RZ/RD 350 & Misc. 2-Stroke Tech BBS

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 Post subject: Re: Flywheel lightening
PostPosted: Sat May 19, 2018 10:35 pm 
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Joined: Fri Oct 03, 2003 11:11 pm
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Location: Southern Ontario, Canada
Why dick about modifying 30 year old motorcycles? Find and buy a faster motorcycle, for a genuine improvement?
There are plenty available. Not free, but then nothing new ever is.

....unless you enjoy dicking around with old motorcycles, then carry on. :smt002


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 Post subject: Re: Flywheel lightening
PostPosted: Sun May 20, 2018 5:09 am 
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Location: Wellington New Zealand
Hahaha.
Thanks for posting. :smt003

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 Post subject: Re: Flywheel lightening
PostPosted: Sun May 20, 2018 6:29 am 
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A quick calculation puts the difference in inertia of a 2 mm cut to be about -16%, not bad for free. [smilie=cool.gif]


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 Post subject: Re: Flywheel lightening
PostPosted: Sun May 20, 2018 11:16 pm 
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Location: vancouver
RuZty wrote:
Why dick about modifying 30 year old motorcycles? Find and buy a faster motorcycle, for a genuine improvement?
There are plenty available. Not free, but then nothing new ever is.

....unless you enjoy dicking around with old motorcycles, then carry on. :smt002


Being a hapless Dick are we?

It's possible to buy an Ignitech or Dynapower flywheel/ stator assly. Designed to fit the Yama 350 engine
Which is Purpose designed to be Lighter for performance reasons.
Shaving a few mm off of the oem Yama flywheel is V close to pointless.


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 Post subject: Re: Flywheel lightening
PostPosted: Fri Jun 08, 2018 12:56 am 
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Location: Vancouver Is. Canada
Done. Be interesting to see what the result will be on the throttle. Created a woodruff key in an inverted 'T' shape to tightly fit the worn/widened channel in the flywheel to fit tight.


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 Post subject: Re: Flywheel lightening
PostPosted: Sun Jun 10, 2018 4:20 am 
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Joined: Mon Mar 03, 2014 8:44 pm
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Location: Alberta, Canada
Keep us posted.

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 Post subject: Re: Flywheel lightening
PostPosted: Fri Aug 10, 2018 2:25 pm 
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Location: Calgary, Alberta
hondaror wrote:
Yeah, wow, that one is cut down. That looks like a fun mod. I might have to try that.

As far as balancing goes, drilling small divots where it is heavy, is effective.


And how do you know where it is heavy?

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'81 RD350LC hybrid project bike - in pieces currently
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 Post subject: Re: Flywheel lightening
PostPosted: Fri Aug 10, 2018 2:28 pm 
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Location: Calgary, Alberta
LC Cnd wrote:
I get that balance is key - can this be acheived in a static balance setup, like balancing a motorcycle wheel, or does the flywheel have to be in constant motion to find where to drill to balancing out? Found this photo'd sample on a Harley form. Then there is the question of how much to drill that's the challange. The video, on shaving a flywheel, stated that is not a issue interestingly.


I suspect that turning the OD of a flywheel would not affect the balance. It would simply take off the same amount all around the flywheel.

If anyone has a spare flywheel they'd like to donate, I have all the equipment to do this mod. I even have a tire balancing stand and could make up bushings to mount the flywheel.

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'81 RD350LC hybrid project bike - in pieces currently
'82 RD350LC in '81 colours - Built by "Solo 2" OEM pipes, UNI filters
'90 RZ350F2 with 31K motor, OEM F2 pipes & airbox


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 Post subject: Re: Flywheel lightening
PostPosted: Fri Aug 10, 2018 2:31 pm 
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Joined: Mon Aug 20, 2012 1:37 am
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Location: Calgary, Alberta
RuZty wrote:
Why dick about modifying 30 year old motorcycles? Find and buy a faster motorcycle, for a genuine improvement?
There are plenty available. Not free, but then nothing new ever is.

....unless you enjoy dicking around with old motorcycles, then carry on. :smt002



If someone YAMAHA would simply build this thing then I wouldn't have to dick around with old motorcycles.

Image

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'81 RD350LC hybrid project bike - in pieces currently
'82 RD350LC in '81 colours - Built by "Solo 2" OEM pipes, UNI filters
'90 RZ350F2 with 31K motor, OEM F2 pipes & airbox


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 Post subject: Re: Flywheel lightening
PostPosted: Fri Aug 10, 2018 2:33 pm 
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Location: Calgary, Alberta
RuZty wrote:
A quick calculation puts the difference in inertia of a 2 mm cut to be about -16%, not bad for free. [smilie=cool.gif]


Its not free. It requires ca $10k in machinery and tooling not to mention the years of machining experience to do it correctly. :smt021

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'81 RD350LC hybrid project bike - in pieces currently
'82 RD350LC in '81 colours - Built by "Solo 2" OEM pipes, UNI filters
'90 RZ350F2 with 31K motor, OEM F2 pipes & airbox


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 Post subject: Re: Flywheel lightening
PostPosted: Fri Aug 10, 2018 9:00 pm 
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Free if you already have those things at your disposal. :smt002


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 Post subject: Re: Flywheel lightening
PostPosted: Fri Aug 10, 2018 9:45 pm 
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Location: Calgary, Alberta
Sweat Equity is NEVER free. I've burned myself and cut myself and broken stuff and spent hours upon hours learning how to do this stuff.

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'81 RD350LC hybrid project bike - in pieces currently
'82 RD350LC in '81 colours - Built by "Solo 2" OEM pipes, UNI filters
'90 RZ350F2 with 31K motor, OEM F2 pipes & airbox


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 Post subject: Re: Flywheel lightening
PostPosted: Sat Aug 11, 2018 4:11 am 
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Location: Alberta, Canada
Hooligan wrote:
hondaror wrote:
Yeah, wow, that one is cut down. That looks like a fun mod. I might have to try that.

As far as balancing goes, drilling small divots where it is heavy, is effective.


And how do you know where it is heavy?


There are ways.

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 Post subject: Re: Flywheel lightening
PostPosted: Sun Aug 12, 2018 12:37 am 
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Location: Calgary, Alberta
VERY helpful :smt017

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'81 RD350LC hybrid project bike - in pieces currently
'82 RD350LC in '81 colours - Built by "Solo 2" OEM pipes, UNI filters
'90 RZ350F2 with 31K motor, OEM F2 pipes & airbox


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 Post subject: Re: Flywheel lightening
PostPosted: Sun Aug 12, 2018 2:50 pm 
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Location: Alberta, Canada
Across two scales. Measure, Mark, rotate. You have to calculate, but it works.

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