Upgrades for CRF250

[AllanB]

Back in Thailand soon, but before I leave Europe would like to prepare to upgrade my 2017 CRF250, possibly bring some gear with me from the UK.

 

I am looking to improve the torque band and know there is a lot of kit out there for doing this, so looking a little advice.

 

We ride 2up + luggage and like to ride mountain roads, so anything that would help that cause.

[Kwasaki]

1 hour ago, AllanB said:

We ride 2up + luggage and like to ride mountain roads, so anything that would help that cause.

I'd say get bigger bike unless your in no hurry.

Is your bike pre upgrade 2017/2018 model.

I'm happy enough with mine as it is with Honda's latest upgrades.

I read do away with the 'catalytic' change ECU for a CBR250 unit but then fueling needs to be remapped.

Spending dosh on expensive upgraded exhausts etc and other kit, much easier to buy bigger cc bike IMO. 

[AllanB]

3 hours ago, Kwasaki said:

I'd say get bigger bike unless your in no hurry.

Is your bike pre upgrade 2017/2018 model.

I'm happy enough with mine as it is with Honda's latest upgrades.

I read do away with the 'catalytic' change ECU for a CBR250 unit but then fueling needs to be remapped.

Spending dosh on expensive upgraded exhausts etc and other kit, much easier to buy bigger cc bike IMO. 

Need a fairy light bike to load onto my truck, not looking for a big incease just a wider torque band if possible. How is the remapping done?

[thaiguzzi]

7 hours ago, AllanB said:

to upgrade my 2017 CRF250,

Trade it in for a Bill Blue KLX 350...

[canthai55]

http://electronicjetkit.com/DirtBike/default.asp

[canthai55]

2 hours ago, AllanB said:

 How is the remapping done?

http://electronicjetkit.com/DirtBike/default.asp

Used by guys who increase breathing on stock engines.

Little use otherwise

[Kwasaki]

15 hours ago, AllanB said:

Need a fairy light bike to load onto my truck, not looking for a big increase just a wider torque band if possible. How is the remapping done?

Get a Honda's CB500X adventure.

Personally messing about with torque on a little 250 is not worth the effort.

Remapping is done on a computer connected to the bikes ECU.

 

 

[AllanB]

17 hours ago, thaiguzzi said:

Trade it in for a Bill Blue KLX 350...

Nice but not available.

 

CB500 an extra 30kg.......

 

Is EJK available in Thailand, or is it a USA import?

[OneMoreFarang]

I understand when people look in Thai forums for Thailand specific information.

But I think if you want to get the best information about a specific bike look at a forum just for that bike.

I just googled it and I found this one with tons of information:

https://www.hondacrf.com/forums/forum.php

And I am sure there are others with lot of experts for your bike.

[drift]

 

 

https://thumpertalk.com/forums/forum/351-crf250lmrally/

 

 

[canthai55]

5 hours ago, AllanB said:

CB500 an extra 30kg.......

And twice the HP ...

This conversation has Deja Vu written all over it.

From the topics re: buying a Lifan, to the topic of buying a CRF

Those in the know recommended a 500X years ago for what you want a bike to do

I put my Dyna into the back of a 4 door pickup - so weight and size is not an issue

[thaiguzzi]

6 hours ago, AllanB said:

Nice but not available.

 

CB500 an extra 30kg.......

 

Is EJK available in Thailand, or is it a USA import?

It is.

You buy a S/H or new KLX 250 here.

Then you send big bucks to the States for your BB big bore kit. Then you assemble it all with either a PC5 or a huge Mikuni kit.

 Bingo, 40 bhp, torque across the board and 10 kgs LESS than your CRF.

[Farangwithaplan]

11 hours ago, Kwasaki said:

 

 

As said by a few others, the best bet is a CB500X and see if you can find some lighter rims, get an after market suspension front and rear and go from there.

 

I have a CBX and I still find it underpowered at highway speeds with someone else on the back. There isn't a great deal of drive riding solo but it is acceptable. Two up with a bit of luggage is a case of needing to drop down a few gears at least to safely overtake. I would shudder at having to do it on a 250cc bike two up.

