Fuel Economy sudden drop

[PeteR1200]

Was hoping someone could shed some light,

 

My Fuel economy suddenly dropped from 46mpg to 36 mpg.  it has 46500 miles on it.

 

What I found was.  A sparkplug in each cyclinder had not been properly tightened.  Figured while I was at it then I would do the 48k early.

this is what has been done.

1. Checked vavle clearances.  Mostly good but both exhaust vavles on #2 where at 0.15mm not the 0.3.

2. Plugs chainged for new ones, the old ones, even the lose ones looked good, noticeably gap wear.

3. Checked the values with a GS911, I have attached the csv file.

4. Using a Twinmax checked the balancer.  looked pretty good, I think.  At idle it was off > 0.5 then perfect at above 2500.

5. Cleared the mapping and rode it for a couple of hours, bike seems a little smoother, or I am imagining it!!

 

Ther have been a couple of times over the last few months, when idling that it would just stop and then re-started fine, not sure if that relates to anything.

 

Bike is running very well.

 

I will run a logged fuel consumption test in case the foil is acting up and the computer is misreporting.  I would think with a 21% increase in fuel consumption the bike would not be running the same.

 

I appreciate any insight anyone can give me.

 

Also,  on another note.  Had problems with cruise control not operating and not able to start the bike in gear with the side stand up (stalled it traffic, embarrasing!!).  Cleaned the two microswitch in the clutch handle and a slight adjustment and that works great now.

 

 

thanks,

 

Pete

 

2022-07-03-1440-BMSK.csv

[dirtrider]

28 minutes ago, PeteR1200 said:

Was hoping someone could shed some light,

 

My Fuel economy suddenly dropped from 46mpg to 36 mpg.  it has 46500 miles on it.

 

What I found was.  A sparkplug in each cyclinder had not been properly tightened.  Figured while I was at it then I would do the 48k early.

this is what has been done.

1. Checked vavle clearances.  Mostly good but both exhaust vavles on #2 where at 0.15mm not the 0.3.

2. Plugs chainged for new ones, the old ones, even the lose ones looked good, noticeably gap wear.

3. Checked the values with a GS911, I have attached the csv file.

4. Using a Twinmax checked the balancer.  looked pretty good, I think.  At idle it was off > 0.5 then perfect at above 2500.

5. Cleared the mapping and rode it for a couple of hours, bike seems a little smoother, or I am imagining it!!

 

Ther have been a couple of times over the last few months, when idling that it would just stop and then re-started fine, not sure if that relates to anything.

 

Bike is running very well.

 

I will run a logged fuel consumption test in case the foil is acting up and the computer is misreporting.  I would think with a 21% increase in fuel consumption the bike would not be running the same.

 

I appreciate any insight anyone can give me.

 

Also,  on another note.  Had problems with cruise control not operating and not able to start the bike in gear with the side stand up (stalled it traffic, embarrasing!!).  Cleaned the two microswitch in the clutch handle and a slight adjustment and that works great now.

 

 

thanks,

 

Pete

 

2022-07-03-1440-BMSK.csv 32.78 kB · 0 downloads

Evening Pete

 

I don't see any smoking gun in the trapped .CSV data, the additive trims are a little unequal but not a real concern, especially given the data was all taken at idle. 

 

To get anything meaningful that could be effecting your fuel economy you really need to set your GS-911 to trap about 1/2 hour of actual on-road varied riding. (you aren't losing your fuel economy at idle so you need to trap data in the ranges that you ride it in).

 

You also need to check your milage against the actual fuel added vs miles traveled as sometimes the onboard fuel computer can be in error (especially if you don't clear/reset it at every fill-up). 

 

Or it could be as simple as getting some very low octane fuel (some gas stations will cheat & put some low quality gasoline in the premium tank). Your 1200 has knock sensors so with low octane fuel it can pull a lot of spark advance out at road load & lower the fuel mileage. 

 

If you get a chance you might check your air filter for being partially plugged. I worked on a 1200RT a while back that had poor fuel economy, I found an orange  shop rag blocking a lot of the air filter. When I asked the owner about the shop rag he told me he stuffed it into the air intake before winter storage to keep mice out of the air filter then forgot to take it out in the spring. 

[PeteR1200]

Hello Dirtrider,

 

Thanks for getting back to me.

 

I forgot to mention, I did replace the air filter.

 

I will try the extended running log with the GS911.

 

Pete

[PeteR1200]

Good Morning,

 

I rode the bike into work today so I was able to get the live data while riding my normal route.

