Full Tilt CR250 Build - MXA Two Stroke Hall of Fame

blackdiamond
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blackdiamond 1/3/2016 11:04pm
1/3/2016 11:04pm
Awesome Johnson wrote:
Almost forgot, killer fuel shut off valve. This build is gold! Might as well change the thread name again to the 3rd gen cr250 blue print...
Almost forgot, killer fuel shut off valve. This build is gold! Might as well change the thread name again to the 3rd gen cr250 blue print cause that's what it is. To me this is right up there or even past chadillacs 2012 crf250(or was it a 450?) with the sx250 motor swap and all the ti shit for days. Good stuff! How long have you been planing, gathering and machining parts for this build?
I have been tinkering with it on and off for about a year. I had a few injuries that put me on the bench for awhile so the timing was good.
blackdiamond
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blackdiamond 1/3/2016 11:07pm
1/3/2016 11:07pm
ocscottie wrote:
Better yet, let our own ML512 do a full test / feature on it for our homepage. Michael knows his stuff! That would be the perfect...
Better yet, let our own ML512 do a full test / feature on it for our homepage. Michael knows his stuff! That would be the perfect bookend for this thread. Cool
I would be down with that, I have seen his bike tests and reviews and he is very analytical. He could probably appreciate the bike more than most.
Awesome Johnson 1/3/2016 11:12pm
1/3/2016 11:12pm
Well I hope your all healed up and ready to rip as soon as this is done. It would be pretty hard to look at it finished and not be able to ride it.
blackdiamond
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blackdiamond 1/3/2016 11:17pm
1/3/2016 11:17pm
This pic gives you an idea how thin and light the Martin Honda HRC wheel spacer is. They literally weigh about the same as a couple of good sized potato chips.



The Shop

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Bearuno
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Bearuno 1/4/2016 7:15am
1/4/2016 7:15am
You are going for broke on weight, so, check various late model 4t kick start levers. They are often a pound or two lighter than older 2ts, as so much effort has gone into lightening the ancillaries on 4ts. 125 levers may also be found to fit

I used a CRF 450 lever on my 500, before I went to an ultra short Gas Gas lever ( non bendy knees, a short lever means less leg lift, plus a quicker rotation of the shaft). As I was always concerned that the much smaller pivot post - 13mm as against 19mm on the 500 knuckle- of the Gas Gas lever might break, I found that an 89 CR 125 lever fitted onto the CRF 450 Knuckle. So packed it as a spare, but the GG lever has held up for many years now, though, that's probably down to the auto decompressor I have on the 500, and the fact that the short lever, when it contacts the footpeg, has no overhang past the footpeg, so it has no 'fulcrum' effect on the lever, nor the cases. A short lever may also help keep your now machined out KS shaft from spiral breakage - I've seen quite a few break over the years when people have done your litening trick.
Reefer Sutherland 1/4/2016 7:18am
1/4/2016 7:18am
ocscottie wrote:
Better yet, let our own ML512 do a full test / feature on it for our homepage. Michael knows his stuff! That would be the perfect...
Better yet, let our own ML512 do a full test / feature on it for our homepage. Michael knows his stuff! That would be the perfect bookend for this thread. Cool
Should get someone who actually likes two-strokes to ride it.
philG
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philG 1/4/2016 7:42am
1/4/2016 7:42am Edited Date/Time 1/4/2016 7:45am
Awesome Johnson wrote:
I see the name of the thread has evolved like everything else going on here. I like what you did with the kick start lever and...
I see the name of the thread has evolved like everything else going on here. I like what you did with the kick start lever and agree. Lots of fat on them. Care to elaborate more on the gun drilling process as in how you did it? I'm more of a picture guy, you know, a picture is worth 1000 words type thing. Keep up the good work!
Be careful when Gundrilling stuff to save weight... the way a solid behaves compared to a tube under this type of load is a big issue. Removing the middle reduces the ability of the shaft to absorb twist , so it will spiral fail as a tube in a way a much smaller solid will not. Its all about cross sectional area and its ability to resist twist before failure.

The last Vertemati's had a solid shaft for the forward Kick on the racebikes, but the road units had a hollow tube that failed , especially when it was cold. They recalled the lot .