 

But to answer your question, a new input and output cam and then a piggyback board on to the ECU to modify fueling for the new cams will have the greatest effect on output. But whether the cost would justify the return is debatable.

 

If you have money to spend, then get a freer flowing exhaust and ditch the pair valve / catalytic converter (if your model has it).

 

Id really prefer to put the money in suspension and HH pads and braided line for the front brake of a CBX. It is a reliable fairly nimble and capable machine for your needs by the sound of it.

 

[taninthai]

No matter what you do to this bike it is still not gonna be ideal or have the low down power for what you want it for which is 2 up riding with luggage????,,,,,,,,,,,,,,,cb500 seems best advice or just be content with what you have.

from reading some replies.........stop putting your bike in the truck and buy a proper touring bike cb500/versys 650 and tour on it.........it seems that’s what you want to do but are just going the long and awkward way about it.

done some quite big trips on my crf and it’s ok 1 up,done 70 Kms once with the x misses on the back and it was horrible,I honestly don’t know how you ride and enjoy it 2 up with luggage.

 

[Rhys]

...I'd have to agree with the rider suggesting move up to the CB 500X.... Better for your needs here...and it is ready..  plus the wait to get the bike.. 1  month..in some places...

[kelboy]

Last year me on my cb500x  and kawasaki 650 versys went down to the Malaysian border with no power problems between us .next month we are going to Esaan me on cb500x and kawasaki on his crf 250 and still no power problems between us. Normally we ride about 120km if you go much faster than that your asking for trouble. And yes some times we do go faster. So what  ever bike you have just enjoy it.we both have a rack on the  back for a small bag and that's all we need. 

[AllanB]

3 hours ago, kelboy said:

Last year me on my cb500x  and kawasaki 650 versys went down to the Malaysian border with no power problems between us .next month we are going to Esaan me on cb500x and kawasaki on his crf 250 and still no power problems between us. Normally we ride about 120km if you go much faster than that your asking for trouble. And yes some times we do go faster. So what  ever bike you have just enjoy it.we both have a rack on the  back for a small bag and that's all we need. 

If I enjoyed highway riding at all in Thailand I would have bought a CB500X, it's a great bike. I have a 400cc Shadow for that and it has plenty of power, ample torque two up. It would probably even fit on the back of the pickup, but is very cumbersome.

 

The CRF is not that far away for being FFP, so I will look at a few other forums, try to improve things. We did the MHSL earlier this year and it was just a bit lacking, we weren't carrying much. My (heavy) mate and his Mrs were on a Forza and that was okay and he was carrying the kitchen sink.

 

Will try to learn about this remapping malarcky.

[Gnasher328]

The best thing I did was have the original exhaust 'gutted'. It was 1000Bht, sounded good, not too loud, doesn't get a second look from plod or border guards abut it made an unbelievable difference to the low end torque. The gap between 1st and 2nd is no longer a problem off road and whereas previous rides up the 118 to Chiang Rai had seen the need to drop down as low as 3rd gear now I can do them in 5th &6th .The top end is as good as a previous 'sports' exhaust which killed the low end torque and sounded vile and embarrassing.

Then did the CBR 300 upgrade which made the same difference again but was obviously a lot more expensive. Well worth it all, now for solo touring I really don't need a bigger bike, now had the CRF over five years;-)

[AllanB]

4 hours ago, Gnasher328 said:

The best thing I did was have the original exhaust 'gutted'. It was 1000Bht, sounded good, not too loud, doesn't get a second look from plod or border guards abut it made an unbelievable difference to the low end torque. The gap between 1st and 2nd is no longer a problem off road and whereas previous rides up the 118 to Chiang Rai had seen the need to drop down as low as 3rd gear now I can do them in 5th &6th .The top end is as good as a previous 'sports' exhaust which killed the low end torque and sounded vile and embarrassing.

Then did the CBR 300 upgrade which made the same difference again but was obviously a lot more expensive. Well worth it all, now for solo touring I really don't need a bigger bike, now had the CRF over five years;-)

Sounds like the answer for me, do you have any other details, what was the 1000 baht for, did a company do this for you?

 

A better engine note wouldn't be a bad thing either, the CRF is bit dull, the Lifan sounded a lot better and got better with age.

