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bad for mpg? leaving the fast idle lever up


co_g30

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I've had my 2004 R1150RT for less than a month, and loving it. I am getting better about it but sometimes I forget to turn off the fast idle lever so the engine idles higher than usual. My question is this, am I harming mpg by doing so? I am thinking perhaps only when at idle at stoplights but not when at riding speeds?

 

tia

 

co_g30

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I've had my 2004 R1150RT for less than a month, and loving it. I am getting better about it but sometimes I forget to turn off the fast idle lever so the engine idles higher than usual. My question is this, am I harming mpg by doing so? I am thinking perhaps only when at idle at stoplights but not when at riding speeds?

 

tia

 

co_g30

 

The fast idle lever is connected to the throttles via a junction box under the battery. All it does is open the throttle slightly. As soon as you twist the grip it does nothing, so your assumptions are correct.

 

The important thing is to NOT let the bike sit at high idle whilst stationary for any time at all and NEVER leave the bike unattended at high idle. This will cause the engine overheat and has been known to cause fire although a failed HES is more common. It can also cause the oil sight glass to melt and dump the sump's contents with predictable results.

 

Andy

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co_g30, to answer your question: yes you are hurting your fuel economy but as you say ONLY when at idle or at closed throttle that would normally be below what the fast idle lever holds the idle RPM at.. Stop & go traffic it will probably be measurable.. HiWay riding probably not noticeable..

 

Twisty

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I've had my 2004 R1150RT for less than a month, and loving it. I am getting better about it but sometimes I forget to turn off the fast idle lever so the engine idles higher than usual. My question is this, am I harming mpg by doing so? I am thinking perhaps only when at idle at stoplights but not when at riding speeds?

 

tia

 

co_g30

 

The fast idle lever is connected to the throttles via a junction box under the battery. All it does is open the throttle slightly. As soon as you twist the grip it does nothing, so your assumptions are correct.

 

The important thing is to NOT let the bike sit at high idle whilst stationary for any time at all and NEVER leave the bike unattended at high idle. This will cause the engine overheat and has been known to cause fire although a failed HES is more common. It can also cause the oil sight glass to melt and dump the sump's contents with predictable results.

 

Andy

 

ABout how long does it take to overheat at say 70 degrees ambient? I let my RT warm up for about 3 - 5 minutes (but never unattended). A member told me about a person leaving their RT in high idle unattended for so long it melted the lower fairing.

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The others are right about the fast idle being left up not affecting your fuel econ off idle. But, not only are you hurting your fuel econ at idle, you're also causing more (albeit slight more) brake wear and increasing your stopping distance with the fast idle engaged.

 

My cold start drill on my 02 RT is this:

 

1)Dawn helmet, gloves and plug in Autocom lead

 

2)Pull fast idle lever ALL the way up

 

3)Start bike and let run until engine rpm rises above 2K

 

4)Release start lever and let it stay in the middle (fast) detent

 

5)Put bike in gear and ride away.

 

6)After pulling out on highway 1/4 mile from house, stow fast idle lever.

 

I ride guarding the clutch and brake levers with my index finger, so all I have to do is in between gear changes, just flip my left index finger over a hair and stow that fast idle lever.

 

BTW, the warning on getting the oil hot by allowing it to sit is to be heeded. My sight glass let go, but fortunately only a mile from my house.

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The others are right about the fast idle being left up not affecting your fuel econ off idle. But, not only are you hurting your fuel econ at idle, you're also causing more (albeit slight more) brake wear and increasing your stopping distance with the fast idle engaged.

 

My cold start drill on my 02 RT is this:

 

1)Dawn helmet, gloves and plug in Autocom lead

 

2)Pull fast idle lever ALL the way up

 

3)Start bike and let run until engine rpm rises above 2K

 

4)Release start lever and let it stay in the middle (fast) detent

 

5)Put bike in gear and ride away.

 

6)After pulling out on highway 1/4 mile from house, stow fast idle lever.

 

I ride guarding the clutch and brake levers with my index finger, so all I have to do is in between gear changes, just flip my left index finger over a hair and stow that fast idle lever.

 

BTW, the warning on getting the oil hot by allowing it to sit is to be heeded. My sight glass let go, but fortunately only a mile from my house.

 

agree.."choke it" ride down driveway, click fast idle off and just ride. maybe 60 seconds in all. a 10 minute "warm-up" with either fast idle or just running seems a bit excessive.

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agree.."choke it" ride down driveway, click fast idle off and just ride. maybe 60 seconds in all. a 10 minute "warm-up" with either fast idle or just running seems a bit excessive.
With my '04 I fall between this range. 60 seconds would not be long enough (I have a very short driveway), but 5 minutes (about the time it takes for the first temp bar to appear) seems long enough to warm the bike enough not to stall at "normal" idle (my bike's idle might be a bit low to start with).

