CRF250 L thread

[garyboy]

the o/2 sensor reads air fuel ratios and relays the info to the ecu at idle and low revs the ecu can adjust the a/f ratio at low settings of the throttle this closed loop monetering ..the 02 sensor on the honda are whats called narrow band so only deal with lower revs and tickover ..the is absalutly no advantage to disconnecting it as it does nothing to the higher fueling demand in the rev range and is there to adjust the a/f ratio at low revs and idle

this is the common misconception by people who never ridden off-road, because when doing technical off-road we are quite often at the low revs.

Besides o2 sensor doesn't read air/fuel ratios, it just simply generates few volts when there is difference in oxygen level between outside air and gases in exhaust. That's it.

I don't know nuffink about this technical stuff and had never heard of a lamda sensor before (a lamb sensor, yes) but I do know that the levels of oxygen in any exhaust is drastically lower than in the outside air .. because it is precisely that element of the air that is used up in the combustion process.

[Arthur Pint Motor]

2017 model has some tweaks to the engine - bigger throttle body and front pipe, new EFI map. The rally model has a bit more travel, maybe they took the opportunity to fit better quality suspension?
Shame they don't offer a CRF250L and a CRF250LX with improved suspension for a couple of hundred quid more. I'm sure £20 worth of suspension bits, at factory prices, would do the trick.

[AndyB]

Most manufacturers miss a trick when they don't offer a factory supplied suspension upgrade because it's usually one of the first changes serious riders make to a bike. The other obvious candidate for a factory supplied suspension upgrade would have been the Tenere but apparently I'm wrong when I say they need it :pinch:

[minkyhead]

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[catcitrus]

the o/2 sensor reads air fuel ratios and relays the info to the ecu at idle and low revs the ecu can adjust the a/f ratio at low settings of the throttle this closed loop monetering ..the 02 sensor on the honda are whats called narrow band so only deal with lower revs and tickover ..the is absalutly no advantage to disconnecting it as it does nothing to the higher fueling demand in the rev range and is there to adjust the a/f ratio at low revs and idle

this is the common misconception by people who never ridden off-road, because when doing technical off-road we are quite often at the low revs.

Besides o2 sensor doesn't read air/fuel ratios, it just simply generates few volts when there is difference in oxygen level between outside air and gases in exhaust. That's it.

Sorry--you are wrong--again!--and Minky is correct--I would give up. Lambda refers to the symbol given to the actual air/fuel ratio versus stoichiometric. The primary reason (general) for them is to remove excess oxygen for 3 way catalysts so that NOx can be removed(by monitoring oxygen levels in the exhaust and giving a signal for an appropriate fuelling change--a lambda of unity, or an actual stoichiometric air/fuel ratio of roughly 14.65:1 will produce NO SPARE OXYGEN in the exhaust)--but in this case (and its the same for my WR250R where I've also left the sensor in) its function is actually to control idle more accurately and also UPFUEL the engine so that at warm up and low revs the catalyst has "fuel" to light off asap and work (in removing hydrocarbons). It does seem an incongruity but my Yamaha was also fitted with a SAS(secondary air system) which adds air into the exhaust to mix with the unburnt fuel(again at low revs and warm up) to form a combustible mixture with the fuel passing through for catalyst light off--the lambda sensor effectively compensates for this added excess air. I've left mine in but with all other stuff removed--and a non cat GYTR muffler--and it runs fine--probably because its still getting idle mixture control.

[robson]

Most manufacturers miss a trick when they don't offer a factory supplied suspension upgrade because it's usually one of the first changes serious riders make to a bike.

and they're probably right because for 90% riders out there stock suspension is usually adequate. Simple economics. When you're riding in relaxing mode crf250l stock suspension is good enough even for heavier riders like myself. When you start to push it then we have a problem but how many actually do...It's funny, people are spending lots of money on fancy suspension to ride 30 mph like on some recent clips in this thread.

[robson]

Sorry--you are wrong--again!--and Minky is correct

you wish but you're both wrong, again! but I don't care anymore.
Write more BS like that on this forum. Next time read with understanding.

[Arthur Pint Motor]

Most manufacturers miss a trick when they don't offer a factory supplied suspension upgrade because it's usually one of the first changes serious riders make to a bike.

and they're probably right because for 90% riders out there stock suspension is usually adequate. Simple economics. When you're riding in relaxing mode crf250l stock suspension is good enough even for heavier riders like myself. When you start to push it then we have a problem but how many actually do...It's funny, people are spending lots of money on fancy suspension to ride 30 mph like on some recent clips in this thread.

Most BMWs are sold with the M-Sport package and a high proportion of buyers also go for the sports suspension. 90% of drivers would be better off (never mind adequate) with standard suspension. I think you underestimate how much punters will pay for factory fitted "upgrades" and Honda are missing a trick on making more profit.

BTW the KLX is supposed to have marginally better suspension than the CRF. It's not hard to get the rear end on mine well out of shape below 30MPH and I only weigh 10.5 stone!

[halfpint]

you dont get out of shape below 30 mph. It is just off roading ride trough it and carry on. most the problems come with the right hand twisting ! just ride the bike and stop wasting your money . if you want to go fast with control buy a better bike .Its a trail bike simple

[catcitrus]

Sorry--you are wrong--again!--and Minky is correct

you wish but you're both wrong, again! but I don't care anymore.
Write more BS like that on this forum. Next time read with understanding.

OOOPS!!--struck a nerve there I guess!!--I won't bore you with my qualifications that give me a bit of understanding --simply suggest that you do some reading on the subject. This is obviously the right room for an argument so I will simply leave it there--thats what comes of trying to shed a little light--the truth will out as always. Back on the subject the CRF 250L is a good budget bike as it comes--and if people want to play and improve then its up to them--its part of the fun and improves the bond.