Should I ask my friend who owns a machine shop to build this?

Denis Zen

Active Member
Mar 30, 2021
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Riding up highway 101 at sunset
I have a friend who owns a machine shop, should I ask him to build a splined shaft that will allow for us to reposition the magnet on the magneto to advance or retard the timing or has this been resolved and if so where do I find such a thing?

He develops parts for Boeing and has the resources to do this... If i can get him interested.

PLEASE LEAVE YOUR THOUGHTS AND SUGGESTIONS HERE.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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Los Angeles, CA.
Jim (Manic Mechanic) used to make a wedge collar that would allow you to adjust the timing of the magnet by rotating it & locking it down.
The problem with it was that you also need a degree wheel to see exactly where the timing is set to. (31* BTDC is best for most air cooled engines).

If you give it too much advance, the engine will feel like it has more power but will run too hot & quickly burn up. :(



Here's the thread... Adjustable ignition timing | Motorized Bicycle Engine Kit Forum (motorbicycling.com)
 
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Denis Zen

Active Member
Mar 30, 2021
118
141
43
Riding up highway 101 at sunset
Has anyone tried the offset key and if so where do i find them and is the offset to the left or right?

See my problem is it starts bogging from 35 mph or the last 1/8 of my throttle.

I can get to 40 mph but its not running smoothly but surprisingly my sparkplug stay very clean and only has detonation scorch on one small spot at the front of the electrode. See photo.

Should I be happy with what I have and leave well enough alone or maybe go with the offset key to get full power band.

It only bogs on flat road but runs right when going up a slight incline.
 
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Denis Zen

Active Member
Mar 30, 2021
118
141
43
Riding up highway 101 at sunset
Its a hardrock with a heavy duty double wall front rim with 16 in front mira ceramic disc brake .. . Anbull 80 cc no mods. Niome flex exaust pipe, generic "high performance" carb.

A case mounted spring arm and stock tensioner with a tensioner from a clothes dryer motor mounted over the top loop of the chain to help keep back lash in the chain down With an after market shim that goes above the front sprocket to mitigate chain jam. I run problem free.

I have a 6 volt add on magneto powering my 12 volt cree head lamp. Yeah it flickers but when I rev high it wont blow my lamp out and at 10 mph its fully lit .
It anit no work of art like yours but im happy with my first build.

The next one will be the one I will be making trick.
 

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Denis Zen

Active Member
Mar 30, 2021
118
141
43
Riding up highway 101 at sunset
Well I bought a handful of sparkplugs and have been playing with gap size and Ive got it to purr t.w.o. ( throttle wide open) all the way up to 39 mph... The last little bit still sputters but I can get it to purr if I feather it a little. 40 mph is all I can get it to go.

Plugs are clean, no smoke, fires strong. I am going to try re jeting it smaller. I found a re jet kit that has every size from 45 to 75 in 2 mm increments $12.00 on amazon
just too see what it does.

Thanks everyone who replied!!! Love y'all!

Yer great!