Warm up bike? Yes or No???

[Al st1100]

Are you kidding? You don't have to Google very deeply to find out how ECMs actually keep modulating the AFR above and below this value in function of different operating parameters.

And the goal IS to stay as lean as possible for best fuel economy. Under some conditions leanest may be 12: 1, under others maybe 17:1.

When you say as lean as possible 12:1 is not lean. when I look at lambda 1 is 14.7 to 1, 12:1 in lambda would be slightly rich and have a value of, I'm guessing of about 8 now 17:1 in lambda woulds be about -8. So when I'm loooking at fuel trims Negative munbers is subtracting fuel from the center point of 1 and + numbers are adding fuel to the center poil of 1 yes fuel ratios are always changing but at normal cruising, steady throttle 14.7 to 1 is the spot (stoich) Lamba is 1 , 17/1 would be on the lean side 12/1 would be on the rich side but under certain conditions that would be the best fuel economy but it's running richer. I don't need google but I use as a back up for others to research https://help.summitracing.com/app/answers/detail/a_id/5230/~/engine-basics---air/fuel-mixture

 

[Andrew Shadow]

I have seen a lot of flooded engines and just because it was flooded doesn't mean it creates excessive wear.

Four stroke and two stroke are two completely different animals. A flooded two stroke has to much fuel in the cylinder but it still contains the same ratio of oil to fuel, so it probably isn't any worse off. A badly flooded four stroke engine often will have so much fuel in the oil that it is like water and can no longer protect the engine and needs to be changed. That fuel got there past the rings and washed all of the oil off of the cylinder walls on its way by resulting in a lesser concentration of oil on the cylinder walls than there is supposed to be, leaving them poorly lubricated. This is no where near as serious an issue as it used to be because the engine tolerances are so much better now as are the rings.

"How is a 2 stroke engine lubricated?

By adding lubricating oil to the gas or injecting it.

2 stoke engines have a lot of gas lubricating things some as much as 50 to 1.

And without the oil that makes up the 1 they won't run for very long.

 

[Andrew Shadow]

fuel ratios are always changing but at normal cruising, steady throttle 14.7 to 1 is the spot

Based on my experience repairing fuel injection systems, I tend to agree with Al. The system was always trying to maintain 14.7:1. At that ratio the O2 sensors were neutral and not advising the need for any any modification to the fuel input. As soon as the ratio strayed from 14.7:1 the O2 sensors would detect it and report it to the ECM which would command a different fuel delivery to try to get back to a 14.7:1 ratio.

 

[Al st1100]

Four stroke and two stroke are two completely different animals. A flooded two stroke has to much fuel in the cylinder but it still contains the same ratio of oil to fuel, so it probably isn't any worse off. A badly flooded four stroke engine often will have so much fuel in the oil that it is like water and can no longer protect the engine and needs to be changed. That fuel got there past the rings and washed all of the oil off of the cylinder walls on its way by resulting in a lesser concentration of oil on the cylinder walls than there is supposed to be, leaving them poorly lubricated. This is no where near as serious an issue as it used to be because the engine tolerances are so much better now as are the rings.

By adding lubricating oil to the gas or injecting it.

And without the oil that makes up the 1 they won't run for very long.

gas and oil go thru the crankcase on older models as I stated. newer one are different , My point was is that gas does have some lubricating properties, I never said a lot
Does a 2 stroke engine have crankcase oil?


2 stroke engines use a crankcase to pressurize the air-fuel mixture before transfer to the cylinder. Unlike 4 stroke engines, they cannot be lubricated by oil contained in the crankcase and sump: lubricating oil would be swept up and burnt with the fuel.

 

[Andrew Shadow]

Unless I am not understanding what you are attempting to convey it appears to be the same scenario, so all I have to offer is the same answer.

lubricating oil would be swept up and burnt with the fuel.

Correct, in a two stroke engine the lubricating oil is burnt with the fuel. They are lubricated by the oil that is present in the fuel, or is injected, because as you stated there is no oil sump. Without that added oil the gas provides an irrelevant and insufficient level of lubrication for the engine to survive for very long.