[kelboy]

6 hours ago, AllanB said:

Sounds like the answer for me, do you have any other details, what was the 1000 baht for, did a company do this for you?

 

A better engine note wouldn't be a bad thing either, the CRF is bit dull, the Lifan sounded a lot better and got better with age.

Had the cbr250r a and changed exhaust air filter and chip the engine, made a big difference, all for under 400 pounds on ebay.Good luck. 

[Farangwithaplan]

15 hours ago, Gnasher328 said:

 The gap between 1st and 2nd is no longer a problem off road and whereas previous rides up the 118 to Chiang Rai had seen the need to drop down as low as 3rd gear now I can do them in 5th &6th .

That is a massive change and being able to have the same drive in 6th gear as you previously had in 3rd gear just due to a freer flowing exhaust sounds suspicious to me unless your exhaust had previously been somehow abnormally blocked by foreign and non stock items.

 

[Kwasaki]

On 10/8/2018 at 10:05 PM, Farangwithaplan said:

But to answer your question, a new input and output cam and then a piggyback board on to the ECU to modify fueling for the new cams will have the greatest effect on output. But whether the cost would justify the return is debatable.

Exactly it would be a waste of time two up and luggage on a 250.

As for including full set of after market pipes best put money altogether of above and buy bike with a bigger engine.

[Kwasaki]

2 hours ago, Farangwithaplan said:

That is a massive change and being able to have the same drive in 6th gear as you previously had in 3rd gear just due to a freer flowing exhaust sounds suspicious to me unless your exhaust had previously been somehow abnormally blocked by foreign and non stock items.

 

Yeah I would be surprised with no catalyst and a whooping 37 cc gain it would do that. ???? 

[AllanB]

I like the idea of gutting the stock exhaust, I am sure it is government restricted and if I cock it up I can easy get an aftermarket box, or even get a stock box traded in. I am also told that the airflow in can be increased merely by removing the snorkel, so another reversible decision. Then a 13t sprocket, also non damaging, which I will start with.

 

Then there are the costs, these mods are cheap and if they work will make me a happy bunny.

 

So now I am left with remapping and since the ECU is monitoring air flow isn't there an automatic adjustment element here?

 

I really don't want to changing bikes again, especially in Thailand which is not the easiest place to buy and sell. Out of the frying pan, etc. I have two homes to run so my cash is spread quite thin and I am by nature a cheap Charlie. 

 

[Farangwithaplan]

1 hour ago, AllanB said:

I like the idea of gutting the stock exhaust, I am sure it is government restricted and if I cock it up I can easy get an aftermarket box, or even get a stock box traded in. I am also told that the airflow in can be increased merely by removing the snorkel, so another reversible decision. Then a 13t sprocket, also non damaging, which I will start with.

 

 

I don't want to sound like a downer but removing the snorkel of the air box infeed rarely if ever improves performance on a bike built in the last 25 years. The reason why is because of fluid or air dynamics. A bigger hole does not necessarily mean more air to the inlet valves or better mixture of air and fuel.

 

Those little snorkels are engineered in wind tunnels or wind chambers to maximise the pressure and swirl and probably 20 other things, to give the optimal flow (with cost and location and size of airbox restraints).

 

People get the emotion of more power from hearing the louder intake noise I guess. I used to and probably still do, but many hours on many different bikes have taught me I was tricked by my own senses.

 

If the bike has the torque, gearing changes can help. The other thing to do on low capacity bikes is to lower the reciprocating mass. IE: make anything that spins lighter and it will make a difference. Try for lighter gauge chain. I don't know what the CRF runs but if it is a 420 chain, change out to a 410 as long as the tensile strength is okay. That will mean a lighter chain, thinner and therefore lighter sprockets, too.

 

Then go to anodized aluminium sprockets. They won't last as long as steelies but with the change in gearing and the lighter components, there will be change. Finally, find a lighter wheels.

 

The cost of cams, oversized piston kit, fueling module is a fair bit of coin for not a lot of return. But then again, so are wheels generally. But if it is a hobby, do the lot and enjoy it.

