Anybody notice this?

So, I was involved in some "gas mileage" threads a few months back, and don't really care about mileage as long as it's better than my Camry. Around town on my 5th gen has been 25ish. I accelerate hard, running to and from school...short trips of 1-2 miles a lot.
  Last  week I was checking the bike over for my 75 mile trip to Shreveport to take an important test, and found I was wayyyy over-charging. 15-16 volts at idle. Closer examination of my VFRness installation revealed a lost bolt on the rectifier/regulator...the one you ground to. OOPS. And one the extra ground wire to that bolt had melted the connector! OUCH. Snip, snip, strip, strip, solder,solder...and back to brand new. A couple coats of liquid electrical tape, and Im at 13V at idle and almost, but not quite 15 at 5k rpm. Nice.
  So, the punch line? I have about 3k miles on this 98 since I got it in December, always get 25-30 mpg. SHreveport trip = 45mpg. Successive fillups yield 30-35 around town. I don't really care about the mileage, but this is significant. No change in riding style - the Shreveport trip was highway, but I have done shorter trips producing only 30mpg highway. Until fixing this electrical gremlin...
  Anybody else have anything like this go on?

  P.S. does Tightwad make a 7th gen VFRness yet? Just curious...

I suspect it has more to do with a change in gas blend or riding style.

I doubt it would be much about the voltage and more about a weak plug or coil or something. I'd go through and check the bike over.

[image: View Post]YoshiHNS, on 23 June 2010 - 01:30 PM, said:

I doubt it would be much about the voltage and more about a weak plug or coil or something. I'd go through and check the bike over.

Well, 3 tanks later and still consistently higher mpg. Only change: fixed wiring on vfrness, resulting in better/more consistent voltages. Maybe my CDI box (does the 5th gen  call it a CDI? or is it a CPU?) was funny due to the voltages? My 90 model fried 3 CDI boxes...r/r problems galore. Wish Josh had made the VFRness back when...

[image: View Post]Jmmymc750, on 23 June 2010 - 12:49 PM, said:

So, I was involved in some "gas mileage" threads a few months back, and don't really care about mileage as long as it's better than my Camry. Around town on my 5th gen has been 25ish. I accelerate hard, running to and from school...short trips of 1-2 miles a lot.
  Last  week I was checking the bike over for my 75 mile trip to Shreveport to take an important test, and found I was wayyyy over-charging. 15-16 volts at idle. Closer examination of my VFRness installation revealed a lost bolt on the rectifier/regulator...the one you ground to. OOPS. And one the extra ground wire to that bolt had melted the connector! OUCH. Snip, snip, strip, strip, solder,solder...and back to brand new. A couple coats of liquid electrical tape, and Im at 13V at idle and almost, but not quite 15 at 5k rpm. Nice.
  So, the punch line? I have about 3k miles on this 98 since I got it in December, always get 25-30 mpg. SHreveport trip = 45mpg. Successive fillups yield 30-35 around town. I don't really care about the mileage, but this is significant. No change in riding style - the Shreveport trip was highway, but I have done shorter trips producing only 30mpg highway. Until fixing this electrical gremlin...
  Anybody else have anything like this go on?

  P.S. does Tightwad make a 7th gen VFRness yet? Just curious...

Right now, this time of year, you'll get your best fuel milege with FI, FI motocycles drink when it gets colder


But your mileges sound normal for that bike

[image: View Post]Jmmymc750, on 23 June 2010 - 12:49 PM, said:

...short trips of 1-2 miles a lot...

I'm guessing on these trips that you never get up to normal operating temperature and it stays in a computer mandated rich condition, hence the low mileage.  During summer temps, this is probably not as big a factor.

[image: View Post]Earthshake, on 25 June 2010 - 08:35 PM, said:

[image: View Post]Jmmymc750, on 23 June 2010 - 12:49 PM, said:

...short trips of 1-2 miles a lot...

I'm guessing on these trips that you never get up to normal operating temperature and it stays in a computer mandated rich condition, hence the low mileage.  During summer temps, this is probably not as big a factor.
I thought about this...but for weeks and weeks it has been in the 80s by 8 am...and no change in mileage. Until this fix...

The 5thgen does alter the fuel injection when the feeding voltage is too low.
Whether it increases or decreases the consumption I don't know.
One could assume it increases.
You should add your 98 to your profile description on the left.