Questions.....

[mave2911]

I have a couple of quick questions that are making me ponder.

Firstly, the easy one. I have a Dunlop Sportmax GPR-100 rear tyre. Now this tyre was fitted by the previous owner and since then has done in the vacinity of 14000kms. Now, unfortunately because I ride 120kms a day just going to and from work, I do a lot of straight riding.

The tread depth in the middle of this tyre is approx. 2mm and I'm wondering how many more kilometres I might get out of them.

Does anyone know the tread depth on a new tyre?

Anyway, the second question regards fuel economy or lack thereof.

My fuel economy is seemingly in slow decline. I was getting 19kms+ per litre, and my last tank was 17kms/L.

Now, I'm wondering if anything is wrong, or could be corrected. I've had the bike for 5mths and 11000kms. (33000kms on the clock) I've done 2 oil changes, using Motul 7100 full synthetic, have a K&N airfilter, Iridium plugs etc.

So, the easiest things to consider are:
a) I'm 'getting up it' more as I'm so familiar with it now. (accelerating harder from the lights)
b) The SpeedoHealer has stuffed something up. (I have considered the correction of speedo error has obviously had some numerical impact, but I've lost more range than I think this explains)
c) Ambient temperature. I rode to work this morning at 0400and it was 1°c, so I'm wondering if as it's slowly coming toward Winter, maybe that might explain it? (19kms+/L was toward the end of summer)

Do you who live in Winter climes see a dramatic difference in fuel economy?

On my next days off, I'm going to pull the battery to allow the ECU to recalibrate and whilst I'm at it, I'll check the air filter. (6000kms old, but highway only, so no/little dust)

Anyway, I'm looking for suggestions, if any avail themselves.

Cheers,
Rick

 

[stink989]

At a guess the air filter should be fine. Mine is fine and it's got over 35,000 on it just a little bit in it will replace at 40,000km. the bike is probably due for a throttle body sync that will make an improvement to economy and the overall smoothness of the bike. You are most likely giving it a bit more throttle then when you first got it and that obviously will greatly reduce the economy.

 

[TownsendsFJR1300]

+1 on the throttle sync.

I also have a Speedohealer which corrects the speeometer but to my understanding, will change how correct the odometer is, so there may be some # differences there..

I've noticed on mine, if I ride fairly aggressivly, my mileage drops to the low 40's. Taking it easy, about 48MPG mostly around town, occassionally up to 70MPH..

If your constantly riding at higher speeds (highway) the mileage will drop some. Check the air pressure in your tires too, it will help to keep them inflated on the higher end for MPG...

If you have Seafoam available or some sort of fuel system cleaner, it can only help. Get something known to work well. Yamaha Marine makes "Ring Free" which is an excellent product for the entire fuel system and cleans the top end/rings, etc of carbon deposites. Dirty injectors, sticky rings, etc won't help fuel economy...

You may want to check your wheels/brakes for excessive dragging. The fronts especially, with time tend to drag (hurting mileage). There are numerous threads on the subject. Yamaha does recommend replacing the caliber brake seals every TWO YEARS...

 

[ChevyFazer]

You mileage decrease is most likely 75% speedo healer 25% you being used to the bike and riding it like so just not realizing it anymore.

What ever percentage you dropped your speedo you odo will also drop so say if you dropped it 7% your odo will run 7% slower as well so if it's not counting off as many miles as what you are actually riding then it will effect your number.

You could do some math and add the percentage lost back to your miles and that will give you an accurate number

 

[callmegandhi]

Check your spark plugs.

 

[FinalImpact]

If that K&N filter is over loaded with oil you can bet its not going to flow as well as paper given the same amount of surface area being exposed.

I'd clean it and oil way less.

Do they add ethanol to your fuel there? Here is an Auto article showing a LOOOOOOOOSS of MPGs (FED's how is this a good thing?????) on an SUV.

http://www.consumerreports.org/cro/cars/new-cars/news/ethanol/overview/index.htm

Excerpt. . . "When running on E85 there was no significant change in acceleration. Fuel economy, however, dropped across the board. In highway driving, gas mileage decreased from 21 to 15 mpg; in city driving, it dropped from 9 to 7 mpg. You could expect a similar decrease in gas mileage in any current FFV. "


Lastly - if you ride more than you did and they are shorter trips at lower speeds, its likely the MPGs will drop. When we do day rides and burn a couple tanks up in a day Rippin on it, I get 48 to 50 mpg. But riding in town to work in stop and go I get 40-42 because I'm idle more often and in lower gears more often. It all adds up!

 

[mave2911]

What ever percentage you dropped your speedo you odo will also drop so say if you dropped it 7% your odo will run 7% slower as well so if it's not counting off as many miles as what you are actually riding then it will effect your number.

You could do some math and add the percentage lost back to your miles and that will give you an accurate number

I dropped the speedo by roughly 3.5% to give me a compromise between speedo and odometer accuracy, this equates to only 10kms to 12kms of the 50kms+ I seem to be missing per tank.

The Iridiums are only 7000kms old, and the bike doesn't sound or act like it's missing. (no apparent loss of power)

Cheers,
Rick

 

[mave2911]

If that K&N filter is over loaded with oil you can bet its not going to flow as well as paper given the same amount of surface area being exposed.

Still is as oiled by the factory - I just checked it, and fitted it without extra oil)

Do they add ethanol to your fuel there?

Thankfully, the only fuel with ethanol is labelled ethanol - the 98RON I use is straight petrol.

