Fuel economy is terrible!!

The Dark Shadow · May 10, 2023

Andrew Shadow said:
That is to long to get to the first bar at that ambient air temperature. It should happen within about a minute. I think that your thermostat is sticking.

Yes... It is seeming likely. I ordered a new t stat and o ring, plus 2x water joint o rings.

Fingers crossed that this 86 dollar parts fee (1000 dollar labour fee!! lol) will fix my issue.

Andrew Shadow · May 10, 2023

Take the opportunity to do a good cooling system flush as well. Buy the Honda Type 2 prediluted antifreeze from a Honda automotive dealer- much cheaper than the Honda motorcycle dealer.

Igofar · May 10, 2023

Be sure to clean/remove the black paint from the insides of both radiator pipes, as it will work through the system and clog stuff up.
If your T-stat isn’t completely stuck open, your going to find scrape marks where it is dragging on the corrosion on the body etc.
When it’s stuck open, the ECU thinks the bike is not warmed up yet, and keeps throwing more fuel into the mix.

Catmandu2 · May 10, 2023

The Dark Shadow said:
BTW, what state/province/country and what elevation are you in...? I read that altitude and heat make a big difference on mileage for this bike.

Ontario, Canada,, about 100m above sea level,,, I think. I ride between 0c and +35c. This bike does love the cool weather,, but also starts to leak,,, cheers,,, CAt'

The Dark Shadow · May 10, 2023

Catmandu2 said:
Ontario, Canada,, about 100m above sea level,,, I think. I ride between 0c and +35c. This bike does love the cool weather,, but also starts to leak,,, cheers,,, CAt'

What starts to leak...?

Kevcules · May 10, 2023

The Dark Shadow said:
What starts to leak...?

"Coolant" from the many small hose clamps near and around the thermostat. The ST is well known for this.

Catmandu2 · May 10, 2023

The Dark Shadow said:
What starts to leak...?

I wouldn't get too worried about it. My 2004 needs those clamps snugged up every 3 or 4 years,, as they get looser with each heat cycle. The aluminum spigots shrink smaller in cold weather than the oem steel band clamps do,,, so at 0 to 8c approx, gradually,,, those joining's start to seep. My 2012 has a lot less heat cycles on it,, and it is still dry in cold temps. Do you store in a heated garage ?? You may not have any seeps for a long time,,, cheers,, CAt'

The Dark Shadow · May 10, 2023

Okay, so I'm coming to the end of my questions... FWIW, I've decided to change the thermostat. The coolant temperature sensor is only 50 bucks, so I wonder about its longevity and if people would recommend change it also, or not necessary...

Thanks again everyone!!

Igofar · May 10, 2023

You’d be wasting money.
I’ve never even see one fail.

Andrew Shadow · May 10, 2023

The Dark Shadow said:
Okay, so I'm coming to the end of my questions... FWIW, I've decided to change the thermostat. The coolant temperature sensor is only 50 bucks, so I wonder about its longevity and if people would recommend change it also, or not necessary...

Thanks again everyone!!

I only ever remember hearing of one causing faulty readings and that was because it was full of crud, not because it was defective. It was removed, cleaned up and reinstalled, and it worked properly after.

I wouldn't replace it without a good reason showing itself.

Mikedo · May 11, 2023

The Dark Shadow said:
Okay, so I'm coming to the end of my questions... FWIW, I've decided to change the thermostat. The coolant temperature sensor is only 50 bucks, so I wonder about its longevity and if people would recommend change it also, or not necessary...

Thanks again everyone!!

Agree with Andrew Shadow, the type II coolant from the Honda car dealer works fine. Designed for aluminum block engine. My dealer was feeling gracious and just gave it to me as it was an open jug and it is low silicate.

Regarding the sensor I'd go with Igofar and not change if if working. He says change everything else (brake fluid every 5 years I think he said

, clutch too

. So if it's a no change on that I'd take that to the bank.

Igofar · May 11, 2023

Brake fluid flush once a YEAR regardless of mileage, and clutch about every 6 months, if you don't want to replace your clutch slave cylinder :rofl1:

Your every 5 year comment has me reaching for valium :rofl1:

Bright Rider · May 11, 2023

Andrew Shadow said:
That is to long to get to the first bar at that ambient air temperature. It should happen within about a minute. I think that your thermostat is sticking.

Looks like I may be suffering the same issue and didn't know it due to the warm temperatures I live in here in NC. I haven't timed it yet but seems like 2 - 3 minutes to warm up to one bar at 20 degrees C. Fuel mileage seems ok though. The bike is only 8 years old with about 42k on it. Do the thermostats normally go out this soon?