The shaft will be hardened on the OD to give it wear resistance , but the inside will be soft to give it some flexibility .

Take out the middle, and you are left with the brittle outer shell.

There is a reason the OEM's don't do this already , because it would save a bunch of weight, but in applications where shafts are hollow, there is a big increase in size , to get back the cross sectional area.

Here is a simple calculator to show the effect

http://www.amesweb.info/Torsion/TorsionalStressCalculator.aspx
blackdiamond
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blackdiamond 1/4/2016 7:54am
1/4/2016 7:54am
philG wrote:
Be careful when Gundrilling stuff to save weight... the way a solid behaves compared to a tube under this type of load is a big issue...
Be careful when Gundrilling stuff to save weight... the way a solid behaves compared to a tube under this type of load is a big issue. Removing the middle reduces the ability of the shaft to absorb twist , so it will spiral fail as a tube in a way a much smaller solid will not. Its all about cross sectional area and its ability to resist twist before failure.

The last Vertemati's had a solid shaft for the forward Kick on the racebikes, but the road units had a hollow tube that failed , especially when it was cold. They recalled the lot .

The shaft will be hardened on the OD to give it wear resistance , but the inside will be soft to give it some flexibility .

Take out the middle, and you are left with the brittle outer shell.

There is a reason the OEM's don't do this already , because it would save a bunch of weight, but in applications where shafts are hollow, there is a big increase in size , to get back the cross sectional area.

Here is a simple calculator to show the effect

http://www.amesweb.info/Torsion/TorsionalStressCalculator.aspx
That totally make sense. Both of the shafts we lightened were already hollow, I just opened up the inside diameter a bit, similar to what I have seen in some of the four stroke engines.
ML512
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ML512 1/4/2016 8:09am
1/4/2016 8:09am
ocscottie wrote:
Better yet, let our own ML512 do a full test / feature on it for our homepage. Michael knows his stuff! That would be the perfect...
Better yet, let our own ML512 do a full test / feature on it for our homepage. Michael knows his stuff! That would be the perfect bookend for this thread. Cool
blackdiamond wrote:
I would be down with that, I have seen his bike tests and reviews and he is very analytical. He could probably appreciate the bike more...
I would be down with that, I have seen his bike tests and reviews and he is very analytical. He could probably appreciate the bike more than most.
Email sent.
ML512
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ML512 1/4/2016 8:11am
1/4/2016 8:11am
Reefer Sutherland wrote:
Should get someone who actually likes two-strokes to ride it.
I like two-strokes... But I like four-strokes more.... Personal preference.
activeMX
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activeMX 1/4/2016 8:35am
1/4/2016 8:35am
blackdiamond wrote:
[img]https://p.vitalmx.com/photos/forums/2015/12/31/117658/s1200_CAM00188.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2015/12/31/117659/s1200_20151218_221926.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2015/12/31/117660/s1200_20151218_223534.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2015/12/31/117661/s1200_CAM00189.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2015/12/31/117662/s1200_20151120_160102.jpg[/img]










Who did the anodizing on your engine cases and fork lugs? I'm interested in doing this to my 450.
Mit12
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Mit12 1/4/2016 9:48am
1/4/2016 9:48am
philG wrote:
Be careful when Gundrilling stuff to save weight... the way a solid behaves compared to a tube under this type of load is a big issue...
Be careful when Gundrilling stuff to save weight... the way a solid behaves compared to a tube under this type of load is a big issue. Removing the middle reduces the ability of the shaft to absorb twist , so it will spiral fail as a tube in a way a much smaller solid will not. Its all about cross sectional area and its ability to resist twist before failure.

The last Vertemati's had a solid shaft for the forward Kick on the racebikes, but the road units had a hollow tube that failed , especially when it was cold. They recalled the lot .

The shaft will be hardened on the OD to give it wear resistance , but the inside will be soft to give it some flexibility .

Take out the middle, and you are left with the brittle outer shell.

There is a reason the OEM's don't do this already , because it would save a bunch of weight, but in applications where shafts are hollow, there is a big increase in size , to get back the cross sectional area.

