Author Topic: Advance retard springs  (Read 408 times)

Offline Rudgeman

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Re: Advance retard springs
« Reply #15 on: 04.09. 2019 11:43 »
Thanks for all the contributions. I'm quite pleased that my calcs agree very closely with the chart provided by Julian. It confirms the Draganfly spring is right and my pinking problem was down to the wrong springs being fitted by a previous owner.

It reinforces for me the importance of finding a reliable supplier - there's so much junk out there, and it's hard to spot the problems until it's too late.

R

Offline cyclobutch

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Re: Advance retard springs
« Reply #16 on: 04.09. 2019 11:51 »
It almost seems as if the system was designed to be correct at around 2,500 to 3,000 (the sort of revs most would cruise at) and them simply retard it for starting, without any consideration regarding how advance affects economy, power and general running throughout the rev range.
I reckon you've got that right.

And which pretty much emulates doing this with a manual advance set up.
Various, including ...
'58 Iron Head Flash Bitza


Online Greybeard

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Re: Advance retard springs
« Reply #17 on: 04.09. 2019 11:54 »
It almost seems as if the system was designed to be correct at around 2,500 to 3,000 (the sort of revs most would cruise at) and them simply retard it for starting, without any consideration regarding how advance affects economy, power and general running throughout the rev range.
I reckon you've got that right.

And which pretty much emulates doing this with a manual advance set up.

I was going to say that but as I've never used a manual A&R on a motorbike, I kept my trap shut. On my 1929 Austin Seven there was manual control, I did change it to suit driving conditions. The other lever is a manual throttle control.

Online RichardL

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Re: Advance retard springs
« Reply #18 on: 05.09. 2019 01:43 »
Give me F=KX or give me death!

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Online muskrat

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Re: Advance retard springs
« Reply #19 on: 05.09. 2019 09:26 »
Good one Richard. I had to look it up.
https://en.wikipedia.org/wiki/Hooke%27s_law  *dunno*
Cheers
'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
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Online groily

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Re: Advance retard springs
« Reply #20 on: 05.09. 2019 09:55 »
Me too!
First thought was it might be some new moderation-avoiding form of foxtrot oscar-ing, but should hav known you'd be above all that Richard!
Bill

Online duTch

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Re: Advance retard springs
« Reply #21 on: 05.09. 2019 10:15 »

 yeah and I thought it wuz some kind of death-metal reference  *conf2*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline Joolstacho

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Re: Advance retard springs
« Reply #22 on: 06.09. 2019 00:00 »
As expected... more of an on-off switch than a curve.

Online RichardL

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Re: Advance retard springs
« Reply #23 on: 06.09. 2019 02:28 »
I suppose it's understandable that none of my good friends on here from the British Empire picked up the Patrick Henry reference, something we over here all  learned in grade school back when the Amercan Revolution was not as far in the distant past. Trust me, I was not making a political reference.

https://en.m.wikipedia.org/wiki/Patrick_Henry

Richard L.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.