CRF 2009 af 1989 cr250 Build part 1
I have had a look through the site and there are plenty of impressive builds on here. Thought id share where im up to with my 2009 af cr 250 build.
so its another af build with cr 250 1989 motor.
let me know what you think
I Bought the crf 250 complete bike for $1500 off gumtree (auz version of craigslist)
Was pretty rough when i got it, front forks were rock hard n not very well looked after. Got a new set of plastics and graphics, suspension re sprung n valved, top end done, n heap of little things done to it.
Got a new yoshi pipe for it,
rode it twice then this happened think the new top end made the bottom end let go..
Had a go at rebuilding it all myself (I am a builder not a mechanic)
So finally got it all back together and running. yesss
only got another 10 or so rides out of it and something let go in the motor so i couldnt bring myself to spend another $1000 on another rebuild kit. I pulled the motor and parted what i could. Was so over four strokes, and realised for the money i had spent on this bike by this point i could have bought a pretty decent ktm to start with. But i couldn't bring myself to sell it as a roller and lose on everything that i had done to the bike already. The suspension cost me a bit over a grand alone so i figured i would keep it and make the most of a bad situation.
Last edited by nrb188; 09-08-2016 at 12:34 AM. Reason: photos were not working..
Started looking for a cr 250 motor. It took me a month to find one, found it at a bike shop in newcastle. Some one had brought it in for an rebuild and never payed or picked up. purchased it for the price of the rebuild and got it posted up to the gold coast. Came with a pretty ugly pipe and bare motor but price was right and its slim picking for motors here in Aus so i felt pretty lucky to have found it.
Thankfully the 89 swing arm bolt is the same size as the 09 crf 250 motor.
Just had to bolt it in and align sprockets.
This worked by using standard 2009 crf right hand side bushing and cr125 bushing from an 02? pretty sure it was. lined up nicely. part was only $25
While i was was waiting for the motor to arrive. I decided to make a table for the build as i figured it would be a while before i finish the build and my back is shot so bending over all the time wasn't going to be an option.
perfect hight, put wheels on it so i can move it around.
So with the table built, made easy cutting of the bike. Y piece out
I wanted to keep this build as stock looking as possible for handling and for appearance, so going to try and re use stock Y piece.
Notching out THE Y piece to reuse.
Cutting mounts off
With deciding to re use the y piece i only needed to get lower fram rails. I will be making the rest of the mounts etc
With the Y piece out i could rough fit the motor and see how things are looking for clearance's.
Stock crf head stay mounts are correct angle for the cr motor, love the little wins on a project. (il be remaking them, but its nice that i could slap a bolt through and hold the motor roughly where i needed it)
looks like bottom rails have to go for the 89 cr 250 motor to work. (Do not want to notch it)
If you do this slowly, you will be able to pry out the old tubing.
With the bottom rails out i can fit the motor as it needs to be positioned for air boot/exhaust.
Last edited by nrb188; 09-08-2016 at 12:55 AM. Reason: Forgot to use capital letters.
I really wasn't sure what was the best carb to use for this build for length of carb/ease of air boot fitment etc. So i just got the best one to run with the cr and hopefully making the rest work around it. The air boot is off a 98? i think its ended up being 20mm short for length and super tight against the shock. It wont work but i had nothing to go off and the boot only cost me 30$ so any other suggestions on whats the best boot to us that would be great guys
this pic probably shows fitment best.
With the boot not lined up how i need it, i cant rotate the motor to where i know it will finish sitting. This means i couldn't confirm where best to finish the y piece on the frame and cut lower frame rails in place.
Rough pipe fitment
checking airboot/carby sizes match up
Where its at the moment.
Y piece sitting in roughly new spot, notch it out slowly and taper it to suit the frame and it will fit snug as.
So thats pretty much where i am up to with it, hope the photos help anyone out doing the same build or wants to. Any feed back is good.
Last edited by nrb188; 09-08-2016 at 01:11 AM. Reason: photos were not working..
Looks like the start of a fun project, and the opening of a can of worms. I think I can say without reservation, the gen 4 CRF250/CR250 combination is the biggest PITB to pull off. Fortunately, it's also produces the best ever of all worlds if you
are a two stroker.
I know there is always more than one way to get the results you want, but having built a couple of these using a similar combination, I can offer some of what I learned from doing it my way and also some problems you might face that you may
not be aware of.