Here is a simple calculator to show the effect

http://www.amesweb.info/Torsion/TorsionalStressCalculator.aspx
blackdiamond wrote:
That totally make sense. Both of the shafts we lightened were already hollow, I just opened up the inside diameter a bit, similar to what I...
That totally make sense. Both of the shafts we lightened were already hollow, I just opened up the inside diameter a bit, similar to what I have seen in some of the four stroke engines.
The biggest problem with drilling shafts is caused by the machinists and his ability to make a hole with out stress risers. If you grind and polish the inside to eliminate all stress risers the shaft will be plenty durable. Up keep will be a little more work if the shaft is exposed to the elements as any pitting from rust will cause a failure.
neverwasfastenuf 1/4/2016 10:48am
1/4/2016 10:48am Edited Date/Time 1/4/2016 10:49am
ML512 wrote:
I like two-strokes... But I like four-strokes more.... Personal preference.
You meant to say so far, correct? Wink
ML512
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ML512 1/4/2016 11:04am
1/4/2016 11:04am
neverwasfastenuf wrote:
You meant to say so far, correct? Wink
Nope, sorry... I like four-strokes and air forks... burn me at the stake! I like two-strokes and springs forks as well though...
ginger969
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ginger969 1/4/2016 11:22am
1/4/2016 11:22am
wow...this thing is spectacular! i don't know if I could come to actually riding one that nice and one-off haha
ginger969
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ginger969 1/4/2016 11:24am
1/4/2016 11:24am
neverwasfastenuf wrote:
You meant to say so far, correct? Wink
ML512 wrote:
Nope, sorry... I like four-strokes and air forks... burn me at the stake! I like two-strokes and springs forks as well though...
hahaha Silly
DoctorJD
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DoctorJD 1/4/2016 11:25am
1/4/2016 11:25am
ML512 wrote:
Nope, sorry... I like four-strokes and air forks... burn me at the stake! I like two-strokes and springs forks as well though...
YOU CAN'T LIKE BOTH, PICK A SIDE!!

Wink
Nom DeGuerre
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Nom DeGuerre 1/4/2016 11:38am
1/4/2016 11:38am
the only word that comes to mind for this build is "EPIC"... holy hell, this is one fantastic thread and bike.

Pit Row

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neverwasfastenuf 1/4/2016 11:43am
1/4/2016 11:43am
ML512 wrote:
Nope, sorry... I like four-strokes and air forks... burn me at the stake! I like two-strokes and springs forks as well though...
DoctorJD wrote:
YOU CAN'T LIKE BOTH, PICK A SIDE!!

Wink
Smile
smezmx
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smezmx 1/4/2016 12:20pm
1/4/2016 12:20pm
Nice.super cooper!
Markopolo400
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Markopolo400 1/4/2016 12:37pm
1/4/2016 12:37pm
ML512 wrote:
I like two-strokes... But I like four-strokes more.... Personal preference.
WRONG ANSWER
blackdiamond
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blackdiamond 1/4/2016 3:21pm
1/4/2016 3:21pm
activeMX wrote:
Who did the anodizing on your engine cases and fork lugs? I'm interested in doing this to my 450.
Temecula Quality Plating, ask for Duke.

951-296-9568
blackdiamond
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blackdiamond 1/4/2016 3:26pm
1/4/2016 3:26pm
Mit12 wrote:
The biggest problem with drilling shafts is caused by the machinists and his ability to make a hole with out stress risers. If you grind and...
The biggest problem with drilling shafts is caused by the machinists and his ability to make a hole with out stress risers. If you grind and polish the inside to eliminate all stress risers the shaft will be plenty durable. Up keep will be a little more work if the shaft is exposed to the elements as any pitting from rust will cause a failure.
The I.D. is extremely smooth and they are bathed in oil. I am not even close to being worried about any of these parts failing after seeing some of the internals of the newer four strokes. Some of the water pump drive gears, counter balancers, etc. in the latest thumpers look like they came from a sewing machine instead of a dirt bike compared to the older two strokes.
Underground 1/4/2016 5:21pm
1/4/2016 5:21pm
ocscottie wrote:
Did you guys see this one? WOW!!! http://www.vitalmx.com/community/Mike-P,44902/setup,47739 [img]https://p.vitalmx.com/photos/users/44902/setup_checks/47739/photos/15423/s1600_s1200_20151226_173232_resized.jpg?1451437453[/img]
Did you guys see this one? WOW!!!

