Warm up bike? Yes or No???

Extended idling for warmup just means more time that an overly rich mixture is washing oil from the cylinder walls. Start the bike and ride gently, minimizing load.

This goes for carbureted bikes, too. I've noticed that a ton of people seem to think that chokes or enrichening circuits have to be either on or off. You taper off the choke as the bike warms up over the course of a couple of miles.

People also forget that the entire engine and drive line needs to warm up. There's always a Harley guy who spends five minutes blipping his throttle in the morning just to blast down the street on a cold transmission.
 
gummycarbs said:
Extended idling for warmup just means more time that an overly rich mixture is washing oil from the cylinder walls.
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No enriching on EFI engines (unburned fuel would damage the converter...), only fast idle...

and on my carbureted 1100 the choke is only required for firing, then to 1200rpm, once I've my gloves on and mount choke is off...
 
ST1100Y said:
No enriching on EFI engines (unburned fuel would damage the converter...), only fast idle...
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That's false. EFI with O2 sensors will initially operate in open-loop mode, ignoring the O2 sensors and using a pre-programmed fuel map. Once the engine reaches some condition, it will switch to closed loop and use the O2 sensors to lean out the mixture as much as possible.
 
ST1100Y said:
No enriching on EFI engines (unburned fuel would damage the converter...), only fast idle...

and on my carbureted 1100 the choke is only required for firing, then to 1200rpm, once I've my gloves on and mount choke is off...
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Honda’s PGMFI gives a rich mixture until coolant temp comes up to one bar. That’s why the common stuck thermostat in this bike kills mpg because the ECM gets a signal from the coolant temp sensor the engine has not warmed up.
 
To avoid issues with the thermostat, ecm, PGMFI, then would it be worth it just to allow the bike to warm up to 1-bar, and then start my travels?

Again, I just want to take care of the bike and avoid premature wear or damage that will be more costly down the road.
 
gummycarbs said:
That's false. EFI with O2 sensors will initially operate in open-loop mode, ignoring the O2 sensors and using a pre-programmed fuel map. Once the engine reaches some condition, it will switch to closed loop and use the O2 sensors to lean out the mixture as much as possible.
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I think what you mean in closed loop the O2 or fuel ratio sensor( depending on system) bring it into stoich, short for stoichiometric , 14.7 to 1?
 
dlim said:
........NO warm up.......
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Not while idling! But....

gummycarbs said:
Extended idling for warmup just means more time that an overly rich mixture is washing oil from the cylinder walls. Start the bike and ride gently, minimizing load.
Click to expand...


This is good advice here. The cylinder lubrication is poor during warm up, so best is to reduce warm up time, to cut down operating time with enriched mixture.

And the engine will warm up faster under light load than idling.
 
dlim said:
To avoid issues with the thermostat, ecm, PGMFI, then would it be worth it just to allow the bike to warm up to 1-bar, and then start my travels?

Again, I just want to take care of the bike and avoid premature wear or damage that will be more costly down the road.
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Yeah sure. Do that warm up and maybe you can get 500,000 or 600,000 miles out of it rather than 350,000 or 400,000.
 
I like to let my car get off fast idle maybe down to 1000 rpm then take off. My bike engine maybe three minutes. This has been working great for me.
 
My shifter certainly seems smoother when I let it idle while gearing up.
 
dlim said:
I hear many opposing views and opinions on this amongst people I ride with. Some claim warming up the bike (up to at least 1 bar), allows fluids and metal bearing surfaces to warm up and expand. They claim this reduces engine wear over time.

The other side of the camp claims it's not necessary, as long as you are easy on the RPM's until the bike is warm and you don't 'crack' the throttle. The motorcycle doesn't have a choke and is fuel injected so why warm up. They argue it's not dissimilar to a car engine.

What say you ST-Owners.com??? Warm up, or NO warm up???
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A. Couple of minutes say 5 min makes mine run better. At start off
 
I live in mild weather California. I give it about 30 seconds while I put my helmet chin bar down and put my gloves on. I then ride it easy until I get to one bar on the temp gauge before getting on the freeway.

If it’s frosty out in the morning, I take the slightly longer (5 minutes) route to the freeway on-ramp to get to one bar on the temp gauge.

On my carbureted Nighthawk 750, full choke to start. As the RPMs come up I adjust the choke until it’s running at about 1,000 RPMs. Then I’ll get on the road with the choke part-way on and I will take the choke off before getting on the freeway. Slightly longer route again if it’s frosty outside.
 
No need for a full warm up - get er out of the garage start it, then a quick check around the bike tires etc - helmet and gloves - double check the pockets and the idle will drop down with 1 bar showing. Get on with the ride.
 
