LIVENDIESMOKINS' 4TH GEN CRF250R 500/AF BUILD

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 6th, 2008, 12:53 pm

The build has begun. I did as ALISOBOB suggested and notched the frame rail to avoid the engine case clearance issue, and to rotate the engine downward in the front. This also allowed me to relocate the Y a little lower to avoid rad clearance. I discovered that the right side engine spacer is the correct length and the left one is 5mm short. I added a 5mm spacer to the left side and she is aligned perfectly. The bike had an Acerbis 2.9 gallon tank, which after testing, would not accept plastic welding. (good thing I tested before cutting) I did, however, heat it and push it in. The tank issue was totally solved. It now has lots of clearance and it still holds 2.7 gallons of fuel. I think I can change the plug without removing the tank. When my tubing arrives, I'll complete the assembly and have her welded. More pics to come.

britincali · Post by **britincali** » January 6th, 2008, 1:07 pm

Nice work

If you get the short plug that will help you with swaps even more

TJC510 · Post by **TJC510** » January 6th, 2008, 2:31 pm

looking good. its nice to see someone else doing a gen 4 also.

ive been thinking about buying the acerbis tank, but was wondering about clearance. looks like it fits quite nice.

HrcRacing · Post by **HrcRacing** » January 6th, 2008, 5:32 pm

Man, that looks really good. If you don't mind, can you tell me more about your compression release valve?

Thanks.

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 7th, 2008, 6:12 am

That is a valve type compression release. They were common in the 70's because some bikes had 2 spark plug holes. I do not use it for starting, other than maybe clearing a flooded engine. Its' main purpose is braking. I live in the hills of eastern tennessee. As you know, there are lots of times that you need your right foot off the peg in a turn or a steep narrow singletrack downhill. This is where the release shines. It provides smooth braking, allowing the rear tire to continue to turn without locking.

I bought some several years ago. The package doesn't have a manufacturer name but the model # is CRK-0813. It comes with the release, cable, and lever.

Installation isn't bad. Just drill a 7/8" hole thru the head in your desired location. I followed the same angle as the plug, slightly to the left. Inside the head, chamfer the hole a bunch to allow for the weld (The dome is very thick). Turn a sleeve on a lathe that will have a slight press fit into the hole. Before removing from the lathe, drill the ID for a spark plug tap (14mm). Do not tap it until it is welded in. After pressing in (just tight enough to not fall out ) allow about 3/16" to 1/4" sticking out on top. Inside, shape the sleeve to the contour of the bowl/squish band, leaving approx 1/8" protruding (this will flatten out when the welder does his thing).

Find a GOOD welder and have it welded in, inside and out. Note: DO NOT try to grind the weld inside the head, as aluminum welding will likely have air pockets and a coolant leak could occur. NOT GOOD. A good welder can flow the weld smoothly.

This may sound nuts, and physically look like it would impede engine performance, but a friend and I have done 7 of these over the years with no problems. The first ones have been running for over 10 years

After completion, check the head for warpage by placing the head surface on a piece of 220 grit sandpaper that is on a thick, smooth, flat piece of glass or a machinist stone table. Lubricate with WD40 and move in a circular motion. Check the head surface for sanding marks over the entire surface. Continue to sand until the surface is uniform.

I've never had one warp from the welding, but have bought used heads to modify that were already warped. Nevertheless, its' a good idea to check it.

This process is really pretty simple and the results are awesome........

Post by **AlisoBob** » January 7th, 2008, 6:39 am

LIVENDIESMOKIN wrote:Lubricate with WD40 and move in a circular motion.

A " Figure 8" motion takes into consideration your push-pull hand movements and providers better results.

Whats with the rubber bumper on the kick starter?

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 7th, 2008, 6:52 am

ALISOBOB, good thought. A friend made that for me a long time ago. It basically just cushions the kicker when its' returned. It made my friend happy, so what the heck.

Btw, You may already know, but the following link is to a wide ratio kit.

http://www.madmanengineering.com/wideratio.htm

HrcRacing · Post by **HrcRacing** » January 7th, 2008, 9:58 am

Ok, I'm a bit dense here and don't mean to hi-jack your thread, but can you describe how you're using this on downhills a little more? I mean, are you pulling in a decompression lever?

Also, do you know anyone who sells this now?

Thanks man!

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 7th, 2008, 10:45 am

The decompression lever is mounted on the left side of the bars. You can even connect the cable to the little hot start lever on a CRF perch. You pull the lever for braking.

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 7th, 2008, 12:39 pm

Just a quick google search resulted in the following link

http://www.cyclewareables.com/pages/am_ ... e_kits.htm

A friend had a small parts shop and he ordered them for me. I ordered enough to do me for as long as I can ride. He has since moved out of state. I'll contact him and find out where he ordered them from.

HrcRacing · Post by **HrcRacing** » January 7th, 2008, 1:51 pm

You learn something new everyday. I had lunch with my buddy today and he was explaining how that works for breaking.

