The CRF250L Owners thread

[MentalGuru]

Originally Posted by toddol1971

I'm sorry to hear that. Its nice that you said that, cause to be honest I thought you seemed a little easily provoked in past posts. I didnt judge you though cause I figured you had your reasons. Not the same problems as you but I know what you mean by, " You just have to put up with me" I get aggrivated pretty easily. I have spinal stenosis, 5 bulged discs and nerve damage. I'm in pain all the time and sometimes I just cant/dont want to deal with any crap. GOD bless you and I'll pray for you.

Maybe this will help. Here's some background...

4 level neck fusion, 3 level lower back fusion, every disc degenerated, 4 are bulging, 2 heart stents, a heart arthmia, 3 episodes of acute brain trama, 20+ concussions, a brain tumor and more...

I'm screwed up in the head and admit it.
Sometimes I'm an idiot other times a savant, Probably both soon...

[MentalGuru]

Originally Posted by hrcs90

Honda's PGM-FI doesn't use OBD codes like the car world like you would expect, but a more Honda style. You can pull codes if needed through the RED DLC plug on the bike, by jumping the Brown and Green wires together or purchase Honda special tool "SCS connector". Make the connection and then turn the main switch on and count the MIL blinks.

The flywheel has notched or raised sections on the flywheel to determine crank position and thus injector or ignition timing.

The injector only needs to squirt every other revolution. It needs a cam sensor or fancy programing do do this.

This system is very close to a pre 0BD2 system but not as advanced. It is very simular to Dodges system they used on early 4 cylinder MPI cars.

[NJ-Brett]

If you change things like intake, exhaust, or bore size, you have to change the amount of fuel going into the motor.
Most FI mixture corrections do not add a lot of power, but give better response, less surging, eliminate backfires, make the motor run cooler, but do not add a lot of power.

Some systems like what is on Harley's are set really lean (no cats to clean things up) and you can not do much without having problems.
Bikes with cats seem to be able to run richer and deal with some changes ok, my TU250 does.

And I do not think any system on bikes is anything like anything ever used on a car, cars were always wideband systems I think, even the early ones, while there are no wideband systems on bikes that I know of.

The systems in use on bikes are simple carb replacement systems using maps to set the mixture, with very limited input from the oxy sensor.

Originally Posted by toddol1971

wouldnt it just be easier, or at least about the same amount of money in the end to just put a bigger jug on it, or overbore to get the added power. You know nrfd. You get more gain for the same money.

[itrack]

Originally Posted by toddol1971

wouldnt it just be easier, or at least about the same amount of money in the end to just put a bigger jug on it, or overbore to get the added power. You know nrfd. You get more gain for the same money.

Sure, but I would like an open source ECU and a big bore.

[NJ-Brett]

Even some systems on cars would pulse the injectors with a closed intake valve, the mixture just hangs around before being sucked in.
Some bikes must do that as there are no cam position sensors and there is nothing to tell between TDC on the power stroke or the exhaust stroke.

Any thumper without a cam position sensor would HAVE to do this.

Originally Posted by MentalGuru

The injector only needs to squirt every other revolution. It needs a cam sensor or fancy programing do do this.

This system is very close to a pre 0BD2 system but not as advanced. It is very simular to Dodges system they used on early 4 cylinder MPI cars.

[Ed@Ford]

[QUOTE=hrcs90;20593436]Honda's PGM-FI doesn't use OBD codes like the car world like you would expect, but a more Honda style. You can pull codes if needed through the RED DLC plug on the bike, by jumping the Brown and Green wires together or purchase Honda special tool "SCS connector". Make the connection and then turn the main switch on and count the MIL blinks.


So, are you pretty convinced Honda does not use the standard OBDII 4 digit codes on production bikes? If so, that means we not only need a way to read the MIL (Malfunction Indicator Light ) blinks....but also a "dictionary" of the code # and their meaning...........

