The CRF250L Owners thread

I have the CR High on 2" Rox Risers ...... it's ok for 'attack position', but when casually riding in a standing position they're a little low. I'm 5' 9" but that's not the relevant measurement ... problem is, I can't remember the sleeve length on my dress shirts.

Yes, compared to this CRF spark arrestor, the "windows" that are covered with screen in the XR400R spark arrestor are HUGE by comparison. BUT, there is also a snuffer in the end of the XR400 spark arrestor that keeps the noise down to 86dB..I think. If you take that snuffer out, it is VERY noisy...way over he 96dB allowed in offroad events now by AMA. I created a snuffer with much less restriction similar to the ones created way back then by XR's only. By comparison, the CRF has fairly small windows...but no snuffer. My thought is to take a stock CRF spark arrestor, or a reasonable copy, and hog out bigger windows, add screen, and get to a reasonable sound level, with a reasonable power increase. I am personally not interested in spending $700 to remove 7 pounds, and end up with a nasty loud muffler...and yes....anything over 90dB is LOUD in my book...but the stock CRF is 80dB....is similarly over kill in the opposite direction. I have a sound meter, and plan on taking some dimensions off the stock XR400 "windows" and the CFR "windows" over the next couple weeks.

what about cables, did you have plenty of room ?

Rerouted the clutch cable ... don't remember exactly how. Rotated the throttle assembly on the handlebar to point the cables down instead of up.

80 dB, had no idea, seems pretty quiet, even by comparing to bikes I've had recently. I think some have said that this computer controlled system is way more sophisticated than ones in the past, mostly to keep the "backyard mechanic", out of the loop. Haven't heard from Ramz lately, I think he stated something like, you won't believe what information we can get out of this. Not quoting, but here on this thread, quite early on, he stated something similar. Others have noted that changing anything is a no no on current laws, nobody getting hung around here just lately, though, the pirates are taking mufflers off for the first mod. Oh crap, pirates, and KTM bashing, I though this was a CRF forum

New to the dual sport world. I'm trying to make my CRF faster off the line. How can I make this happen? Is "The Best Dual Sport" stage 1 kit worth the money? Please send me a private message and let me know.

Ramz appears to have abandoned us .... hasn't posted in this thread since mid-December. That's a shame ... all input is welcome.

It's been a while since we heard anything about this ... unless I missed it?

Looks like our missing owner has ordered and received the smaller of the two kits mentioned above. Maybe we can convince him to come back and provide some insight.

There was some previous discussion on it being a no-no to adjust the "sealed" throttle stop on the throttle body. I asked the stupid question of whether there is an adjuster on the throttle cable by the RH grip. Well, I looked at the bike show yes...there is one on the CRF. Here's an experiment for someone who has a CRF in a warm area that likes to stall when the throttle is allowed to slam shut and the bike rolls to a stop. Fiddle with the adjuster on the cable to the point where the idle is slightly elevated....go out and see if the bike still stalls. If it no longer stalls, then "idle speed setting" via the throttle stop is a fix of sorts. But I think thoroughly studying the service manual is essential. Mine's on order...when it arrives? Who knows!

Having had quads and dirtbikes all my life I've always joined the main forums for whatever particular vehicle I own. Is it weird to anyone that this thread is really the only place on the web(in English) that has good info and user input on the 250L?

just looked in the throttle operation section..to sum it up breifly..the adjustments at the bars are the minor adjustments and the adjustments down below are the major adjustments on the throttle cable.....something to consider and try, but just to cold for me right now...Thanks Ed

There's a dedicated forum for the CRF250L over at Thumpertalk.

http://www.thumpertalk.com/forum/351-crf250l/

I like the running commentary and social intercourse of a "global village" thread such as this one. However, it's easier to find information on specific topics when individual threads are created, and contained in one, convenient forum, such as the CRF250L Forum at Thumpertalk.

Spud

I'm not a back yard mechanic. I have 20 years of experence with this type of fuel injection and engine controller diagnosis, programing and custom tuning. I'm not bragging just informing you.

The injection system on the CRFL is designed using automotive technology. It is a closed loop speed density system.

I'm very experenced with this style system. I could put a turbo on it and dial it in correctly if there was room. I can basicly give you more info the a Honda tech can.

I'm willing to help as needed and answer any questions. You just have to put up with me. I can get kinda out there at times, just nicely point it out so I don't go on a rant. I've been hit in the head a few too many times and would like to get the knowledge/info out well I still can. I also have a brain tumor and other heath issues so please keep this in mind.

I haven't studied the system in detail yet since I don't own one... I plan on checking into it so I know what sensors it uses. Then I can explain how the system operates so everyone can understand.

I could use some help gathering pictures and verifying some sensor information so I can provide accurate information.

A chance to study the service manual(or get one) would be great. Then I could give step by step help and instructions as needed.

I believe it has the following sensors. If someone could double check the list and add the other possilble ones that would be great.


BMAP = Barometric/Manifold Absolute Pressure Sensor or a sensor for each.
TPS = throttle position sensor
CTS = Coolant Temperature Sensor
OS or O2 = Oxygen Sensor
IAC = Idle Air Control valve/stepper motor
CKP = Crankshaft Position Sensor
IAT sensor = Intake Air Temperature sensor

Some good detailed pictures would be great if someone could help me out. Lost has a good one and I plan on searching for more, I will give credit for each picture I can ID unless I can't find it or you don't want we to.

I think I want to start a new post like "CRF250L engine control details and tech"

If that sounds good to the CRF250L owner and followers out there let me know???

If you could PM me pictures, info or questions feel free. This way it won't clog up this thread and be great source of info that can be located easy.

Over and out...

Be careful when you do this because dirt could cause the throttle to stick further open since it won't have any slack.

I think a camshaft position sensor would be a first on a bike, A Japanese bike anyway...

That's great, Guru! Please do start a new thread, either here, or at Thumpertalk!

I believe the ECU is part #16 in the following diagram.



This unit only costs $73. Would it help your diagnosis if we chipped in and bought you an ECU?

Spud

Yes, you are exactly correct...this experiment is simply an experiment to see if the engine is going lean, or low on air & fuel and is momentarily "strangled" due to that lack of air. With your background...which probably included the trials and tribulations of emissionizing automotive carburetors, you are probably well aware of why they all had "dashpots" to allow the throttle to close the last little bit slowly and uniformly. The experiment will give us a clue of a cause for the stalls....but more than likely, this would not be the "proper" fix.

SPUD: You bring up another issue pointing out that the engine computer is only $73. I seem to recall reading a rumor that there were "race" versions of the computer that could be used on the CBR250R "street bike" that made much more than the 25 horse the CBR was rated at....does anyone else remember such rumors?

Putting a cam sensor on a single cylinder 4 stroke is unnecessary. It's extremely common to have a spark on BOTH upstrokes of the piston...one lights the mixture on the compression stroke, and the other just sparks on the exhaust stroke....the common description for this is "throw-away-spark".....so don't bother to look for a CMP on this engine

One thing I WOULD like to understand is how the second exhaust gas oxygen sensor is used on this engine....RamZ describes it in Honda literature....but I still don't understand the "whys".....and it better be a good explanation...oxygen sensors are not inexpensive....their value is in $$ not cents.

Using the abbreviations shown in the service manual:

MAP Sensor
TP Sensor
ECT Sensor
O2 Sensor
IACV
CKP Sensor

No Camshaft Sensor
Also has an IAT Sensor
Don't see a Barometric sensor