 

[dduelin]

It is easier to just warm it up until the idle comes down. The change just isn't worth the time or effort of warming with clutch in.

No, I’m saying put it in first then start the bike and ride off. No effort involved, no waiting.

But we all have our preferences as this thread attests to.

 

[MidLife]

of course. but it [gasoline] still has some lubricating proprerties

...sure, and so does water....

Water found to be an ideal lubricant for nanomachines

Researchers from the University of Amsterdam have discovered that machines just one molecule in size move far quicker if you add a 'lubricant' to their surroundings. To their surprise, water proved to be the best lubricant by far. The research will be published on 1 September 2013 in Nature...

phys.org

.

"How is a 2 stroke engine lubricated?

.....by two stroker specific oil added to the fuel. My two strokers required premix, some modern ones have oil injection.....check what happens very abruptly as soon as the injection fails!

 

[MidLife]

.......gas does have some lubricating properties, I never said a lot....

True. Never said a lot......but......

.....unleaded gasoline has shown extreme good lubricity value......

 

[Chris09]

Trying to remember what I had for an oil injection on my 86 Johnson 110 V4, but when my fuel pump failed and a compatible one was expensive I learned that many abandoned these systems before they had problems and pre-mixed. I installed a basic one for I think a hundred dollars and pre-mixed 50:1 while some label indications on 2 stroke oil and personal accounts were that guys were mixing as low as 75:1 Never ran better before manually pre-mixing but I hate to see what happens with ethanol. 18 month old pre-mixed fuel in vented gas tank looked day one and ran great in the spring. Those days are gone.

I can't imagine the ECU on anything over 10:1 compression or that runs in excess of 6,000 rpm maintaining stoichiometric without destroying itself, there may have been some 8.5:1 economy engines that approached that but I'd have to believe that the ST ECU attempts to track along an ever fuel enriching / rpm curve at some point. As well the sensor may be sensing a combination of one rich / one lean and there's going to be a lot heat in Mr. Lean.

Gone are my [very brief] days of the JCI 8500 and Cal 1 programming, [as manufacturers have made sure of] but wouldn't it be great to get the complete set of pre-compiled plain english logical executions that went into these little black boxes, even though you can't change anything, full understanding solves a lot of problems.

 

[Larry Fine]

Never ran better before manually pre-mixing but I hate to see what happens with ethanol. 18 month old pre-mixed fuel in vented gas tank looked day one and ran great in the spring. Those days are gone.

Pure-gas.org - ethanol-free gasoline in the U.S. and Canada

Pure-gas.org is the definitive web site listing stations that sell pure gasoline in the U.S. and Canada.

www.pure-gas.org

 

[MidLife]

......12:1 is not lean when I look at lambda .....

Not comparing with Lambda = 1. Just stating that tuners seem to aim for the leanest mixture possible for a specific load (be it acceleration, deceleration, cruising, start up, warm up, etc).

Some web info if you are interested:

""""For optimum fuel economy 16-17:1 is usually best, leaner than that and the car will begin to misfire. Maximum power is usually found between 12-14:1, but this may be too lean for safety on many engines. For maximum reliability at full power, air fuel ratios from 10.5-12.5:1 are considered best, depending on the engine """"

Air Fuel Ratio Guide: How To Keep Your Engine Safe

Nothing causes engine failures more than an incorrect air fuel ratio. We show you why it happens and how to prevent it.

www.fastcar.co.uk

.

 

[MidLife]

.....full understanding solves a lot of problems....

Like....best way to bring the bike up to operating temp....maybe .............. !

