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

[Denis Zen]

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.

 

[Denis Zen]

Im thinking if he incrementally splines the shaft that the magnet is attatched to one could advance or retard the timing.

 

[Sidewinder Jerry]

Might be easier to build an adaptor that allows you to move the magneto contact points left or right. This would allow you to make much finer adjustments than a spline shaft would.

 

[curtisfox]

Yes! And you can by offset keyways, to change timing.....Curt

 

[Venice Motor Bikes]

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)

 

[Venice Motor Bikes]

Another important thing to know is that the stock 'black box' CDI coil will advance & retard the timing on it's own with engine RPM

 

[Venice Motor Bikes]

Here's a short video I made showing how the stock 'black box' CDI advances the timing as RPM increases...

Someone was arguing with me the other day on a FB forum saying that the CDI's on these bikes don't have any advance, so here's a quick demonstration of... | By VeniceMotorBikes.com | Facebook

Someone was arguing with me the other day on a FB forum saying that the CDI's on these bikes don't have any advance, so here's a quick demonstration of...

fb.watch

 

[Denis Zen]

Yes thank you guys. I really appreciate the input. I think the off set key may be the answer. I am new to this and am still trying to understand all of this. You guys rock.

 

[Denis Zen]

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.

 

[Denis Zen]

I just noticed the electrode inside the sparkplug is not centered in the sparkpug itself. This could be part of my problem. I am going to get a new one and see what difference if any it will make.

 

[Denis Zen]

Would an adjustable cdi possibly be what I am needing?

 

[Venice Motor Bikes]

Post a picture of your engine set up.

Also... what gas/oil mix are you using?

 

[Denis Zen]

Post a picture of your engine set up.

Also... what gas/oil mix are you using?

I am using Husqvarna 2-stroke oil at 40 to 1 sometimes 30 to 1 depending on the weather.

 

[Denis Zen]

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.

 

[Denis Zen]

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!