First of all, unless an 89 CR250 engine is significantly different dimensionally from a 2000/01 CR250 engine, you will have to remove a lot more than the lower frame rails for a CR250 engine to sit anywhere close to the correct angle. If you check
out my post from a similar build, I went into some detail on what I had to do.
Next, after you remove all the material from the rail pockets, you will not be able to use straight bottom rails without notching them. In addition to fouling the Right side case cover, flat rails will not allow enough room for a lower engine mount.
If you try to use straight rails and just angle them down for clearance, you will end up with a new radius as the rails bend up to meet the "Y" and the loss of a few inches of ground clearance. Probably not the best solution.
To sum this part up, repositioning the "Y" is the least of your worries.
Next is the airbox/boot. You're on the right track by mocking the engine and box up, but it's not going to fit without looking like some kind of a rube goldberg contraption. First thing you will have to do is get the engine where it is parallel to the
ground and the CS to swingarm pivot bolt is the same distance and angle as they were on the CRF engine (required to maintain correct rear suspension geometry). Once this is done, you will have the carb inlet bell in the proper position to start
the fitment process. Next, you will have to reface the airbox to relocate the airboot in order to clear the shock spring and reach the carb bell. Refacing consist of cutting the front of the airbox off and replacing it with a 1/8" thick 6061 Aluminum
plate. The new faceplate alows you to relocate the boot to the left and up or down a bit to achieve the optimum angle. That 98 boot you have should work with a long body Keihin.
Anyway, I could write a book about this, but I already have so I won't do it again. If you're interested, check out my build post.
Good luck with it.
Unfortunately im not sure what year air boot i have so its no real gauge to go off for further adjustments, ill just have to buy a 99 boot n see how close that fits.
But my carb is super close to the shock spring and boot also rubs on the frame. So thinking i will have to pack out reeds with a v3 and go a 99boot like you have suggested to others. (seen some people using kx boots??) Hoping this will give just enough clearance to push boot back and carb to clear the spring (or thinner shock spring?). Refacing with a plate wont be to hard hopefully i can get it close with the 99 boot with engine clocked to suit cs. Wish i had of read through your build before i started would have done things a bit different, as i don't think i bought a long carb just one more thing to make it hard for me.
My aim for this build was to build it for less then four stroke engine rebuild and have a much older older stock motor making more power then a new stock bike. After the drama with this 09 four stroke motor i will never own another 4stroke. Had the suspension dialled in on this bike by Charly costanzo (from Auz worked in the states for factory honda for a bit) so even if this build is a mega head ache it will be worth it when its done. Cheers, Ben.
If it helps. The Eibach rear shock spring on my RMZ is "thinner" than the stock spring. Wouldn't have a clue if it's the same with the CRF though sorry. Just sayin.
I have the opposite problem on my RM265 AF, I need a bit more clearence for the carby. JFYI, the Lectron "Shorty" carby is 10mm longer than my 06 RM 250's stock carby.
The Lectron is also extremely fuel efficient. I get 4 hours+ ride time on my 144AF with a 7 litre tank. Only carby I'll be running on any 2T's in the future. I'm a very happy customer. Again, just sayin.
My frame rails are angled down, and straight . I didn't do my frame (I don't have the tools, or workshop. Luckily, I do have a lounge room ), I specifically asked the bloke who did to bring the cradle up under the engine as much as possible, like the steel frame. He didn't .
Being that I ride off road, and my mates don't mind the odd log hop or 100. I'm slightly stressed about it, I'll bottom out on the frame if the speed is slow, plus it looks like crap. It'd be fine on an MX track, ust a pitty I'm too old for that these days.
I bought a carbon bash plate to try and hide it . I'm big on looks and when I'm looking at the bike I can't help but focus on the frame rails .
Anyway, I'm enjoying your build. I had a new 89 CR 250. Last 2T Honda I had, but I really liked it. She was a hole shot weapon.
Just curious. This question is for Dogger as well, and any other Honda fanatics. The 96 model CR250 engine and frame I have here ATM are reallly light, especially the engine, is that normal? I'd say both are lighter than my RM125 engines and frames. Swing arm as well. My RM 250 frame and engine, 06, are heaps heavier.