http://www.vitalmx.com/community/Mike-P,44902/setup,47739

Love those model RM's
Steve 396
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Steve 396 1/4/2016 6:06pm
1/4/2016 6:06pm
I have never been a 2 stroke fan but......... Wow, what a build this is. Attention to detail is over the top and I love it. Great job BD, I am a huge fan of this!
blackdiamond
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blackdiamond 1/4/2016 10:52pm
1/4/2016 10:52pm
Awesome Johnson wrote:
Almost forgot, killer fuel shut off valve. This build is gold! Might as well change the thread name again to the 3rd gen cr250 blue print...
Almost forgot, killer fuel shut off valve. This build is gold! Might as well change the thread name again to the 3rd gen cr250 blue print cause that's what it is. To me this is right up there or even past chadillacs 2012 crf250(or was it a 450?) with the sx250 motor swap and all the ti shit for days. Good stuff! How long have you been planing, gathering and machining parts for this build?
blackdiamond wrote:
I have been tinkering with it on and off for about a year. I had a few injuries that put me on the bench for awhile...
I have been tinkering with it on and off for about a year. I had a few injuries that put me on the bench for awhile so the timing was good.
I had a hand in building the bike you mentioned in this post. In fact, when the owner sold the bike and moved to AZ, I bought a few of the trick pieces from him because they were such a pain in the ass to create in the first place and I had a lot of time in them. I knew I might be able to use them in the future. That was a cool project for sure and if you look closely you will see that the triple clamps are the same in that build. I ended up with the DLC coated Titanium swingarm pivot from that bike as well.
ML512
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ML512 1/5/2016 12:55am
1/5/2016 12:55am
Markopolo400 wrote:
WRONG ANSWER
I like dirt bikes?
philG
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philG 1/5/2016 2:15am
1/5/2016 2:15am
Mit12 wrote:
The biggest problem with drilling shafts is caused by the machinists and his ability to make a hole with out stress risers. If you grind and...
The biggest problem with drilling shafts is caused by the machinists and his ability to make a hole with out stress risers. If you grind and polish the inside to eliminate all stress risers the shaft will be plenty durable. Up keep will be a little more work if the shaft is exposed to the elements as any pitting from rust will cause a failure.
blackdiamond wrote:
The I.D. is extremely smooth and they are bathed in oil. I am not even close to being worried about any of these parts failing after...
The I.D. is extremely smooth and they are bathed in oil. I am not even close to being worried about any of these parts failing after seeing some of the internals of the newer four strokes. Some of the water pump drive gears, counter balancers, etc. in the latest thumpers look like they came from a sewing machine instead of a dirt bike compared to the older two strokes.
While I agree that they have had to pay a lot of attention to detail in weight saving and miniaturizing parts on the new four bangers , they will have been designed and processed with that in mind.

Parts are machined and heat treated relative to what the need to be when they are finished.. I have seen instances where sizes have been on extremes pre Heat Treatment , and the subsequent processes have removed the hardened outer case leaving a part that failed after a few KM .

blackdiamond
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blackdiamond 1/5/2016 9:20am
1/5/2016 9:20am
Bearuno wrote:
If you can provide a CR500 unit, you've probably got a customer in me. I've tried the OEM CR250 set up, not been that impressed (and...
If you can provide a CR500 unit, you've probably got a customer in me. I've tried the OEM CR250 set up, not been that impressed (and they are getting rather expensive) and VForce. The 'Z' set up really impresses me, in the various fitment reports I've read on them, when used on other bikes.

I held back on naming the company, as I thought you might be in business with them and didn't want to provide an avenue for people to bypass you in your market - it's refreshing to see someone freely put out the name / contact of a product they are involved with.

I've been after a better ignition for my 500 for many years - for easier starting (I'm on crutches / a walking stick much of the time nowadays) and smoother power, mainly. I've been very interested in the Z, but never followed them up, mainly due to my lack of interest in programming and set up of electronics - I've far too much on my plate with my own suspension work and frame making, and would rather deal with someone who has real knowledge of the product. If I can get a pre-programmed kit, with a variety of setting options, you've got a customer, after the holiday period. I'll contact you probably in February.
What year CR500 do you have?

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