Gas tank and mileage

Marcb

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I have a 1970 750 with a fibre glass tank. What is the capacity and how many miles before a fill up? (Or when you need to open the reserve valve).
 

Knucles

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I rode one for years .
dont remember the capacity .
turn on the reserve when the engine starts to sputter .
then look for a gas bar.
just dont turn on reserve before you need it or you will be out of gas when it starts to sputter
 
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Which tank? Roadster, fastback, etc. The roadster tank range when I rode my 750 Commando Roadster (fiberglass tank )daily was around 100 miles - 90 was my personal "comfort limit." My Fastback tank holds a gallon + more so the range is around 140. NOTE: the reserve on my OEM Roadster fiberglass tank was about a cup of gas! So when it sputters and you flip to reserve, you need to find a gas station RIGHT NOW. I have personal experience with that. ;)
 

robs ss

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According to "Technical Data" in the workshop manual - in order of capacity:

SS & Highrider 9 litres
Roadster (GRP) 10 litres
Roadster (steel) 11 litres
Fastback 15 litres
LR Fastback 18 litres
Interstate (GRP) 24 litres
Interstate (steel) 25 litres

I haven't stated gallons due to potential confusion (Imperial/US)

Can't find a mention of reserve.
Cheers
 

texasSlick

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My first Atlas , a '62, had a 2 1/2 gallon tank and a range of approx. 125 - 140 miles including reserve, or averaged 50 to 55 mpg.

My present Atlas averages 45 to 50 mpg, and with a 2 1/2 gallon tank goes about 110 to 125 miles including reserve.

It is easy enough to determine the before reserve capacity of your tank. Right after you turn on reserve (because you have to), head for a fuel station and fill up, noting how much it took.

Measure your average mpg, then do the math.

Slick
 
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RoadScholar

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MPG depends mostly on how soon your right hand wants to wrap itself around a cold beer. Seriously, Google "hypermiling techniques".

I have one of the last Volvo rocket ships, it has flirted with 29 MPG (once), but I can't resist the feeling when 345 stock BHP gets unleashed; I generally get high teens to low 20s when my right foot misbehaves. Braking is almost as much fun, monster brakes. If a red sports car behaved this way the driver would be doing a lot of walking. The Ducatis I have owned had the same disease, but to a much higher degree.

Throttle movement, load, state of tune, altitude and more conditions have a measurable effect on fuel efficiency. I always blame my right wrist or right foot, never my fault...

Best.
 

Tornado

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I could do around 80 miles reliably on my HiRider 9 litre tank, running a single 932 carb on my 850. With two carbs MPG seemed to drop some but I'd switched to Roadster tank before adding second carb, so total miles before fill up was higher...typically 120+.

Note that reserve capacity is highly dependant on the taps you are running (different stand pipe lengths) and how much lean angle/bumps/up or down hill work has been done as fuel sloshes out or into the reserve side.
 

HRD

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According to "Technical Data" in the workshop manual - in order of capacity:

SS & Highrider 9 litres
Roadster (GRP) 10 litres
Roadster (steel) 11 litres
Fastback 15 litres
LR Fastback 18 litres
Interstate (GRP) 24 litres
Interstate (steel) 25 litres

I haven't stated gallons due to potential confusion (Imperial/US)

Can't find a mention of reserve.
Cheers
There are two different shapes of Interstate steel tanks so different capacity ?
 
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There are two different shapes of Interstate steel tanks so different capacity ?
At least 2,

1. Fibreglass to steel with a capacity increase.

2. Change on the steel where the rear was narrowed reducing capacity and there may be other changes.
 

robs ss

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Thanks - but there's nothing definitive there about different capacities of interstate steel tanks - which is what @HRD was asking in post #12
 
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Re gas mileage - back in the day on my '71 750, I typically got fuel consumption in the mid/upper 30s (MPG). The claims of 50-some MPG just doesn't compute for me on an OEM dual carb Commando. Admittedly, I rode much more aggressively then than I do now but I still can't imagine how it's possible to get 50MPG on a stock Commando unless it's being ridden VERY conservatively. ;)
 
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Re gas mileage - back in the day on my '71 750, I typically got fuel consumption in the mid/upper 30s (MPG). The claims of 50-some MPG just doesn't compute for me on an OEM dual carb Commando. Admittedly, I rode much more aggressively then than I do now but I still can't imagine how it's possible to get 50MPG on a stock Commando unless it's being ridden VERY conservatively. ;)

Gearing?
 
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