Author Topic: IT/YZ 250D pre78 project  (Read 19866 times)

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Offline head

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Re: IT/YZ 250D pre78 project
« Reply #30 on: February 18, 2013, 05:31:48 pm »
Yamaico put me onto this.You need to get the right steel (1mm CA2SE) which is soft malleable iron and really easy to roll. Bought a sheet from Metal Land for about $70. I hand roll them around a old fork tube and a 1/2 bar hose clamped to fork tube, also use a soft face hammer for edges.

Offline Ted

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Re: IT/YZ 250D pre78 project
« Reply #31 on: February 18, 2013, 06:40:48 pm »
Show us the 465
81 YZ 465 H   77 RM 125 B

Offline Slakewell

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Re: IT/YZ 250D pre78 project
« Reply #32 on: February 18, 2013, 06:55:01 pm »
Yamaico put me onto this.You need to get the right steel (1mm CA2SE) which is soft malleable iron and really easy to roll. Bought a sheet from Metal Land for about $70. I hand roll them around a old fork tube and a 1/2 bar hose clamped to fork tube, also use a soft face hammer for edges.

Otherwise known as low carbon steel or Panel steel.
Current bikes. KTM MC 250 77 Husky CR 360 77, Husky 82 420 Auto Bitsa XR 200 project. Dont need a pickle just need to ride my motorcickle

Offline head

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Re: IT/YZ 250D pre78 project
« Reply #33 on: February 18, 2013, 09:18:45 pm »
The 465 is just lots of parts scattered around my sheds. One at a time Ted.

Offline head

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Re: IT/YZ 250D pre78 project
« Reply #34 on: February 18, 2013, 09:21:44 pm »
The painting of plastic tanks is hit and miss. I have done one 3 years ago and it is still perfect. The next one I did flaked of in a month. Plastic primer, 2k primer and 2k paint. Hope this one lasts.

Offline head

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Re: IT/YZ 250D pre78 project
« Reply #35 on: March 03, 2013, 06:16:31 pm »
Finally finished pipe, bike ready for a test ride when all this rain stops. Started it up though and it sounds OK, I am running the IT250 ignition which is a large outer rotor type. Not sure if I am going to be happy with this and would be interested in a YZ250 C, D, or E inner rotor ignition. If any one has one for sale or swap for IT ignition, it would help me out heaps. Here are final pics of Pipe fitted up.

Offline Lozza

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Re: IT/YZ 250D pre78 project
« Reply #36 on: March 03, 2013, 06:27:56 pm »
What did you use to design the pipe?
Jesus only loves two strokes

Offline head

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Re: IT/YZ 250D pre78 project
« Reply #37 on: March 03, 2013, 06:37:19 pm »
Just the formulas out of Graham Bells book, with a few educated guesses.

Offline Paul552

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Re: IT/YZ 250D pre78 project
« Reply #38 on: March 03, 2013, 07:27:05 pm »
Wow that pipe looks nice.
What is the book you refer to?
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline yamaico

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Re: IT/YZ 250D pre78 project
« Reply #39 on: March 03, 2013, 07:58:54 pm »
You've done a great job on that pipe Neil, well done.

Offline head

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Re: IT/YZ 250D pre78 project
« Reply #40 on: March 03, 2013, 09:28:39 pm »
TFR it is Two-Stroke Performance Tuning by Graham Bell

Offline head

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Re: IT/YZ 250D pre78 project
« Reply #41 on: March 03, 2013, 09:31:06 pm »
Thanks Pete, but it is your influence that got me game enough to try these things.

Offline firko

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Re: IT/YZ 250D pre78 project
« Reply #42 on: March 03, 2013, 09:48:09 pm »
Quote
You've done a great job on that pipe Neil, well done.
I agree with Pete, great pipe and another great project Neil. This bike to me represents the DIY attitude that makes our side of the offroad dirt scene so unique. With guys like you and Pete building bikes that aren't cookie cutter copies of everyone elses bikes, the sport's just that wee bit more interesting ;).
« Last Edit: March 03, 2013, 09:50:14 pm by firko »
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline Lozza

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Re: IT/YZ 250D pre78 project
« Reply #43 on: March 04, 2013, 09:43:52 pm »
Just the formulas out of Graham Bells book, with a few educated guesses.

What tuned length did you arrive at as it looks mighty short.
Jesus only loves two strokes

Offline head

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Re: IT/YZ 250D pre78 project
« Reply #44 on: March 06, 2013, 12:19:21 am »
It was 786mm