General Discussion Forum

sorry skip, i had to.

skip said that EFI on dirt bikes do not change the timing and other things for weather. but now that the 09 crf450 has been released with EFI, it actually does change it to air intake temperatures. so it will make changes in different weather conditions. although i dont think it reads exhaust temperatures, like you were talking about. sorry i just had to point it out because it seems like he is never wrong and his knowledge is highly appreciated on this forum.  
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Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80

Bum Bum BAAAAAAAAAAAAAAAAAAAAAAAA!!!!!!!  

I like the fact that they sell "a tool" for adjusting ignition mapping.  
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Nobody's gonna hurt anybody. We're gonna be like little Fonzies here. And what's Fonzie like? Come on what's Fonzie like?

Hmmm... I believe what I said was that it had a Mass Air sensor, but could not make adjustments for significant changes in altitude, and other big changes (such as free-flowing exhaust), due to the fact that it doesn't operate 'closed loop' and would require a Lamda O2 sensor in order to be able to make those big adjustments..

But the Skipper has run aground on more than one occasion, so I'm ok with being wrong

I'm still waiting tobe nailed on my 2009 Honda 2-stroke prediction!!  
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Here we go again!

I'm still holding my breath!  
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Nobody's gonna hurt anybody. We're gonna be like little Fonzies here. And what's Fonzie like? Come on what's Fonzie like?

see thats the same thing i said friday. i dont think honda is done releasing all their models yet. they still havent released their street bikes and i cant find an official press release like what yamaha did.  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80

elks been searching hard to catch the skipper on something.. ELK  now you can die happy  
=====================i eat the desert and the dessert

I would nail ya to the wall on that one Skipper but I am still hoping it comes true.  

Bill H. 2000 CR250R

Honda always relases info in waves - not all at once like Yamaha.  Kind of irritating if you ask me.... I also think they are banking a little too much on the 'black scheme' - black is cool, but it's just a color - they should have taken the time to correct some of the flaws in the CRF250R.

Remember, if you will, that Honda intended to get out of the Motorcycle business back in the late 80's.  Honda's namesake and Late founder issued a Corporate Directive prior to his death committing Honda to the manufacture of motorcycles for as long as there was a place for them.  However, there has always been a feeling that Honda may not be all that keen on the MC market anymore, and builds them out of requirement - not desire.

As for the CRF450 with EFI.  Don't get too hot and bothered about it just yet... it's open loop, which means it can't self correct.  Just like honda ran stupid-lean jetting on the pilot and needle of their carb'd bikes, they will program the EFI to do the same thing, so it can still bog and flameout - it will just require a $350 digital tool instead of $25 worth of jets to fix

Random post in 2011:

HELP!  My Honda CRF450 bogs badly!!!

HondaApe

Reply from Skip:


Ape, plug the PCOMM into your ECU piggyback and change the 1k-3k pulse width to 150ms from 120MS, and then set the Base 2 Ignition map to +1 across the board and you'll be golden.

LMAO!!

I kill myself somedays ...  carry on gents  
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Here we go again!

Why couldn't they just use a USB port and give basic program pack as shareware online?  

Bill H. 2000 CR250R

lmao skip  
=====================i eat the desert and the dessert

skip thats why i posted this. it can self correct.

- PGM-FI system monitors throttle position, intake air and coolant temperatures, air pressure and gear position to accurately map fuel charge and ignition spark, significantly improving partial-throttle response and helping assure excellent rideability.  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80

Time to start your Honda aftermarket ecu business Skip.  
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Nobody's gonna hurt anybody. We're gonna be like little Fonzies here. And what's Fonzie like? Come on what's Fonzie like?

Elko,

The operative term here is MAP.  

Monitoring Throttle Position helps the system to choose which pre-defined map to use.  At low throttle positions you want the mixture a little on the lean side. At mid throttle, you want a typical 13:1 AFR.  At large throttle openings, you want a little richer mixture to help keep things cool (say 12.5:1).

Intake air and coolant temps also tie to a map, as we know cool air is denser and requires proportionally more gas, and hot engines need a little more fuel to cool them off.

Gear position (and for that matter, TPS) have been programmed into multi-map CDI's for several years now, and would not effect fueling.

But self-correct implies that the system can identify when it's running lean/rich and adjust for it.  This EFI - unless it is closed loop - can't.  You see, a closed loop system employs a Lamda sensor in the exhaust stream that measures oxides.  It can determine of the engine is running rich or lean, and instantly correct the mixute for the condition.  
Honda's design - as far as I can tell - is open loop.  It has all these sensors, but everything is based on a pre-programmed map, NOT on corrections based on a measurement of the running condition.  For example - neither a TPS map, a intake/coolant temp map, MAP instake sensor, nor a gear position sensor, would have any clue that you just added a free-flowing pipe. They would run the same mapping routines and have no clue that the motor was running on the lean side when the throttle was opened up.  
Take this a step further.  At 5,280' above sea level the system can detect a reduction in air pressure, and correct for it, but what it won't take into account is that the fuel sold at high altitude is significantly more oxegenated than fuel sold at sea level.  The result is that the map will indicate a mixture that is leaner than the conditions require.  And since there is no O2 sensor to tell the ECU that the motor is running lean, it will continue to operate based on the map - no self-corrections to the actual running condition.

I believe when the manufacturers figure out a way to build a small yet accurate Lamda sensor, we'll get a proper closed loop, self-correcting system.  Until then, this EFI - for as much of a step forward as it has the potential to be, doesn't really self-correct for all conditions yet.  It can simply choose from a handful of pre-defined maps based on some sensors, NONE of which can measure how the engine is actually running (rich/lean).

In practical terms, ask anyone running an EFI Harley up in the Rockies - they'll tell you how much they LOVE open-loop EFI  
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Here we go again!

say you put a different exhaust on and it makes the bike run lean. this would cause operating temperature to increase. also making the coolant temperature increase. so the sensor would detect this and change accordingly. right?  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80