Stroker Kit for 230f? Make the 230 a 270?

[Pexeter]

My dad seems to think he's seen a stroker kit to achieve this. Do you know of one? Thanks..

[mcdrz]

The CRF230 already is a long stroke motor and has a greater stroke than a CRF450. Biggest kits out that I know of are all overbore up to 251 cc.

[coeshow]

As mcdrz mentioned, the CRF230 has a long stroke already. The ads your father read were more than likely refering to stroking and boring the CRF250R/X.

They (CRF250R/X) can be punched out to 300+ cc with a bigger piston, slightly longer stroke.

Even the longest possible stroker for a CRF250 would still be much shorter than the stock stroke of the CRF230 at 66.2mm !

[Toast]

Coeshow,

I know there isn't a a stroker kit for it but is there room for one? I'd think the 230 has to be swinging pretty close to the case. Just thought you might know.

Thanks!

?

[coeshow]

amazingly there is a little room for stroking, but not much. The rod comes closest to strikingtrans mission parts first. You might be able to gain 4-5mm additional stroke.

But even if you increased the stroke to 70mm, the displacement would only increase to 235cc with the stock piston, and if you added a 70mm piston to build up "square" again (70mm x 70mm) it would only displace 269cc, so that is about all that is possible.

The CRF250R/X's can get to that displacement with a Big-bore kit only.

On the CRF230 it would be a lot of work, but do able. I feel that this would "Max-out" the engine for any realistic increase.

I had visions of 300cc a long time ago, but it ain't gonna happen.............

[See-Are-Ef-Too-Thir-T-Ef]

So, would adding a stroker if you could, give it more bottom end?

[i heart ridin]

yes, bore= hp, stroke =torque. but do you really need more low end on the 230? thats what its all about. i would think that a big bore kit would be much more desirable to give you more hp than to give you more torque.

[Toast]

Do both & gear it up. ?

[Jimarea51]

My grandson has a 2008 crf230f. He bought it with a bad cam. I was wondering if I big bore Piston and cam. How would it work and if anyone can give me some advice on the best way I can get more power out of it so he doesn't want to sell it. The bike is mint.

[bajatrailrider]

i have 230fs  big bore and stroked . One that only has pwk carb 28mm day and night power difference.  Do that  get stock cam and rockers you could do the 233 big bore too. For me if get racing cam it can be hard on valve train . Unless you know how to deal with it. The biggest hold up on power 230 is stock carb.

[adnohguy]

2 hours ago, bajatrailrider said:

i have 230fs  big bore and stroked . One that only has pwk carb 28mm day and night power difference.  Do that  get stock cam and rockers you could do the 233 big bore too. For me if get racing cam it can be hard on valve train . Unless you know how to deal with it. The biggest hold up on power 230 is stock carb.

And for the engine power output, header pipe diameter, ignition CDI box, porting, fly wheel key, lack of compression, stock camshaft, do not deny it 

For handling: Which cannot be denied either, front and rear suspension upgrades and both tires replaced with ones that actually work well, 

Edited March 22, 2023 by adnohguy

[bajatrailrider]

Yes Master are you trying to scare all for building a 230?   My 230 I could open bike shop with all parts I removed . Honestly my stock engine 230  pwk carb only is a ball to ride. 

[adnohguy]

53 minutes ago, bajatrailrider said:

Yes Master are you trying to scare all for building a 230?   My 230 I could open bike shop with all parts I removed . Honestly my stock engine 230  pwk carb only is a ball to ride. 

Don’t be scared, it’s a piece of cake, only minimum requirements, don’t even need a 10cc, “big bore”,  waist of cash ? 

Edited March 22, 2023 by adnohguy

[chadzu]

On 3/20/2023 at 10:27 PM, Jimarea51 said:

My grandson has a 2008 crf230f. He bought it with a bad cam. I was wondering if I big bore Piston and cam. How would it work and if anyone can give me some advice on the best way I can get more power out of it so he doesn't want to sell it. The bike is mint.

These little engines do respond well to the normal hop up stuff.  A kit like the Athena 67mm one is well made and easy for anyone to install.  You get a few more cc's and some compression.  Exhaust can make a noticeable difference.  Do standard "power up" stuff to carb and airbox.

There is a whole different rabbit hole you can go down with these engines to make power.  The down side is that for what it costs to have one of adnohguys engines built you could buy a nice modern 250f which is what your grandson wants anyway. 

[adnohguy]

8 hours ago, chadzu said:

These little engines do respond well to the normal hop up stuff.  A kit like the Athena 67mm one is well made and easy for anyone to install.  You get a few more cc's and some compression.  Exhaust can make a noticeable difference.  Do standard "power up" stuff to carb and airbox.

There is a whole different rabbit hole you can go down with these engines to make power.  The down side is that for what it costs to have one of adnohguys engines built you could buy a nice modern 250f which is what your grandson wants anyway. 

67.5 bore X 72mm stroke= 251cc’s

[Oldie230]

A 270cc build is quite a large and expensive project that requires a new larger sleeve cylinder and cases bored to accept it. It also requires disassembly of the cases to install the stroked crank. And to get the best from it requires good headwork, a good cam, better carby,  bigger exhaust and probably a performance CDI

If you do the Athena kit (slightly more cc's and compression), cam, head porting, PWK carby, exhaust, CDI, you could probably get quite a boost without the extra cost and effort of the bigger bore and stroking. 

And then you need to start on the suspension.....

[adnohguy]

12 minutes ago, Oldie230 said:

A 270cc build is quite a large and expensive project that requires a new larger sleeve cylinder and cases bored to accept it. It also requires disassembly of the cases to install the stroked crank. And to get the best from it requires good headwork, a good cam, better carby,  bigger exhaust and probably a performance CDI

If you do the Athena kit (slightly more cc's and compression), cam, head porting, PWK carby, exhaust, CDI, you could probably get quite a boost without the extra cost and effort of the bigger bore and stroking. 

And then you need to start on the suspension.....

Yes absolutely with proper porting and your stated extras but you will need to upgrade the clutch to handle 25 RWHP no matter how you go but you should do the suspension and tire upgrade FIRST

And for best results use race fuel for 12.5-1 compression. 

[Jimarea51]

I’m interested in this 230 kit I have a 2008 crf230f.

[adnohguy]

11 hours ago, Jimarea51 said:

I’m interested in this 230 kit I have a 2008 crf230f.

How thick is your wallet?
Send crank to crank works and have it stroked 6 mm +.040 have a custom rod built so the squish comes out to .000. Custom order 4 new 69.mm pistons, ( minimum order) a sleeve, bore the cases and cylinder to fit the sleeve. Then bore the cylinder (with the new sleeve in it already) then have a custom solid copper head gasket built and then assemble. There your go, your 269cc 230f is ready to ride. But wait there is more: you need a performance cam, pro com, bigger carb, (depending on the carb you choose it will need to be re jetted properly, custom porting and a larger header pipe. The if you do not upgrade your suspension and tires then you will constantly crash and that hurts a lot usually. 
Again, how thick is your wallet? 

Edited January 18 by adnohguy