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Offline CaptainTrips

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Re: Mysteriously bad fuel economy
« Reply #10 on: July 13, 2019, 06:20:38 PM »
*Originally Posted by Aryeh56 [+]
Sure enough, the rear brake is awfully hot. Not burn-your hand hot, but it probably would be if I touched it immediately after stopping. It also isn't self adjusting correctly, so something is stuck. IDK if the return spring is out of wack, or it's something inside the caliper. I remember it being a surprisingly tight squeeze when I first put it on, so Hawk may be right about it being the wrong generation of the pad. I'll have to take it off again and investigate tomorrow.

As for gas smells, its present on start-up but goes away fairly quickly. I can't tell you what it smells like in a garage, because I'm not lucky enough to own a garage :012: I did the force-adjustment in a gas station parking lot, so I was sitting right next to it at idle for 12 minutes and the smell didn't become noticeable.  :027: Still, I can't imagine a rubbing brake pad sliced off a whole 1/3 of my fuel economy. They are EBC 2HH pads, so just rubbing would've probably been some substantial friction, but not like that!

Edit: It does sound like its running rich, but its always sounded like that. I have been crosschecking the mileage with the odometer readings, and the meter at the gas station, and it sure seems like the dash is right.
Remove the caliper and just clean everything up with brake cleaner and a toothbrush. Use brake silicon grease on the caliper pins. You should be able move the piston back with your fingers pressing on a thin piece of wood when you are done the cleaning. You should not need to disassemble the piston assembly. Just (CAREFULLY) work the piston in and out a small amount with the peddle and your fingers and clean with brake cleaner each time you extend the piston (no more than 1/4 inch).

As to the 12-minute tune up, if you did it at a gas station, then it probably was not successful. The engine must be cold to start. And at no time do you touch the throttle during the reset. Key on, start the bike, let it idle until the fan comes on, then start timing for 12 minutes, then key off without touching the throttle at any time.
« Last Edit: July 13, 2019, 06:24:11 PM by CaptainTrips »
"The test of the machine is the satisfaction it gives you. There isn't any other test."   --   Robert M. Pirsig

Offline Tiger T.O.

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Re: Mysteriously bad fuel economy
« Reply #11 on: July 13, 2019, 07:39:22 PM »
 :460: As for dragging rear brake: my normal "mileage" was 20 kms per litre and at last was down to 16 kms per litre  :033:
The penny dropped when I started to notice it was ever getting harder to push the bike backwards out of my garage :187: :084: :164:
After servicing and renewing brake pads all is well again :-)
« Last Edit: July 13, 2019, 07:42:33 PM by Tiger T.O. »
There are two kinds of people, those saying the glass is half full and those saying the glass is half empty. But the world really belongs to the ones that say “That’s not my glass! My glass was full! And it was a bigger glass!”             Terry Pratchett  R.I.P.

Offline Hawk281

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Re: Mysteriously bad fuel economy
« Reply #12 on: July 14, 2019, 05:21:44 AM »
on calling ebc, they were the ones to pull the pad out of stock and measure them against stock. couldn't explain why they were 9 mm thicker. they were the hh 2's. they were kind enough to send a new set the next day. installed them and issues went away.

Offline bixxer bob

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Re: Mysteriously bad fuel economy
« Reply #13 on: August 12, 2019, 10:38:57 PM »
I had a, period where my 2013 model had adapted itself rich and fuel consumption was high. It turned out to be an air leak on the air injection system.
How it works is this... In order to meet emission targets, air bleeds from the air box, through a valve to reed valves in the cam cover. From there the air follows two galleries through the cylinder head and into the exhaust where it transfers into the header pipes. Injecting air here burns residual fuel in the exhaust thus cleaning the emissions but also causing exhaust popping. The difficulty here is the ECU  monitors the exhaust mixture via the O2 sensor in certain circumstances and trims the mixture either rich or lean depending on what the O2 reads. Bleeding air into the exhaust will cause a false reading (lean) and the ECU will richen the mix. To prevent that happening, as the ECU reads the O2 sensor it closes the airbox valve thus shutting off the bleed air.

Having understood that, its easy to see that any air leak downstream of the valve is going to cause a rich mixture eventually. In my case it was a web from the gasket for the three plug holes that had become trapped in an air gallery after a valve clearance check and preventing a good seal.  Took some finding though :021:

Offline eps

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Re: Mysteriously bad fuel economy
« Reply #14 on: August 12, 2019, 11:14:34 PM »
Thats a really good piece of info Bob - genuinely thanks .  :001:

Offline bixxer bob

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Re: Mysteriously bad fuel economy
« Reply #15 on: August 13, 2019, 06:17:01 AM »
It's good to share :015:  :001:

Offline Aryeh56

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Re: Mysteriously bad fuel economy
« Reply #16 on: August 18, 2019, 07:32:40 PM »
*Originally Posted by bixxer bob [+]
I had a, period where my 2013 model had adapted itself rich and fuel consumption was high. It turned out to be an air leak on the air injection system.
How it works is this... In order to meet emission targets, air bleeds from the air box, through a valve to reed valves in the cam cover. From there the air follows two galleries through the cylinder head and into the exhaust where it transfers into the header pipes. Injecting air here burns residual fuel in the exhaust thus cleaning the emissions but also causing exhaust popping. The difficulty here is the ECU  monitors the exhaust mixture via the O2 sensor in certain circumstances and trims the mixture either rich or lean depending on what the O2 reads. Bleeding air into the exhaust will cause a false reading (lean) and the ECU will richen the mix. To prevent that happening, as the ECU reads the O2 sensor it closes the airbox valve thus shutting off the bleed air.