[MentalGuru]

Originally Posted by NJ-Brett

Even some systems on cars would pulse the injectors with a closed intake valve, the mixture just hangs around before being sucked in.
Some bikes must do that as there are no cam position sensors and there is nothing to tell between TDC on the power stroke or the exhaust stroke.

Any thumper without a cam position sensor would HAVE to do this.

The computer can be programed to sense when the combustion stroke happens by monitering the increase in crankshaft speed. With the proper software it is possible to fire the injector at the corect time with only a crank sensor. Some cars do this when the cam sensor fails so they cam still run in limp in mode...

[Krono]

Originally Posted by Ed@Ford

Heres the deal on two O2 sensors on a CRF. Go to the www dot rickramsey dot net web page and look in the introduction of the CRF250L file. One O2 sensor is in the exhaust port on the cylinder head. It looks at O2 level in the exhaust gas. The other sits on the rocker cover box and it looks at O2 in the fresh air that is pumped into the exhaust flow. I do not know if either sensor is heated, or if either is a "wide ratio" sensor. Some of this can be "guessed" if the wiring harness pinout for these sensors are are known. However, since the air induction sensor is looking at fresh air, I'd guess that is a wide ratio sensor. Based on past experience, this seems like an expensive solution to control the metering of air pumped into the exhaust to control hydrocarbon emissions. I am unaware of this method being used on modern engine emission management systems.....but maybe someone out there is more up-to-date on such methods.

There's only one O2 sensor, and thus at the exhaust port.
The title is a little confusing where it's placed, though ...



L

[Jinksy]

If I change the gear ratio from 14/40 to 13/43 will this give me better performance off the line?

[MentalGuru]

Originally Posted by Jinksy

If I change the gear ratio from 14/40 to 13/43 will this give me better performance off the line?

Yes...

[Krono]

About air induction, after having corcked it and disconnected the O2 sensor, following BDSB suggestions here http://bestdualsportbikes.com/dual-s...honda-crf250l/ and installed a dBkiller of my own, i had many stalling problems. That was cured by re-plugging the secondary air system and setting the first EJK parameter to 0, what got me rid of backfires too. Replugged also the O2 sensor, as i was there.

Doesn't seems logical, since i probably leaned at idle, but that's what experimentation concluded in my case.

Whatever .. i will try to experiment more with teh EJK setting (which you can emulate here http://www.electronicjetkit.com/demos/HPcurve.swf press mode, then + or -)

L

[Krono]

Originally Posted by Ed@Ford

Soooo you're telling me "AI O2 sensor" really means " Air Induction Actuator Valve"? I guess I gotta go look and see if there is a wire going to it.................

They just illustrate both AI and O2 sensor in this picture ...

What is shown with the little arrows

L

[StudMeyer]

Derp.

New member, as I was recently granted permission to join from a fellow owner Finally purchased a CRF after about 7,000 kms riding on rented machines in Thailand. Mine has 330 kms on it now. Going to get a new exhaust on tomorrow and new aluminum bar. Got other goodies coming over the next month or two.

Look forward to reading about all the mods coming out for the bike.

Here's a video I made in Thailand - footage from 2012. Stock CRF riding down doi suthep with a modified KLX

enjoy

[Krono]

Originally Posted by StudMeyer

Derp.

New member, as I was recently granted permission to join from a fellow owner Finally purchased a CRF after about 7,000 kms riding on rented machines in Thailand. Mine has 330 kms on it now. Going to get a new exhaust on tomorrow and new aluminum bar. Got other goodies coming over the next month or two.

Look forward to reading about all the mods coming out for the bike.

Here's a video I made in Thailand - footage from 2012. Stock CRF riding down doi suthep with a modified KLX

enjoy

Welcome and congrats for the video. I can feel the pleasure of driving

[gnath9]

Originally Posted by Jinksy

If I change the gear ratio from 14/40 to 13/43 will this give me better performance off the line?

13/42 and you won't have to mess with your chain.