I ask because the bike I have here is supposed to be Mike Jones's Ex Factory Honda bike from the states. To be completely honest, I didn't even know he rode for Honda. To me, the bike looks "normal". Everything is just very light, actually, and tight. The suspension (Which I don't have ATM), is factory. That has been confirmed.
Last edited by 2 stroke bloke; 09-08-2016 at 03:16 PM.
Unfortunately for you since you have already bought your donor, a 2005 airbox also means a 2005 subframe and seat. Keep in mind, using a twin pipe subframe and airbox means you also get to sport twin pipe side panels only there isn't anything under the Left side panel bulge. You will have to decide if those extra parts are worth the expense.
As far as "clocking" the engine, the only thing you should be concerned with is matching the CRF CS to swingarm pivot bolt angle. You can't do anything about the distance per se since that dimension is locked in by the pivot bolt cavity cast into the engine case. The angle is the important variable and controlled by tilting the engine up or down. When at the correct angle, the suspension will work as designed in that the upper and lower rollers will snatch at the correct swingarm angles. Don't fall for the "rotating mass" BS. Simply swapping a two stroke engine for a four stroke engine significantly reduces what little rotating mass there is to begin with and more importantly, lowers the bulk of it to the bottom of the frame (no cams or valve train).
Speaking from experience, your airboot will fit and clear the shock spring as long as you take these steps: 97-99 air boot, Aluminum face plate, 92-96 intake manifold, Boyesen or VForce reed, long body Keihin. For the pipe, I used a 2000 CR250 pipe because I had a 2000 CR250 engine. The pipe bolted right up using 2002-07 front and rear strap mounts. I can't tell you anything about fitting an 89 pipe. The silencer is another story and you will have to decide how to crack that one. I ended up cutting the inlet pipe off and re-welding it to the can to make it fit.
Anyway, remember my "can of worms" comment? There's a reason you don't see this combination very often.
il order air boot n parts as you have listed cheers for that saves so much time and money .
For the silencer i was thinking about running the 89 model shape for the old school look to match the old motor. (obviously have to cut n weld to work). Think i will need a new pipe as well as its seems to be kinked inward and i dont want to make all the mounting points to suit a bent pipe. I will be over budget for the plan to do this for less then a 250f rebuild but it will be worth it. il have to find out what year model pipes still work on a 89 model motor might open up my choice of pipes a bit.
Small update, just ebaying parts for the build. Wont be home til jan 15 till i get back from dubai/europe to auz so just nutting out bits and pieces to order so everything is there when i get home.
Parts left to get,
air box adaptor plate (or fab it)
wiring for motor
coil bracket (or fab it)
possibly new pipe
different radiator hoses
fab radiators to suit
fab engine mounts
million more small things to chase up but thats a start for now.
Been trying to figure out the length difference from a short carb to a long carb? 10mm? as i think i might have the short carb.
anyone on here had much to do with the 89 model motor? just wondering what best after market pipe to go with. bikes only going to be ridden on mx track. cheers
so im finally back in aus and working on the bike again,
had all my parts here ready to go but still having dramas with the air boot to subframe distance and angle working.
i used a 95 intake boot
97 air boot
plus i made a 12mm aluminium spacer between the reed bloock and intake and its still coming up short of being able to bolt to the air box and clear the shock.
only thing i can think of is my carb is really short or the 89 model motor is way different. any way its not fitting up. any other air boot/carb suggestions?
image upload without registration[/IMG]
---------- Post added at 02:06 PM ---------- Previous post was at 02:04 PM ----------
some update pics of where im at with the build atm. still trying to sort out air boot. but once that is sorted it should come together quickly.
---------- Post added at 02:11 PM ---------- Previous post was at 02:06 PM ----------
carb spacer i made up to try and get the boot i had to work. But still going to need a different boot. Even with vforce reeds. The boot i had is a kz3f off a 1997 doesnt work.
here is a bit of an update where i am up to at the moment.
After all the cr boots being to short i was lucky enough to get a kx250 boot locally off a member on this site. (cheers mate you are legend) it was about 30mm longer then cr boots so fitted length ways cleared around the shock nicely.
Ive been working away atm so havent had a great deal of time to put into the build. But managed to make an adapter plate, fit and seal the air boot today. Now that hurdle is out of the way the rest of the build is just brackets, bending and welding pretty easy really.
if anyone has some 90' radiator fittings or old radiators kicking about let me know chasing two bends thanks.
photos are pretty self explanatory.
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