Andrew Shadow · May 11, 2023

Bright Rider said:
Do the thermostats normally go out this soon?

Depends on the model year and whether or not the thermostat has been replaced.

Older model years suffered from paint over-spray on the inside of the radiator hose fittings. This paint is said to come loose and the resulting chips find its way to the thermostat where it causes binding and failure. Once the thermostat has been replaced and the paint residue flushed out, normal life expectancy of the thermostat is restored. Later model years had this taken care of at the factory and suffer normal thermostat failure ratios inline with other liquid cooled engines.

I don't know where the pre and post model year break-point is for this condition.

Fawlty · May 12, 2023

Bright Rider said:
Looks like I may be suffering the same issue and didn't know it due to the warm temperatures I live in here in NC. I haven't timed it yet but seems like 2 - 3 minutes to warm up to one bar at 20 degrees C. Fuel mileage seems ok though. The bike is only 8 years old with about 42k on it. Do the thermostats normally go out this soon?

If your fuel consumption is good I wouldn't worry too much about 2-3 minutes. On start up from cold, hold your hand on the radiator. It should remain cool until the stat. starts to open. If there are signs of heat almost immediately investigate further.

Bright Rider · May 12, 2023

Andrew Shadow said:
Depends on the model year and whether or not the thermostat has been replaced.

Older model years suffered from paint over-spray on the inside of the radiator hose fittings. This paint is said to come loose and the resulting chips find its way to the thermostat where it causes binding and failure. Once the thermostat has been replaced and the paint residue flushed out, normal life expectancy of the thermostat is restored. Later model years had this taken care of at the factory and suffer normal thermostat failure ratios inline with other liquid cooled engines.

I don't know where the pre and post model year break-point is for this condition.

Thanks. As my bike is one of the newer ones hopefully they took care of the paint in the hoses at the factory. I'll look into this long warm up time further then before I assume the thermostat needs changing.

Bright Rider · May 12, 2023

Fawlty said:
If your fuel consumption is good I wouldn't worry too much about 2-3 minutes. On start up from cold, hold your hand on the radiator. It should remain cool until the stat. starts to open. If there are signs of heat almost immediately investigate further.

Thanks for the tip. My mileage seems to be in line with normal for this bike, but I'll definitely do this to see what I find.

Igofar · May 12, 2023

Bright Rider said:
Thanks. As my bike is one of the newer ones hopefully they took care of the paint in the hoses at the factory. I'll look into this long warm up time further then before I assume the thermostat needs changing.

I'd check for paint

I'm finding paint in even the new 2016 crate bikes.

Bright Rider · May 12, 2023

Igofar said:
I'd check for paint
I'm finding paint in even the new 2016 crate bikes.

Wow. That is surprising. Thank you for letting me know.

The Dark Shadow · May 24, 2023

Update...

Had the thermostat changed. No difference. Original thermostat was not stuck.

My motorbike takes 2min15sec to get to one bar (this was at ambient temperature showing 18C), 2min45sec to get to 2 bars, and 4min25sec to get to 3 bars on the temperature gauge.

The bike "choke" idle (cold idle) is about 2000rpm, then goes down to 1000rpm when warmed fully.

Can a too-rich mixture keep the motorbike cooler (and hence warm up more slowly)...??

The live data read-out I had performed showed all sensors normal and "within spec", but one thing that caught my attention was the O2 sensors showing different voltages (more than 20% difference). First sensor showing .449v, O2 sensor B showing .566v. I have no idea if this is standard or irregular. More knowledge is welcome if anyone has knowledge to share.

There were 2 error codes, but these seem likely to have occurred from the throttle body vacuum check that I had performed.

2-1 Map sensor no vacuum.
9-2 IAT sensor voltage high. (Would this error code also be due to vacuum check of the throttle bodies...??)

My most recent fuel economy check (distance corrected via GPS tracker) is 14.8km/l, or 34.81 US mpg. This is 85 percent highway driving anywhere from 70kph to 120kph.

Perhaps fuel and cold, damp, and salty air environment here just make this bike a gas pig on the east coast... I just saw a car specialist on youtube mention he was getting 36mpg from his Toyota Matrix on the highway at 70mph. I find it hard to believe that this 1.261 litre engine motorcycle can't even beat a friggin Toyota Matrix for gas mileage...

I'm hoping to go on a road trip soon, and I don't want to have to refuel after only 350km... Seems silly, since every review I read about this bike stated one of its advantages is you can drive for 450to500km on a tank...