I've been riding/racing for 25 some years and your mention of it was the first I ever heard of it.

LIVENDIESMOKIN wrote:A friend had a small parts shop and he ordered them for me. I ordered enough to do me for as long as I can ride. He has since moved out of state. I'll contact him and find out where he ordered them from.

Thank you very much!

Exnav · Post by **Exnav** » January 7th, 2008, 2:20 pm

Sort of a "Jake Brake" for 5 hundy's.

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 15th, 2008, 9:44 am

Looks like she's ready for welding. All the metal fab is complete. All pipe, silencer, coil, module, and overflow brackets are ready. My FMF pipe (not shown) only required minor angle tweaking and increase the factory clearance dent at the reed cage. The Acerbis tank fits wonderfully after heating and pushing in the bottom. It still holds 2.7 gallons (lost .2-.3 gal). I did not have to modify the hoses or spigots at all. Saturday is the planned weld date. I'll post more pics after welding and assembly begins. I can hardly wait to unleash her!

Post by **AlisoBob** » January 15th, 2008, 12:41 pm

Toss up some photos of your head stay...

....nice work. Your tank clearence is unreal. I'd sell Brits left nut on ebay for clearence like that.

Where is the coil going???? Stick it under the right side panel like I did, so all your buddies can stare at your 3' coil wire.....

sabreguy · Post by **sabreguy** » January 15th, 2008, 5:50 pm

Is this a 450 or 250 frame?

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 15th, 2008, 7:50 pm

It's a 2004 CRF250R chassis. I'll post a pic of the head stay tomorrow. The coil is going to be mounted on the top side of the subframe rail that the silencer is mounted to, behind the air box. ( a little more rearward than Alisobobs') The coil wire will be a long one. The ignition module will be mounted to a bracket that will be welded to the subframe crossbar at the rear of the air box. The module will essentially be mounted on its' side with the screws going thru the rear of the air box into the new bracket. When the welding is completed, and assembly begins, I'll post pics of these small items.

Post by **AlisoBob** » January 15th, 2008, 8:02 pm

LIVENDIESMOKIN wrote: The coil wire will be a long one.

SWEET!!!! The longer , the better.... ( or so my wife says.....)

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 16th, 2008, 10:19 pm

This is the head stay that I whipped up at home. At the frame mount, my tank only has enough clearance for 1/4" material on each side.

I'm currently working on the airbox/boot configuration, as she's ready for welding this weekend.
I ended up mounting the coil below the head stay, on the bottom of the frame center section. The cdi will be mounted between the radiators, on the downtube like the steelie. I'm using the bracket from the crf250 that mounted the cdi to the steering head. Just drill and tap a couple of holes in the downtube and she's mounted.

LIVENDIESMOKIN · Post by **LIVENDIESMOKIN** » January 26th, 2008, 9:43 pm

Sorry I didn't post pics as I assembled it. After 5 days at the welder, I got her back. I was like a kid at christmas. Took a vacation day from work and worked 16 hours on her. It was worth it. Now, 2 days later, I took her for a spin around the yard. Who needs a lawn ariator when you have a cr500!!!

Still have to install the skid plate and steering damper before thrashing her.

Thanks Bob, for inspiring me, motivating me, and sending the tubing.......

I saved a lot of cash over a SH, and I know its' built well and will last.....

FYI, The 2000 CR250 air boot worked perfectly. It uses a stock cr500 inner frame, filter, and outer frame. Just order the 2000 CR250 boot ($30.00).

Post by **AlisoBob** » January 27th, 2008, 8:01 am

LIVENDIESMOKIN wrote:
Thanks Bob, for inspiring me, motivating me, and sending the tubing.......

FYI, The 2000 CR250 air boot worked perfectly. It uses a stock cr500 inner frame, filter, and outer frame. Just order the 2000 CR250 boot ($30.00).

Thanks for the tip!!!

Post by **AlisoBob** » January 27th, 2008, 8:03 am

Can you post up some good photos of that tank, and what it took to fit it?

mxracr121 · Post by **mxracr121** » January 27th, 2008, 10:27 am

One fast build! Looks good!

HrcRacing · Post by **HrcRacing** » January 27th, 2008, 11:27 am

Man that was quick. Congratulations and it looks great!

2weelz · Post by **2weelz** » January 28th, 2008, 9:37 am

So the '00 boot is different from the '01 boot...even though they are the same bikes?

dannygraves · Post by **dannygraves** » January 28th, 2008, 9:39 am

'00 cr250 had a Keihin carb, the '01 had a mikuni, so they changed the intake boot between those years. plus the motor and trans saw a crap load of internal changes. The '01 cr250 is still a favorite for a lot of freestylers. way more power than the '02+ and still a really good frame and suspension setup.

BannedCR500Riders.com

LIVENDIESMOKINS' 4TH GEN CRF250R 500/AF BUILD

LIVENDIESMOKINS' 4TH GEN CRF250R 500/AF BUILD