There's no smell of fuel nor are there any stains on the ground where it's parked, so most likely not the culprit.
However, the odometer it a thought. Since we know the BMW speedos are always way off, mine shows almost 10mph higher than actual speed when I'm on the highway...so 75mph is actually closer to 65mph, which means the odometer would be rounding up by at least 10-15%. That means that if the odometer shows 100 miles for four gallons used then in reality it was 90 miles and then my 25mpg becomes more like 21-23mpg.
Bad to worse!
flars has a good diagnostic thought there though.
Right. My speedo is wildly optimistic, getting worse as the needle moves further into death-defying numbers.
But as you say the odo and speedo in 1990's are driven by the same cable, both should be off the same direction.
Or the odo could be independently broken and just not ticking over when it should.
Do you have a GPS?
A fuel leak is definitely worth checking out. You should smell it, but, you know, you might not, and on a hot day it may never reach the ground.
The real reason for my call is to mention that there are two other sensors that can fail and force the motronic out of closed loop - there is an air temperature sensor poked into the middle of the air filter, and there is an oil temperature sensor. The shop should be able to read the diagnostic codes (after a warm-up) directly pointing to these.
A thought occurs. My fuel cap hadn't set properly one tank Andover the course of sitting a couple of days I only got 110 miles out of the tank instead do 200. Seals not fitting on the fuel cover would be similar.
When I get lousy mileage, the problem is always in my right wrist. :stick
[QUOTE=wineguyd;888925] ..... Since we know the BMW speedos are always way off, mine shows almost 10mph higher than actual speed when I'm on the highway...so 75mph is actually closer to 65mph, which means the odometer would be rounding up by at least 10-15%. .....
Bad to worse![/QUOTE]
BMW moto speedometers are usually optimistic (not the authority speedos). However, the odometers are usually accurate. Simple enough to check against a GPS or against an interstate highway run with mile markers. Some tires, not OEM, could have a slightly different circumference which could cause a slight variance in the odometer.
[QUOTE=Roger 04 RT;888583]That's really low.
What coding plug is installed?
Do you have any add-ons like a Power Commander or Techlusion?
This is a shot from this morning, does the code plug pink color mean anything? Are these plugs prone to failure?
[QUOTE=wineguyd;888957]This is a shot from this morning, does the code plug pink color mean anything? Are these plugs prone to failure?[/QUOTE]
No, no more prone to failure than any other piece of wire.
(dives into a pile of papers, comes up with single sheet, reads...)
I may have to beg for help here for a 100% righteous answer but you will probably be satisfied that pink is the oem plug for the R bike.
I believe that Pink takes both 87 and 87a to ground (30) which tells the Motronic that (87) there is a catalytic converter or in other words to expect an O2 sensor providing closed loop, and (87a) you have "R/GS" intake tubes or cam timing - probably provides a different spark advance curve or possibly an accellerator pump function. The longer and smaller diameter intakes supposedly improve the responsiveness of the engine at the expense (possibly) of top end output.
So yellow for S/RS/RT and pink for R/GS.
...in the US.
Might check your owner's manual too, I think at least one of the mini fuses is not supposed to be blue.
[QUOTE=tommcgee;888938]When I get lousy mileage, the problem is always in my right wrist. :stick[/QUOTE]
Ah yes Twisted Wrist Syndrome, caused by abnormal pelvic tilt.
Conventional treatment is to excise the excess money which has accumulated in the area near the left buttock, reducing the pelvic tilt. Usually this will provide temporary relief from twisted wrist.
Several years ago my 95 R1100RS dropped from mid/upper 40's to low 30's. I remembered reading something years prior that a bad O2 sensor could cause the issue. I replaced the O2 sensor and the mileage went back to normal.
This is a shot from this morning, does the code plug pink color mean anything? Are these plugs prone to failure?[/QUOTE]
As others have said, you have the correct coding plug for your motorcycle. So before jumping to an O2 sensor, which is looking like the problem, you could pull fuse 5 for 15 minutes to reset the Motronic and then check your mileage again.
You could also remove the coding plug and put in a jumper from 30-87a, causing it to ignore the O2, reset and check mileage.
If the O2 sensor is bad causing your bike to run rich, you might find that with the pink plug and a working O2 sensor, that you don't like the performance as well, since the engine will then be running a lot leaner.
Take a step at a time and you'll get a good compromise.
Ok, brought it into Bergen BMW this morning and spelled out the issue for the service agent...his response was "I wouldn't expect better mileage than that from that model and year". When I pointed out that the bike was getting 35mpg when it came in for the service and left getting 25 mpg he agreed to get a mechanic to take it for a test ride. The mechanic came back saying he felt some sort of resistance and took the bike in the shop to run a few tests, he then came back telling me he believed the front calipers we not completely releasing and that I've been riding with friction which could explain the lowered mpg. With no ride home I could not leave the bike and made an appointment to bring it back next week.
They wheeled the bike out and...it wouldn't start! What ever they did in their test must have caused it so now they had no choice but to give me a ride home...BUT...not before telling me I'm going to be charged a minimum of $100 for diagnostic labor and whatever parts might be necessary. I'll fight with them later about the fact that they had just replaced the front brake master cylinder in that service as well as flushed and bled the brake system.
On another note, while I was there I went to the parts department to inquire about the part numbers for the clock module and mount, once he had it on the screen I asked him for the part numbers because I wanted to first see if I could find a used one online. I was flabbergasted that the agent looked me in the face and said he wouldn't give out the part numbers because I was not buying it from them. I have always gone to the parts departments of all the vehicles I've owned to get numbers to look for used and have never been told I could not have the numbers. Is this standard operating procedure with BMW or just this dealership?
WOW! You need a better service organization.
If the caliper was dragging enough to effect mileage to that degree I believe the rotor would have gotten very hot. On the centerstand you should be able to tell.
And as for it going in running and coming out non-OP I think the dealer bears some responsibility.
For parts go to maxbmw.com. You'll find the parts.
Always go for the basics. Any complaint about fuel economy starts with tire pressures, alignment, rolling resistance and the list of basics can keep you occupied with substantial time before you worry about coding plugs and sensors. My brother drove sixty miles with the park brake engaged on my truck. His first complaint was fuel economy and my comment was he deserved to pay for it because he didn't notice it.
Lastly, mechanics/technicians always are the first ones to be blamed when a new, unforeseen problem pops up by sheer coincidence. I built an engine for a track hoe and within twenty minutes of going to work, the main hydraulic hose popped. The customer was absolutely convinced it was because of my engine.
Ok. Um, I'm going to ignore the alarm bells going off in my head about it not starting after a tech took a test ride.
I'm going to focus on the idea that the brakes are stuck on.
This is entirely possible.
The age of the bike is about right for the original rubber brake hoses to be swollen and broken down.
As I probably mentioned, since I mention it in nearly every thread, you should change out the rubber brake hoses in favor of stainless / teflon like the ones I got from Spiegler.
This is a safety issue, I'm not just bragging about my ss brake lines.
On my RT the line going to the right front caliper split - while I was backing out of a parking spot.
It also "locked" - I had to loosen the bleeder relieve the pressure so I could push it around.
So between the split and the piston the hose was swollen shut.
I replaced it with an OEM part. Then I discovered that I could NOT bleed air out of the left caliper.
The left hose was swollen shut as well.
Now the factor making this happen is just age, not mileage, so even as low miles as you have this is probably an issue.