure is added on the fuel system and injectors
It takes a couple of seconds.
Then at running the electronics opens and closes the injector according to rules Of the program and sensors
When and how long time they are open. This can be cylinder specific.If sensors are there for it.
The injectors have different sizes and are replaced. With the same size on all cylinders
By car tuners when they tune for more power .
The rule seems to be not taking to small when replacing
So the solution I believe ( Pure speculation ) is that for cars that can use different fuels
As long as the program and sensor can read the parameters and the injector is large enough
The point and amount of the injector squirt is nothing the owner needs to be messing with
The Madam Lawyer who can be Environmental friendly and buying a low emission vehicle.
Dont want to read the fine print or scratch their head at the Gas station ..Of what to pour in
Which sometimes goes wrong Mainly diesel into Petrol engines or vice versa When hauling it to a shop for action is needed.
So to sum it up again apologize if it is of topic and plain wrong
The electronics is much better in emission control and engine government than an old carburetor.
As long as the electronic is working it can handle the fuel which can contain water and ethanol at unknown concentrations which a XS 650 is not as good at
The electronic itself is something people swear at. The small red lamp at the dash board that the inspector at the MOT station detects that can lead to expensive repairs
At the brand dealer and special filters ( Catalysator ) that is so expensive that scrapping is the only solution.
As a side note the Fireblade has variable intake and Exhaust length if i recall right at 8000 rpm flaps are turned and
other flow paths are used for the upper revs .
Would suspect with different injector times.
I remember reading of the drag racers having the challenge of reprogramming these Chips and black boxes for achieving their goals whereas carburetors is different
Those black boxes have secrets not easily accessible jfr Volkswagen fraud.
Al; good points Jan P. Many engines are direct injection now which means you have a finite time to deliver a specific amount of fuel. I may be way off here.
Fddk
XS650 Member
Would aviation 100LL fuel be ok to run in the early XS’s. Closer to the fuels we used to have in the early 70’s. Higher octane, no ethanol and lead to protect the valves.
Last I was aware, 100LL is a lot of lead for your 650 engine. I’d expect lead deposits with regular use.
Plus, it’s expensive.
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Kind of tough getting in and out of airports to fuel up every 100 miles...........
I tend to run no ethanol premium but don't worry about splashing in some regular corn gas while on the road.
I tend to run no ethanol premium but don't worry about splashing in some regular corn gas while on the road.
Where I live I have no choice but to use 10% ethanol. I do run premium, on occasion have run regular with no problems.
I don't drain tanks or carbs for winter. Just park them.
I don't drain tanks or carbs for winter. Just park them.
Unlike Brit bikes of the early '70's, the XS650 engine was made with hardened valve seats from the start of production. For that reason the XS650 does not require leaded fuel and never did.
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