 

Note: I've been operating under the assumption that a "warm up", i.e. before riding away, is not required nor is it recommended.

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ABout how long does it take to overheat at say 70 degrees ambient? I let my RT warm up for about 3 - 5 minutes (but never unattended).

That's a bad plan, my friend. More than one person has melted their fairings or destroyed their Hall sensor by doing just that. One guy burned his garage down after the fuel line melted.

 

Just start the bike and ride. Use the fast idle to keep the idle up a little bit for the first few minutes. When temp guage reaches three bars, you are good-to-go.

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ABout how long does it take to overheat at say 70 degrees ambient? I let my RT warm up for about 3 - 5 minutes (but never unattended).

That's a bad plan, my friend. More than one person has melted their fairings or destroyed their Hall sensor by doing just that. One guy burned his garage down after the fuel line melted.

 

Just start the bike and ride. Use the fast idle to keep the idle up a little bit for the first few minutes. When temp guage reaches three bars, you are good-to-go.

 

Thanks for the warning. I suppose I dont really do it for 5 minutes. I did it tonight and it was more like 2 minutes.

 

Either way - point taken.

 

Thanks

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Here is some bad news good news. I was one of those who melted the lower fairings pieces, warped my oil sight glass and burned up the HES. I was under the mistaken impression that I should start it a few times during the winter. That's the bad news.

 

The good news is the folks on this web site were very helpful and patient walking me through the repair process. Unfortunately, they get to do it all too often. The HES tested okay with the LED test device but still ended up being bad.

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Here is some bad news good news. I was one of those who melted the lower fairings pieces, warped my oil sight glass and burned up the HES. I was under the mistaken impression that I should start it a few times during the winter. That's the bad news.

 

The good news is the folks on this web site were very helpful and patient walking me through the repair process. Unfortunately, they get to do it all too often. The HES tested okay with the LED test device but still ended up being bad.

 

How long did you let the bike idle for to cause the damage?

 

What does the HES do?

 

Thanks

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Joe Frickin' Friday
What does the HES do?

 

Tells the Motronic the orientation of the crankshaft. The computer receives one signal from the sensor when the crank/piston is at TDC, and another when at BDC; it uses these signals (in conjunction with a whole pile of info from other sensors) to determine when to inject fuel or fire the spark plugs.

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It will be no worse than slightly opening the throttle to increase the idle RPM, since this is exactly what the lever does.

 

The only other thing is that depending on how your closed throttle switch is adjusted, it is possible that opening the lever will prevent the switch from closing when you are decellerating with a closed throttle. This will prevent the injectors from shutting off as you decellerate, and in turn will very slightly affect fuel economy (probably too slightly to notice).

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I appreciate that I don't suffer the extreme low temperatures that some of you guys do but basically I pull the choke lever to the detent point, start the bike and drive off as soon as the chain tensioner noise stops.

I keep the revs reasonable until 1 bar shows on the oil temperature gauge then I drive normally.

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My cold start drill on my 02 RT is this:

 

1)Don helmet, gloves and plug in Autocom lead

 

2)Pull fast idle lever ALL the way up

 

3)Start bike and let run until engine rpm rises above 2K

 

4)Release start lever and let it stay in the middle (fast) detent

 

5)Put bike in gear and ride away.

 

6)After pulling out on highway 1/4 mile from house, stow fast idle lever.

That's my routine exactly, except for the Autocom bit. thumbsup.gif

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Comment on fast idle lever usage: When I'm having fun on a tight twisty road, riding around 5000/6000 rpm in second gear, sometimes I have the lever on first notch. Without it I can feel the lurching of the fuel shutting off with closed throttle and coming on again when I open the throttle. With the lever on it does not shut off the fuel. The way I have it adjusted, with the lever on and warm engine it idles at around 1300 rpm, not high enough to affect engine braking. Throttle off/on transitions are smoother.

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If my memory serves me correctly - my owner's handbook says to start the bike and ride off. And that's exactly what I do. I kit up, straddle the bike, turn the key, lift the idle advance, hit the starter, engage first gear, drop the idle advance AND RIDE.

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My cold start drill on my 02 RT is this:

 

1)Don helmet, gloves and plug in Autocom lead

 

2)Pull fast idle lever ALL the way up

 

3)Start bike and let run until engine rpm rises above 2K

 

4)Release start lever and let it stay in the middle (fast) detent

 

5)Put bike in gear and ride away.

 

6)After pulling out on highway 1/4 mile from house, stow fast idle lever.

That's my routine exactly, except for the Autocom bit. thumbsup.gif

 

update: it appears as if I have to adjust the fast idle cable, when in fully up position, engine idles at around 1000-1100 but does not climb to 2000 as apparently others do?

 

also, in the mid position, it sometimes idles at 1000-1100 and sometimes it does not, idling then at normal 900.

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