 

One thing that bothers me is the ignition timing, it goes from -96 to -69, 27o delta.  There are a couple of times the timing went positive at 439969ms and 491731 ms.  Interesting to note the engine RPM went to zero from 486486ms to 490982ms

 

The bike is running really well, no evidence of soot at the exhaust, has good solid acceleration.  I am doing a real log of fuel usage incase the I am getting the incorrect reading from the foil.

2022-07-06-0727-BMSK.csv

[dirtrider]

1 hour ago, PeteR1200 said:

Good Morning,

 

I rode the bike into work today so I was able to get the live data while riding my normal route.

 

One thing that bothers me is the ignition timing, it goes from -96 to -69, 27o delta.  There are a couple of times the timing went positive at 439969ms and 491731 ms.  Interesting to note the engine RPM went to zero from 486486ms to 490982ms

 

The bike is running really well, no evidence of soot at the exhaust, has good solid acceleration.  I am doing a real log of fuel usage incase the I am getting the incorrect reading from the foil.

2022-07-06-0727-BMSK.csv 439.96 kB · 0 downloads

Morning PeteR1200

 

I will look at you logged data later today as I am on a remote work computer so will not open posted files on that computer.

[PeteR1200]

Thank you D.R.

[dirtrider]

16 minutes ago, PeteR1200 said:

Thank you D.R.

Morning PeteR1200

 

It will help with understanding the data if you can tell me the vehicle model year & if possible the approximate build date. Year of build & if an early or late build in that year is probably enough info. 

[PeteR1200]

It is a 2005 R1200rt, Build date is 0205.

 

Plotting the data it looks like the Lamnda control factor on #1 appears to be running richer, if I understand the data correctly.

[dirtrider]

3 minutes ago, PeteR1200 said:

It is a 2005 R1200rt, Build date is 0205.

 

Plotting the data it looks like the Lamnda control factor on #1 appears to be running richer, if I understand the data correctly.

Afternoon Pete

 

Not actually running richer just needs a little more correction to keep it within limits (not really unusual). 

 

 

 

 

[PeteR1200]

Correct me if I am wrong, but nothing in the data says 20% increase in consumption.

 

 

[dirtrider]

22 minutes ago, PeteR1200 said:

Correct me if I am wrong, but nothing in the data says 20% increase in consumption.

 

 

Afternoon Pete

 

I need to look at your logged data first to give you an educated answer. 

 

 

[dirtrider]

3 hours ago, dirtrider said:

Morning PeteR1200

 

I will look at you logged data later today as I am on a remote work computer so will not open posted files on that computer.

Afternoon Pete

 

OK, I looked at your data, not in deep detail as I had to borrow a co-workers personal laptop. 

I don't see a smoking gun as far as fuel economy loss goes but will point out a couple of things.

 

Note, the cylinder head temperature L & R differences, that ONLY happens on the early 1200 hexhead engines as the early hexhead engines  had a cylinder temp sensor on each cylinder head. The later 1200 hexheads only had one cylinder head temp sensor & that was shared by both sides in the BMS-K (so on the later hexhead engines you will always see the same cylinder temp for both cyl heads)

 

I don't see any wide open throttle movement so you might run another short run & go to wide open throttle a couple of times just to see  if the data shows it. 

 

Another thing__ after your first data log that shows that all the switches & sensors are working then, personally, I usually turn off data logging on most non-useful items as that makes the data MUCH easier to track in Excel. 

 I usually leave out wheel sensors, gear position, odometer, ambient air pressure, vehicle speed (unless I need that for some reason), fuel pump, & the engine & starter safety switches). 

 

I also don't do much pre-ride idling or running before I ride off to trap data as that shortens the data columns to a more user friendly length. (no big deal but it does help when looking at the data)

 

If you could I would like to see another data log in the future (after you go through all your current gasoline in the fuel tank) as I see some ignition angle numbers that don't match up to my known-good data logs. But yours are probably OK as the 2005/2006 ignition angles always look different than the later 2007 up hexheads (I just want to verify with a new data log in the future if possible)--- The knock sensor numbers look OK so it doesn't look like it is pulling a lot of spark out due to low octane knock.  

[lkraus]

Have you checked that the brakes (especially rear) are not dragging?

[PeteR1200]

Thanks D.R for the informaiton.  I am running a full tank and will verify if the calculated mpg matches the displayed, the bike is running great.  I will do another log, wot and reduced data,  I figured starting with everything turned on and then back off after that.  It took me a bit to get the Gs911-WIFI working isolated, now I know!!

 

Ikraus, I have replaced the front pads as they were close to be workout and did check the rear pads with no noticeable drag.

 

 

 

[Doctor T]

Any updates with your problem?