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Discussion Starter · #1 ·
My ST3s ABS is listed as having a 5.5gal tank, however the most I've ever put into it is 4.65 gal, and the low fuel light had been on for over 20 miles. Not that I ever intend to run it dry, but when in remote places it might be good to know how many miles/gallons I really have when the light comes on.

Does it really have 5.5 gal of usable fuel or will there always be a small amount (1/2 gal?) in the bottom of the tank that the fuel pump will never pick up?

thx
 

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Mr Leakered
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I've put 5.1 to 5.2 gallons in fair regularly in my ST4.

I usually add 40mi to the trip reading just after the low fuel light pops on to determine how long I have to go. Lately, I'm thinking of adding 50mi because I'm filling up with about 4.8gal with 210mi or so on the trip odo. My mileage has improved quite a bit after I swapped plug wires.

Have a good one.
 

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martys

A few months ago I ran out of gas due to procrastination (1st time in my life). Pushed a short distance to a gas station and filled up. Can't remember exactly, but I think I was able to add just over 5 gallons. A couple times after initial stalling I was able to slosh the fuel around enough to get her going for a few hundred feet.

Defiantly some un-usable fuel left in the tank.
 

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Discussion Starter · #4 ·
I've put 5.1 to 5.2 gallons in fair regularly in my ST4.

I usually add 40mi to the trip reading just after the low fuel light pops on to determine how long I have to go. Lately, I'm thinking of adding 50mi because I'm filling up with about 4.8gal with 210mi or so on the trip odo. My mileage has improved quite a bit after I swapped plug wires.

Have a good one.
which wires did you replace the stock ones with? I've heard great things about magnecor wires. how did you solve the custom end problem? or does the ST4 use normal end plug caps?
 

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Mr Leakered
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I wanted the magnecors also, but I was on the fence with the cost. I happened on the set that TPO Parts sells (8.5mm MSD) while buying some clutch bits. The set they fabbed from my heads were great. Long-term, it bumped my MPG by 4 to 5, but the old set was 9yrs old.

With your DS heads, it will be a different story. Allan at TPO worked with me to ensure all was good. You may want to drop them a line with regard to the ST3.

That and comments on their parts labels are just great.

Have a good one.
 

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I've put 5.3 gallons in mine a couple of times. It was running fine before I filled up. I watched my friend put 5.6 gallons in his ST4 tank. He was really low but it hadn't sputtered yet.

Previously, I figured at least 40 miles after the low fuel light comes on but I now know I have at least 80 miles left as long as I'm on the open road going 65-80 mph and it's not really cold out.
 

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Discussion Starter · #7 ·
I've put 5.3 gallons in mine a couple of times. It was running fine before I filled up. I watched my friend put 5.6 gallons in his ST4 tank. He was really low but it hadn't sputtered yet.

Previously, I figured at least 40 miles after the low fuel light comes on but I now know I have at least 80 miles left as long as I'm on the open road going 65-80 mph and it's not really cold out.
thanks Mike! so maybe my bike really does have a 200 miles range if I allow 50-60 miles once the light goes on. this is really good to know.
 

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thanks Mike! so maybe my bike really does have a 200 miles range if I allow 50-60 miles once the light goes on. this is really good to know.
I would hope so!

The furthest I've ever ridden on one tank was 283 miles but I couldn't quite fit 5 gallons in so I know I had another 30 miles left. A friend went over 300 miles on his ST4s two-up with panniers and top-case without sputtering or running out.

I have the DP ECU and open airbox/DP Carbon Fiber pipes. It is a real performer and has very good fueling (smooth throttle response) even at low rpm's. Power is excellent. My odometer has been checked and is very accurate (unlike the speedometer). Good range is simply a matter of proper tune and keeping friction to a minimum (chain lubed and proper tire pressure, good wheel bearings).
 

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Discussion Starter · #9 ·
I would hope so!

The furthest I've ever ridden on one tank was 283 miles but I couldn't quite fit 5 gallons in so I know I had another 30 miles left. A friend went over 300 miles on his ST4s two-up with panniers and top-case without sputtering or running out.

I have the DP ECU and open airbox/DP Carbon Fiber pipes. It is a real performer and has very good fueling (smooth throttle response) even at low rpm's. Power is excellent. My odometer has been checked and is very accurate (unlike the speedometer). Good range is simply a matter of proper tune and keeping friction to a minimum (chain lubed and proper tire pressure, good wheel bearings).
that's astonishing from my experience with the ST3s over the last year. I have the DP ecu, CF exhaust, open air box, power commander and custom map so I know a/f mix is right at 13:1 throughout the throttle range. With all this it's running really smooth and I've confirmed with Gunson analyzer the exhaust is at about 4.5-5.0% CO2. It runs super smooth, but the best mileage I've seen on long trips if 42-44 mpg, under 40 when ripping through twisties and sweepers. You're talking about nearly 60 mpg?!
 