Having understood that, its easy to see that any air leak downstream of the valve is going to cause a rich mixture eventually. In my case it was a web from the gasket for the three plug holes that had become trapped in an air gallery after a valve clearance check and preventing a good seal.  Took some finding though :021:

Thanks for the tip, Bob! It turned out to be more than just rubbing pads for me, so now I am back to tracking down a rich mixture issue. What I've noticed on mine is that its especially bad at idle. As of today its to the point where I can smell it at stoplights, though that's a new development. Last time I ran diagnostics, the only thing I noticed that seemed weird was that sometimes the O2 sensor would misbehave at idle. Under load it would range as expected from .25 to .8 volts and back. Sometimes when I rolled off though it would drop to 0.04 and just stay there. I tried cleaning the sensor but that does not appear to have resolved the problem. Anyone have any good diagnostic suggestions?

Offline anaheimtex

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Re: Mysteriously bad fuel economy
« Reply #17 on: August 18, 2019, 08:30:52 PM »
As far as rubbing pad, if they were rubbing enough to affect mileage they would be burning off skin if you touched them. Air pressure for tires and running rich is a big factor. Use a brake cleaner and spray the air intake area while idling. If there is an intake leak the engine will stumble.
don't come to a cat forum saying you should have bought a dog.

Offline bixxer bob

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Re: Mysteriously bad fuel economy
« Reply #18 on: August 18, 2019, 09:21:07 PM »
*Originally Posted by Aryeh56 [+]
Thanks for the tip, Bob! It turned out to be more than just rubbing pads for me, so now I am back to tracking down a rich mixture issue. What I've noticed on mine is that its especially bad at idle. As of today its to the point where I can smell it at stoplights, though that's a new development. Last time I ran diagnostics, the only thing I noticed that seemed weird was that sometimes the O2 sensor would misbehave at idle. Under load it would range as expected from .25 to .8 volts and back. Sometimes when I rolled off though it would drop to 0.04 and just stay there. I tried cleaning the sensor but that does not appear to have resolved the problem. Anyone have any good diagnostic suggestions?

Ok, based on what I've learned so far, re your rich smell, three things come to mind.  First, (I assume you're using Dealertool) do a functional test on the air recirculation valve in the  airbox.  If it's stuck open or not sealing properly it'll leak air into the exhaust when the ECU is sensing the mixture via the O2 sensor and it'll go rich. Then check the air hose that runs from the air box to the reed valves for leaks and that it's seated correctly with the clips firmly in place.  Next, check the reed valves in the cam cover aren't stuck, stuck open, or broken.  I've heard of both happening albeit on an 800.  Lastly is the fault that caused mine ie the gasket issue, but you have to take the cam cover off to check that (so while you're in there you might as well check your valve clearances eh?).  To be fair, if neither you or the dealer have been in there recently it's unlikely to be that.  Good luck!

BTW, the O2 sensor is narrow band so the swinging is normal, 0.49v is a good reading.  I'm hoping you didn't damage it while cleaning......  Oh, and do the 12 minute tune once you've finished to reset the trims
« Last Edit: August 18, 2019, 09:28:58 PM by bixxer bob »

Offline Aryeh56

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Re: Mysteriously bad fuel economy
« Reply #19 on: August 19, 2019, 04:47:00 PM »
*Originally Posted by bixxer bob [+]
Ok, based on what I've learned so far, re your rich smell, three things come to mind.  First, (I assume you're using Dealertool) do a functional test on the air recirculation valve in the  airbox.  If it's stuck open or not sealing properly it'll leak air into the exhaust when the ECU is sensing the mixture via the O2 sensor and it'll go rich. Then check the air hose that runs from the air box to the reed valves for leaks and that it's seated correctly with the clips firmly in place.  Next, check the reed valves in the cam cover aren't stuck, stuck open, or broken.  I've heard of both happening albeit on an 800.  Lastly is the fault that caused mine ie the gasket issue, but you have to take the cam cover off to check that (so while you're in there you might as well check your valve clearances eh?).  To be fair, if neither you or the dealer have been in there recently it's unlikely to be that.  Good luck!

BTW, the O2 sensor is narrow band so the swinging is normal, 0.49v is a good reading.  I'm hoping you didn't damage it while cleaning......  Oh, and do the 12 minute tune once you've finished to reset the trims

Thanks a ton! That hose and its clips was the first thing I was going to check. I'll try that test too! If need be, I actually have a replacement on hand for the valve on the airbox. I picked up a whole box full of miscellaneous engine parts from a salvage yard not too long ago. I'm going to cross my fingers that its not the reeds. Triumph of Frederick just did my valve adjustment 2000 miles ago, when these symptoms had already started. The mechanic there is a wiz, so he would've caught it, I think.

As for the O2 sensor, I know the wave-form reading is normal. It's when it hovers for a long time at 0.04 that worries me. It'll be twenty seconds at least of staying at that figure, maybe a lot more. After I cleaned the sensor I checked the readings again and it showed very little change, so I don't think I hurt it, at least. I'll check it again when I have it back on dealertool to test the emissions valve.

Thanks for all the help! I'll let you know how it goes!

 


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