Jump to content
Sign in to follow this  

DIY "woods" port mods for cr250 ( pics)

Recommended Posts

Ok guys i have had a few of you ask me what the hell i was talking about with my woods mod to my cylinder, i take no credit for this eric gorr shows a picture of this in his book and i just figured out the rest on my own

heres what you need

a dremel tool AND A CHAIN SAW BLADE STONE YES ! THATS NOT A TYPO and some 400, 800 and 1200 sand paper

use slow speed and work the radiuses there are 2 rules

1) go SLOW with the speed and don't stop moving

2) DO NOT PUSH use a light steady touch

if you compare your cylinder to my photo's you can see what i did to open up the sub intake (boyssen ports)

the next step in to get a sand bit and use the grits i outlined in progression

the best way to smooth them out is to wrap a small piece of sand paper around the mandrel ( bit) and tape the bottom letting the top spin like a helicopter this will nock down all high spots, this is how the big boys do it

last AND MOST IMPORTANT STEP !

spray with carb cleaner compressed air fallowed by simple green, then dunk in soapy water NOW DO THIS AGAIN 4 TIMES !!!

idiot3.jpg

idiot2.jpg

idiot1.jpg

Share this post


Link to post
Share on other sites

so basically you just opened up the intake ports slightly? did this help improve bottom end then as well?

Share this post


Link to post
Share on other sites

Wish someone would post how to stuff cases on 02+ for more bottom end

Share this post


Link to post
Share on other sites
Wish someone would post how to stuff cases on 02+ for more bottom end

That is supposed to be the magic fix for late model CR125s, so I'm interested. 'Course, I still don't even know what "stuff cases" means....

JayC

Share this post


Link to post
Share on other sites
That is supposed to be the magic fix for late model CR125s, so I'm interested. 'Course, I still don't even know what "stuff cases" means....

JayC

the late models have too much case volume, that's one of the reasons they dont have much bottom end, I've read magazine articles about case stuffing, and people have said they have had it done, but nobody has posted a howto, supposedly it's not hard at all, I've seen how to it to a KTM

but not for honda's yet, gotta know the right spots to hit

Share this post


Link to post
Share on other sites
the late models have too much case volume, that's one of the reasons they dont have much bottom end, I've read magazine articles about case stuffing, and people have said they have had it done, but nobody has posted a howto, supposedly it's not hard at all, I've seen how to it to a KTM

but not for honda's yet, gotta know the right spots to hit

Here are some pictures of mine. Hope it helps.

cr250cases1.jpg

cr250cases2.jpg

cr250cases3.jpg

cr250cases4.jpg

cr250cases5.jpg

cr250cases6.jpg

cr250clyportedtransfer.jpg

cr250cylported.jpg

cr250trans.jpg

Share this post


Link to post
Share on other sites

yes i opened up the intake ports and blended them into the transfers,

there are alot more modifications that can be done to these cylinders but this one is basic enough for the average joe to do with out screwing up

another word of advise would be to lay the base gasket on the cylinder when you are cutting the metal, that way if you slip you'll mark up the gasket and not your sealing surface

the reason we are using the chainsaw blade stone is it is not nearly as aggressive as a carbide bur and is easier to control

Share this post


Link to post
Share on other sites
Here are some pictures of mine. Hope it helps.

thanks, i figured there would be a lot more material added than just those spots

more like this

EpoxyWM.jpg

Share this post


Link to post
Share on other sites
yes i opened up the intake ports and blended them into the transfers,

there are alot more modifications that can be done to these cylinders but this one is basic enough for the average joe to do with out screwing up

another word of advise would be to lay the base gasket on the cylinder when you are cutting the metal, that way if you slip you'll mark up the gasket and not your sealing surface

the reason we are using the chainsaw blade stone is it is not nearly as aggressive as a carbide bur and is easier to control

did you notice a drastic change in power by doing this mod?

Share this post


Link to post
Share on other sites

there was no overall gain HP wise, however it like to chug more and it took all hesitation out of the bottom end, i did notice less wheel spin after i did this as well

the only way i can explain it ( with out you hearing, seeing riding ect) would be it feels cleaner in the tight woods, i ride bar tight single track and race in the J-Day series up here in new england so i helped me for what i do

im not a pro but this will help if you ride woods

Share this post


Link to post
Share on other sites

ohok thank you, it seems like a good idea but im not sure id benefit from this much becasue i ride mx, and am mostly a top end person

Share this post


Link to post
Share on other sites

Nice job, I have Eric gorr transfer port mods, Iv really been wanting to match the head and cases with epoxy.. Looks great!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×