Ever since I was a child I was always told to have the engine completely warmed up, (not just coolant) before putting under heavy loads. The way I understood the reasoning was based on tolerences inside the engine being calculated on "expanded" (operating temp) metal components. Some tolerences may be "off" due to cooler temps in the metals. With this in mind, I start the bike before gloves and helmet go on then back it out and baby it for a good 20 mins or more. Honestly I rarely put the ST under heavy loads/hard acceleration as I have another bike (MT-10) that is much better suited for that kind of riding.
Just my $.02
 
gummycarbs said:
Extended idling for warmup just means more time that an overly rich mixture is washing oil from the cylinder walls. Start the bike and ride gently, minimizing load.
Click to expand...
If there is oil on the cylinder wall doesn't that mean that the oil scaper rings( oil control rings) are not working and it's burning oil? Aren't oil control rings suppost to keep oil out of the combustion chamber? Isn't gasoling a lubricant also?
 
gummycarbs said:
That's false. EFI with O2 sensors will initially operate in open-loop mode, ignoring the O2 sensors and using a pre-programmed fuel map. Once the engine reaches some condition, it will switch to closed loop and use the O2 sensors to lean out the mixture as much as possible.
Click to expand...

Al st1100 said:
I think what you mean in closed loop the O2 or fuel ratio sensor( depending on system) bring it into stoich, short for stoichiometric , 14.7 to 1?
Click to expand...
Nope, open-loop when cold because it takes O2-sensor 2-3min to warm up to operating temperatures. So ECU ignores it in beginning. On cold-starts, ECU gives variable amount of enrichment above base-maps based upon air & coolant temps. That's because cold air won't vapourise liquid petrol and lots of it will just pass through without burning. So a little extra is needed to ensure what there's enough vapourised petrol to combust. Here's data from Bosch Motronic 3.1 ECU showing fuel-enrichment values on cold-start based upon outside air-temps. +3.1% at 66F, +7.8% at 12F and +12.5% at -27F

1695351565598.png
 
Al st1100 said:
If there is oil on the cylinder wall doesn't that mean that the oil scaper rings( oil control rings) are not working and it's burning oil? Aren't oil control rings suppost to keep oil out of the combustion chamber? Isn't gasoling a lubricant also?
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There's tiny layer of oil to lubricate rings. That's why there's cross-hatching on cylinders. Depressions of scratches hold oil and prevents rings from removing too much. There's optimum amount of valleys and angles of scratches that yields optimum oil-retention and cylinder-sealing. Too much petrol will wash this oil off and create excessive wear.

1695351910814.png

https://www.researchgate.net/figure...cross-hatch-honed-bore-surface_fig1_275558629
https://www.sciencedirect.com/science/article/abs/pii/S0301679X2100503X
https://www.researchgate.net/figure...hatch-angle-a-47-b-58-and-c-65_fig1_332688286

Modern alloy MMC cylinders (Alusil, Nikasil, Argil, etc.) has hard silicon-carbide crystals that are plateau honed for smooth rubbing surface. Then aluminium in between those crystals are etched away to leave depressions in between crystals to hold oil. Again, there's an optimum depth for this. Remove too little and surface doesn't hold enough oil. Remove too much aluminium and there's potential for crumbing of surface.

1695352338206.png

https://www.mmsonline.com/articles/new-honing-options-for-hypereutectic-aluminum-cylinder-bores
https://www.researchgate.net/public...anding_Bore_Scoring_in_Al-Si_Cylinder_Systems
https://www.yumpu.com/en/document/r...ions-for-hypereutectic-aluminum-cylinder-aera
https://issuu.com/lnengineering/docs/2020_-_bore_scoring
https://www.scribd.com/document/229492005/Nikasil-and-Alusil

Moto oils tend to have film-strength in 60,000 to 90,000psi range in the hydrodynamic wedge. Can't find any data for using petrol as lubricant, it's so inappropriate, I doubt anyone has even measured its properties in such applications. Too much petrol can leak into crankcase and dilute oil, causing major wear issues.

https://www.machinerylubrication.com/Read/30835/lubricant-film-strength
https://www.azom.com/article.aspx?ArticleID=12880
 
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When the engine's cold (overnight or longer) I start her and then don my gear. By the time I'm ready to go, the temp gauge has moved off its lowest indication. That's good enough for me.
 
On my water-cooled bikes I wait until there is some heat registered in the coolant, my VFR800 starts displaying at 34C I believe, on the ST I wait for one bar, and on my MT-10 I wait for 38C. It doesn't take long and I feel like I am being kinder to the mechanical bits. I then ride in a calm and easy manner until we all get up to normal operating temperatures, at which point anything goes. The manual for the VFR800 and the ST1300 states that "after the engine is warmed up, it is ready for riding". Of course it doesn't specify what "warmed up" means...
 
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