 

[Catmandu2]

Some web info if you are interested:

""""For optimum fuel economy 16-17:1 is usually best, leaner than that and the car will begin to misfire. Maximum power is usually found between 12-14:1, but this may be too lean for safety on many engines. For maximum reliability at full power, air fuel ratios from 10.5-12.5:1 are considered best, depending on the engine

Did quite a bit of fuel mapping on my '04 ST13,, which has Bazzaz fuel injection. It is running great,, btw,, with better acceleration than my stocker 2012,,, but that's another story. The way that the web statement is worded is a bit confusing (at least to me),,, so just want to clarify. When I used Bazzaz to develope my two custom afr maps,,, the target ratio's were generally 13.2/1 .. I say generally,,, because Bazzaz maps allow for different ratio's at various rpm's. A richer ratio,,, say 12.6 may result in slightly better power than 13-13.2,,, but you are going to be smelling gasoline at every stop,, and super rich on startups (may foul, wet or soot plugs). Washing the cylinder walls could be more likely. Running it leaner,,, up towards the strictly theoretical "Stoick 14.7ish" is hot and dry,, and prone to misfire. You may burn up stuff,,, but until then,,, your emissions will be great (low),,, assuming you still have your catalytic's. I must have done over a dozen fuel maps for my bike,,, but settled on 2 for now. One for everyday driving,, and one for pulling out the baffles and not worrying about fuel mileage (just maximum grins). cheers,, CAt'

 

[MidLife]

Did quite a bit of fuel mapping on my '04 ST13,, which has Bazzaz fuel injection. It is running great,, btw,, with better acceleration than my stocker 2012,,, but that's another story.

Nice!

The way that the web statement is worded is a bit confusing .....

Thought your observations had same trend though.

 

[Al st1100]

.....by two stroker specific oil added to the fuel. My two strokers required premix, some modern ones have oil injection.....check what happens very abruptly as soon as the injection fails!
[/QUOTE]
ya think...my statements were about older 2 strokes, and we beat the crap out of them for years with just engine oil

 

[Al st1100]

True. Never said a lot......but......

Gasoline Lubricity

It is concluded that the lubricity of gasoline is the least well understood of all three fuels due largely to the lack of a reliable test method for measuring the lubricity of such a very volatile and contamination-sensitive material. To overcome this limitation, the development of a simple and...

www.intechopen.com

 

[Al st1100]

Not comparing with Lambda = 1. Just stating that tuners seem to aim for the leanest mixture possible for a specific load (be it acceleration, deceleration, cruising, start up, warm up, etc).

Some web info if you are interested:

""""For optimum fuel economy 16-17:1 is usually best, leaner than that and the car will begin to misfire. Maximum power is usually found between 12-14:1, but this may be too lean for safety on many engines. For maximum reliability at full power, air fuel ratios from 10.5-12.5:1 are considered best, depending on the engine """"

Air Fuel Ratio Guide: How To Keep Your Engine Safe

Nothing causes engine failures more than an incorrect air fuel ratio. We show you why it happens and how to prevent it.

www.fastcar.co.uk

.

so where is your zero point between rich and lean? /

 

[MidLife]

so where is your zero point between rich and lean? /

Every load condition has its own optimal setting (hence the "mapping"). Widen the pulse and you'll go richer or leaner if you go the other way.

For instance, under acceleration you could be at .95 and still be considered too lean for the conditions.

See CAt's post above for illustration.

Did quite a bit of fuel mapping on my '04 ST13,, ...... cheers,, CAt'

 

[acedantinne]

I don't think we should even start the engine until it's fully warmed up.

Of course, just kidding, but I don't really see the difference between starting a cold engine and easing out of the driveway.

I remember an ad for oil many years ago (I don't remember the oil) where they guarantied that the engine would never suffer an oil-related failure if you used their oil. I have NEVER heard of an oil-related failure caused by not warming up an engine before putting it in gear.

That was Quaker State oil. Reason they had some thing go real wrong with there truck oil. Engine failures.

 

[Al st1100]

Every load condition has its own optimal setting (hence the "mapping"). Widen the pulse and you'll go richer or leaner if you go the other way.

For instance, under acceleration you could be at .95 and still be considered too lean for the conditions.

See CAt's post above for illustration.

It's simple your crusing along steady speed flat land af 15/1. you come apon a steep hill now the ECM richens the fuel 12 or 13 to 1. It's not leaning out to 12/1 now on the down hill side it will lean out the ratio