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#211 Re: The Audio-Talk Motorcycling thread.

Posted: Tue Jun 12, 2018 10:16 pm
by Dave the bass
I've done a lot of learning recently. Ignition timing, its quite important isn't it :)

The Advance/Retard unit on the mighty Bullet appears to have seized in a middle position, somewhere between the 10 degree and 32 degrees it should be at full advance or retard.
This is the unit...
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The grease on the points cam has gone solid and cam no longer responds to the influence of those little bobweights, additionally, the little return springs have been stretched and have lost their 'boingboingyness'. Took me a while to work out whats going on and how it should work.

I've found end float on the distributor pinion too which has cause the AR unit to physically contact the back of the CB plate. Meh...
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Livin' n learnin'.

#212 Re: The Audio-Talk Motorcycling thread.

Posted: Tue Jun 12, 2018 10:40 pm
by IslandPink
So, after all of this learning, do you feel you're advanced or retarded ?

#213 Re: The Audio-Talk Motorcycling thread.

Posted: Wed Jun 13, 2018 8:16 am
by Dave the bass
Advanced fo' sho, it's the only way forward.

#214 Re: The Audio-Talk Motorcycling thread.

Posted: Thu Jun 14, 2018 8:20 pm
by Mike H
Dave the bass wrote: Tue Jun 12, 2018 10:16 pm I've done a lot of learning recently. Ignition timing, its quite important isn't it :)
Just a bit! :D

#215 Re: The Audio-Talk Motorcycling thread.

Posted: Sun Jun 17, 2018 11:26 am
by pre65
For our DTB.

Have you seen the AMAL tuning guide ?

http://amalcarb.co.uk/downloadfiles/ama ... _guide.pdf

#216 Re: The Audio-Talk Motorcycling thread.

Posted: Sun Jun 17, 2018 11:49 am
by Mike H
Line of unrelated context demarcation.
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Friday June 8 - (23 minutes)




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#217 Re: The Audio-Talk Motorcycling thread.

Posted: Sun Jun 17, 2018 8:52 pm
by Dave the bass
Those place names....you're touring Middle Earth Mike?!

Over in the A-T Cycling thread our Pops asks....
pre65 wrote: Sun Jun 17, 2018 10:23 am
Do you have a specific problem with the Enfield ?
Yes, for starters just the mere fact its an Indian Enfield from the early 90's :)

I've owned it for 20 years and when I 1st had it found it would do an odd missfire when it got up to working temperature on occasions, on some of these 'occasions' the carb sometimes got blown totally off its rubber mounting manifold! Great fun I can tell you!

One of the previous owners who'd 'done battle' with it had fitted Boyer Electronic Ignition. Its a Mk3 version that I've read was apparently sensitive to poor battery voltage regulation and would play havoc with the ignition timing curve. I didn't know this at the time and thought it was a carburation fault so I purchased a Mk1 Amal Concentric in late 1999 and fitted it expecting it to solve all the problems, it didn't. So I retired the Bullet shortly after and used it as a workbench for the next 18 years to make various size loud speakers and stuff on....

Fast forwards 18 1/2 years...

The mechanical ignition timing mechanism seized last week causing similar problems to 20 years ago. Aaaarrrggghhh! Only now I know why its doing it and have rectified the problem now. Since having nailed the Ignition timing fault I've been trying to implement the Amal Mk1. I had to open the inlet port out to 30mm to get it to match up with the Carb, 900 series 30mm job. I did that successfully....
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...and in addition to a very free flowing exhaust system and miminal air filtering have found the jetting is now on the lean-side because the carb was supplied set up specc'd with the restrictive convoluted Indian Air filter system and very heavily baffled exhaust system. Thats all gone now so I've had to learn how to plug chop, read, re jet and fettle the carb to avoid glitches in the throttle response.

A mate who races a pair of Yamaha SR500's has supplied a pair of throttle slides with a different cutaway to better match my current air filter and exhaust combo for testing purposes.
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Brum brum! Getting there...
https://www.dropbox.com/s/fhplqshroz9v6 ... 6.mp4?dl=0

#218 Re: The Audio-Talk Motorcycling thread.

Posted: Sun Jun 17, 2018 9:11 pm
by pre65
Well done Dave, you seem to be on top of the situation. :)

#219 Re: The Audio-Talk Motorcycling thread.

Posted: Sun Jun 17, 2018 9:22 pm
by Dave the bass
Thanks Popz, yeah getting there.

#220 Re: The Audio-Talk Motorcycling thread.

Posted: Mon Jun 18, 2018 9:46 am
by Mike H
Image All very good. Watching .. Image



Line of unrelated context demarcation.
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Tuesday June 5th:

Devizes to Rhosgoch(YouTube, timelapse, 13 minutes)




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#221 Re: The Audio-Talk Motorcycling thread.

Posted: Mon Jun 18, 2018 11:17 am
by andrew Ivimey
Slightly bizarre, kind of uncomfortable....the music counterpoints the surrealism of the underlying metaphor.... I quite liked it!

#222 Re: The Audio-Talk Motorcycling thread.

Posted: Mon Jun 18, 2018 12:50 pm
by Greg
Dave, I think that’s an Amal Mk2 concentric you are showing there. The Mk1 had the float chamber mounted to the side of the carb body. If you think a Mk2 is fiddly to tune, you should try a Mk1. Nightmare!

#223 Re: The Audio-Talk Motorcycling thread.

Posted: Mon Jun 18, 2018 1:07 pm
by pre65
Dave's carb is an Amal concentric.(Mk 1)

The Concentric Mk 2 is very different.

The Amal with the side mounted chamber was the Monoblock. :)

#224 Re: The Audio-Talk Motorcycling thread.

Posted: Mon Jun 18, 2018 1:30 pm
by Mike H
andrew Ivimey wrote: Mon Jun 18, 2018 11:17 am Slightly bizarre, kind of uncomfortable....the music counterpoints the surrealism of the underlying metaphor.... I quite liked it!
Oh yes, all of that! :lol:

I don't just throw this stuff together you know

:D

#225 Re: The Audio-Talk Motorcycling thread.

Posted: Mon Jun 18, 2018 5:01 pm
by Greg
pre65 wrote: Mon Jun 18, 2018 1:07 pm Dave's carb is an Amal concentric.(Mk 1)

The Concentric Mk 2 is very different.

The Amal with the side mounted chamber was the Monoblock. :)
Ah, ok. My memory is a bit rusty. Must be about 40 years since I played with these things.