Lastly - if you ride more than you did and they are shorter trips at lower speeds, its likely the MPGs will drop. When we do day rides and burn a couple tanks up in a day Rippin on it, I get 48 to 50 mpg. But riding in town to work in stop and go I get 40-42 because I'm idle more often and in lower gears more often. It all adds up!

My bike is my commuter to get to work - I ride 115kms a day. That's 3 days per tank.

It makes tracking economy very easy as most of the variables are removed. (same way, same time etc)

As I said, it has been slowly decreasing - it WAS 19+, then 18.5, then 18, then 17.5, now 17....

Even though cooler air has more oxygen, so thus for the same volume of air, you get more power and a more complete combustion (and I've argued that fact on that other forum), many, many people said this was drastically offset by the increased wind resistance.

Maybe this is proof of their claims.

Coming into summer, if that's true, I should see a increase of fuel economy as the air thins out.

We'll see. (nothing else is jumping out at me, but I appreciate the advice about the brake seals - even a tiny bit of added drag could account for a 10% decrease in fuel efficiency)

Cheers,
Rick

 

[pookamatic]

Don't know what you're talking about... it's approaching SUMMERTIME.

I have seen an MPG drop with every car I've ever owned in the winter. I have come to a few explanations for this. More O2 = more power, more wind resistance, reduced tire pressure as temperature drops (and reduced checking because it's cold outside), and the biggest I guess is, time it takes to reach operating temperature... they just don't run efficiently until at operating temp. So not only are you letting it idle longer, you're doing so when the engine burning fuel in an inefficient manner.

For cars, but the same principle.
http://alternativefuels.about.com/od/environmentalimpact/a/winterfuelecon.htm

If you add it all up, plus your comfort with the right hand, I'd say it sounds normal.

 

[pookamatic]

Don't know what you're talking about... it's approaching SUMMERTIME.

I have seen an MPG drop with every car I've ever owned in the winter. I have come to a few explanations for this. More O2 = more power, more wind resistance, reduced tire pressure as temperature drops (and reduced checking because it's cold outside), and the biggest I guess is, time it takes to reach operating temperature... they just don't run efficiently until at operating temp. So not only are you letting it idle longer, you're doing so when the engine burning fuel in an inefficient manner.

For cars, but the same principle.
http://alternativefuels.about.com/od/environmentalimpact/a/winterfuelecon.htm

 

[TownsendsFJR1300]

I had to rebuild the front brake calibers in my 04 FJR after 5-6 years, the pistons were not retracting and you could feel the fronts dragging as you pushed the bke about the garage. Spinning the front tire while in the air, maybe 1/4 turn... After the new seals were in, 2+ full turns (same amount of spinning force), very big difference.

My 07 FZ calibers are the same as the FJR. I've cleaned and greased them (brake piston specific grease- [ame=http://www.amazon.com/Permatex-24110-Caliper-Brush-Top-Bottle/dp/B000HBNV6W]Amazon.com: Permatex 24110 Ultra Disc Brake Caliper Lube, 8 oz Brush-Top Bottle: Automotive[/ame] ) which helped alot. Next time, they get new seals..

You can check them by either free spinning by hand or go for a ride, stop with the rear brake only and touch the front rotors.. They should be room temp or close to it. If their hot, you have problems and the calibers need attention....

The above information is directed towards the FOUR PISTON pots, I don't know how well the earlier TWO piston pots are for dragging, etc...

 

[FinalImpact]

I guess it comes down to "how far will you let it go before changing something?"

My hit list is basically covered here:

• Tire pressure
• Caliper drag
• Fuel quality
• Air filter is too restrictive (factory lube or not)
• Rear wheel alignment
• Chain maintenance
• Driving style
• Engine oil wrong grade
• Weak ignition system is creating an incomplete combustion
• CO2 sensor is whacked and its running to rich
• CAT is plugged

Unlikely:

• Timing chains stretch and could retard the cam timing. This hurts MPG and performance but is unlikely.
• Left the parachute deployed / new riding gear has excess drag?

 

[mave2911]

I guess it comes down to "how far will you let it go before changing something?"

My hit list is basically covered here:

• Tire pressure
• Caliper drag
• Fuel quality
• Air filter is too restrictive (factory lube or not)
• Rear wheel alignment
• Chain maintenance
• Driving style
• Engine oil wrong grade
• Weak ignition system is creating an incomplete combustion
• CO2 sensor is whacked and its running to rich
• CAT is plugged

Unlikely:

• Timing chains stretch and could retard the cam timing. This hurts MPG and performance but is unlikely.
• Left the parachute deployed / new riding gear has excess drag?

Ok, I'll address your suggestions.

Tire pressure - perfect for my weight - F35/R39.
Caliper drag - Possibly, going to check next couple of days.
Fuel quality - Always 98RON, and always from the same servo.
Air filter is too restrictive (factory lube or not) - Doubt it as it seemed fine when fitted, but will check next couple of days
Rear wheel alignment - perfect
Chain maintenance - Use Maxima chain wax every two tanks (600 - 700kms)
Driving style - Maybe, I've tried being deliberated easy on the throttle with little result.
Engine oil wrong grade - Motul 7100 10W30 full synthetic, changed every 5000kms
Weak ignition system is creating an incomplete combustion - Possibly, and this includes Iridiums which some have had fail decreasing fuel economy.
O2 sensor is whacked and its running to rich - no such thing on 2005 model
CAT is plugged - Don't think so, although I can't speak for the previous owner, I only ever use 98RON, so I doubt it.
Left the parachute deployed / new riding gear has excess drag? - No change in riding attire.

Cheers,
Rick