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I've had just over 200 miles per tank out of my ST4 on a number of occasions but haven't pushed it further than that.
I've also run it till it was bone dry on one (unplanned) occasion.
The low fuel light illuminates on my ST4s after using slightly more than half a tank.
 

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that's astonishing from my experience with the ST3s over the last year. I have the DP ecu, CF exhaust, open air box, power commander and custom map so I know a/f mix is right at 13:1 throughout the throttle range. With all this it's running really smooth and I've confirmed with Gunson analyzer the exhaust is at about 4.5-5.0% CO2. It runs super smooth, but the best mileage I've seen on long trips if 42-44 mpg, under 40 when ripping through twisties and sweepers. You're talking about nearly 60 mpg?!
Two different engines. The 4 valve engines (and the ST4s engine in particular) typically provide more range than the 2V and 3V engines.

Yes, at a relatively steady 65-70 mph my ST4s returns just under 60 mpg, but only during warm weather (above 80 degrees). But I generally don't ride at a steady speed (at least not that slow). More typically I get 44 mpg with mostly twisties. That is with cooler temperatures, lots of right wrist action and higher peak speeds. If I am riding twisties full on with hard braking into the corners and plenty of triple digits speeds it will drop below 40 mpg.

I'm not a fan of piggy-back devices like the Power Commander because I have heard of too many failures. The PC does not replace any components but it does add one more that could fail. I also do not know how much delay is added to the injection pulse. It certainly doesn't make it happen any sooner as it has it's own look-up tables, etc.
 

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Yesterday my light came on at 190 miles, including 75 miles of twisties, I rode to 203 and filled it with 4.2 gallons. I was sweating it a bit though, not knowing how far I could go, the reserve is a bit too generous.
 

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Life is too short to worry !
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One thing that may throw people off when comparing is the occasional dishonest fuel station with pumps set to show more fuel going in than actually is.
It happens over here enough to be a factor but the pumps are chceked by our DOT to try and get rid of the bad boys.

I get a light at 2 bars and look to fill up close to 40 miles later and usually with about 2-220 Mls on the clock but often dont have a choice than to full up early here , particularly on a Sunday when a lot of the few pumps can be shut.
Like Bill the figure can drop if get enthusiastic - down to 160'ish.
 

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One thing that may throw people off when comparing is the occasional dishonest fuel station with pumps set to show more fuel going in than actually is.
It happens over here enough to be a factor but the pumps are chceked by our DOT to try and get rid of the bad boys.

I get a light at 2 bars and look to fill up close to 40 miles later and usually with about 2-220 Mls on the clock but often dont have a choice than to full up early here , particularly on a Sunday when a lot of the few pumps can be shut.
Like Bill the figure can drop if get enthusiastic - down to 160'ish.
Very good point. I know it's suppose to be regulated here but I bet it still happens.
 

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You could always take a look in the tank (just like I didn't when I ran mine bone dry)
I empty my tank when I pull the pump and of course pump some back in so I can ride to the nearest gas station. Looking in there it's impossible for me to tell how much fuel there is or how far it will get me.
 

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One thing that may throw people off when comparing is the occasional dishonest fuel station with pumps set to show more fuel going in than actually is.
That's a good point. Here in the U.S. it's regulated state by state. In Washington State the Department of Weights and Measures do periodic checks for pump accuracy. The accuracy standards are very strict but they allow a larger margin for error if the pump is overly generous and a much smaller margin on the stingy side. Recent checks by the State show that consumers get more than they pay for more often than they get less but, because the accuracy standards are so high, the variation is very small. Other states may be more lenient, I don't know.

Stations in Washington State tend to keep their pumps well calibrated because it is cheaper than dealing with State violations.
 

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Something to keep in mind. The early cable speedometers are 10% optomistic (do not know about the digital speedos), so real mileage is inflated by 10%. 220 miles is really 200 for instance.
 

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Something to keep in mind. The early cable speedometers are 10% optomistic (do not know about the digital speedos), so real mileage is inflated by 10%. 220 miles is really 200 for instance.
Inaccurate speedo does not indicate inaccurate odometer.

Two different things. My odometer is almost dead on while my speedo reads almost 10% fast at legal speeds.

220 miles is 220 miles.
 

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I get high 30's out of mine, low 40's sometimes. My riding buddy has an ST1300 and we get nearly identical fuel mileage. But truthfully, I've never had mine tuned, and it has 23,000 miles on it now. I do all my own work and have done a valve adjustment and belt change, but haven't tried any tuning changes. It may run a little rich, but it runs well, so I have left it alone.
 
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