[AllanB]

4 hours ago, Farangwithaplan said:

I don't want to sound like a downer but removing the snorkel of the air box infeed rarely if ever improves performance on a bike built in the last 25 years. The reason why is because of fluid or air dynamics. A bigger hole does not necessarily mean more air to the inlet valves or better mixture of air and fuel.

 

Those little snorkels are engineered in wind tunnels or wind chambers to maximise the pressure and swirl and probably 20 other things, to give the optimal flow (with cost and location and size of airbox restraints).

 

People get the emotion of more power from hearing the louder intake noise I guess. I used to and probably still do, but many hours on many different bikes have taught me I was tricked by my own senses.

 

If the bike has the torque, gearing changes can help. The other thing to do on low capacity bikes is to lower the reciprocating mass. IE: make anything that spins lighter and it will make a difference. Try for lighter gauge chain. I don't know what the CRF runs but if it is a 420 chain, change out to a 410 as long as the tensile strength is okay. That will mean a lighter chain, thinner and therefore lighter sprockets, too.

 

Then go to anodized aluminium sprockets. They won't last as long as steelies but with the change in gearing and the lighter components, there will be change. Finally, find a lighter wheels.

 

The cost of cams, oversized piston kit, fueling module is a fair bit of coin for not a lot of return. But then again, so are wheels generally. But if it is a hobby, do the lot and enjoy it.

I am working on the assumption that if I "gut" the exhaust I have already screwed up Honda's good work and am trying to even things up in terms of input versus output AFRs. Removing the snorkel has a potential airflow increase of around 25%, given that the filter element is not restrictive. Plus Honda are also under instruction from legeslators when they design their engines. Good old Al Gore. 

 

I think your point of lightening the drive train will do little to improve torque, but have heard that the new 13t gearing works. This is a brand new bike and it is not in my remit to start stripping it down to modify.

[Gnasher328]

Hi Again

The original info is on Ride Asia, specifically :-

https://www.rideasia.net/motorcycle-forum/threads/crf-mods-and-improvements.2338/page-3

 

Note the comment by 'TwoWheels' below my post. My comments on the gears said 'as low as 3rd now 5th 6th' that is I can use 5th instead of third. Now no need to change sprockets.

Didn't remap, just fitted the CBR 300 throttle and corresponding ECU, plug chops firn and been OK for 000's of Ks.

Somewhere in that thread about the other work - including repairing the indicator and making a shield for it!

Removed the snorkel but kept the original filter - gets clogged real fast in dusty conditions.

Have fun, Tim

[Kwasaki]

Oh dear you really don't get it but I would say you really do not want to.

[AllanB]

5 minutes ago, Kwasaki said:

Oh dear you really don't get it but I would say you really do not want to.

You say "Exactly it would be a waste of time two up and luggage on a 250." Don't quite undestand that, I rode VN on a 100cc well used Wave and plenty of guys out there are riding the range on a 125, why is 250cc not enough.

 

My issue is with nothing more than the poor torque band, I am not looking to win the Dakar.

[Farangwithaplan]

11 hours ago, AllanB said:

Removing the snorkel has a potential airflow increase of around 25%, given that the filter element is not restrictive. Plus Honda are also under instruction from legeslators when they design their engines. Good old Al Gore. 

 

I think your point of lightening the drive train will do little to improve torque, but have heard that the new 13t gearing works. This is a brand new bike and it is not in my remit to start stripping it down to modify.

As I said, total airflow is not always the most important thing in regard to an airbox. Reread my post. All engine manufacturers balance a fine line between power and legislation for noise and emissions. Why keep the airbox at all if removing air restriction is the only factor? You could just have an open air filter with a shroud over it to protect it from weather?

 

If you don't agree with lighting the mass of moving parts then you are disagreeing with physics - not me. But yes a smaller sprocket will lower change the gearing and is a common option. But power output will not change and you still have the heavier parts to turn to get movement.

 

a 13 tooth front is getting a very tight radius and might be fine for the CRF, but I would go to a larger sprocket at the rear. Chain will last longer and so will the polyurethane chain guide on the from top of the swing arm near the front sprocket. Ratios are easy to work out. What is front and back standard teeth?