Joe hunt magneto

Soulkitchen · Jan 31, 2013

Not sure I can afford the 765.00 though. And not sure i will ever find a used one.

Dkt26 · Jan 31, 2013

There is one on eBay for bout $350 at the moment. Older one tho

jseng1 · Feb 1, 2013

Dkt26 said:
Sorry but I'm learning,
does the hotter spark negate the need for the advancing spark at higher rpm on the commando side mount unit? Is the advance mechanism within the timing chest of the atlas style mounted Maggie just there because its there or does it perform a function of some measurable benefit that the side mounted version does not?
I love the idea and look but I have had so many ignition problems, I'm over it. Points- pain in the arse. 3 trispark units that have all blown up due to manufacturer issues ( replaced under warranty) and now Boyer that has worked ok, but I have no faith in.

The hotter spark just makes for better ignition of the fuel. It has nothing to do with the timing. Full advance is always going to be the same - preferably at 28 degrees. The Auto advance unit lets you start the bike with the ignition retarded and that reduces the chance of kick back at the kick lever. It may also reduce chance of pinging when letting out the clutch at low RPM.

But you don't hear many complaints. The advantages remain.

check out videos

starting with magneto demo
http://youtu.be/3D4VIzMNNYM

machinist going the extra reinforcing mile (or you can reinforce with JB weld according to the instructions if you really thing its necessary - Evil Kenievel jumps etc).
http://youtu.be/ZVE1ZzlsXhM

concours · Feb 1, 2013

jseng1 said:
Dkt26 said:

Sorry but I'm learning,
does the hotter spark negate the need for the advancing spark at higher rpm on the commando side mount unit? Is the advance mechanism within the timing chest of the atlas style mounted Maggie just there because its there or does it perform a function of some measurable benefit that the side mounted version does not?
I love the idea and look but I have had so many ignition problems, I'm over it. Points- pain in the arse. 3 trispark units that have all blown up due to manufacturer issues ( replaced under warranty) and now Boyer that has worked ok, but I have no faith in.

Click to expand...

The hotter spark just makes for better ignition of the fuel. It has nothing to do with the timing. Full advance is always going to be the same - preferably at 28 degrees. The Auto advance unit lets you start the bike with the ignition retarded and that reduces the chance of kick back at the kick lever. It may also reduce chance of pinging when letting out the clutch at low RPM.

But you don't hear many complaints. The advantages remain.

check out videos

starting with magneto demo
http://youtu.be/3D4VIzMNNYM

machinist going the extra reinforcing mile (or you can reinforce with JB weld according to the instructions if you really thing its necessary - Evil Kenievel jumps etc).
http://youtu.be/ZVE1ZzlsXhM

Let me get this straight, you run a Joe Hunt mag on your Commando, on the end of the cam, with no automatic advance? And, you set up your static timing at 28 degrees BTDC?

lcrken · Feb 1, 2013

concours said:
Let me get this straight, you run a Joe Hunt mag on your Commando, on the end of the cam, with no automatic advance? And, you set up your static timing at 28 degrees BTDC?

I've run both Joe Hunt and ARD mags on my Commando racers, and that's exactly how I time them. I set them up at 28 degrees before TDC static, and then check with a timing light to make sure that's where the timing is when the engine is running. Back when I ran them with points and coil ignition, I also set them up for 28 degrees timing at full advance. I've run Commandos on the street with the same fixed timing, and it seemed to work ok, but I prefer to have some advance mechanism to make starting easier, particularly with high CR.

Ken

Dkt26 · Feb 1, 2013

Thanks guys for the info regarding advance etc.
that reinforcing plate is an awesome little piece of kit. Not sure why you would need it unless you were planing to lay it over on that side but regardless, very nice addition.

ashman · Feb 1, 2013

You no need to advance the Joe Hunts to start your Norton, once set up at the right timming it will start frist kick every time, be carefull about buying a second hand Joe Hunt as they probly be for a Triumph, they run the other way to a Norton and won't work unless you get them remagginized to run the other way.

Ashley

Dkt26 · Feb 1, 2013

After all my ignition issues, I'd only buy a new one ash. Lessons learned long ago my friend.

ashman · Feb 1, 2013

I brought a second hand one for my Triumph, but that was from a friend who had it rebuilt before I brought it, it was on the Triumph for 9 years and 250,000 ks and I never had any problems with it at all, but paying $765 for a new one that will outlast any thing else is a small price I recond.

Ashley

jseng1 · Feb 2, 2013

Think of it this way.

Norton's start very easy with the new style magnetos that have rare earth magnets - probably easier than with any other ignition. They usually start before the kickstarter reaches bottom. It kind of surprises you when there is no resistance in the bottom 1/2 of your kick. This doesn't happen with electronic ignitions because you usually need a full turn of the motor before the ignition is activated and begins to spark. This is the problem with Boyers.

When they start this easy an advance system doesn't seem to be necessary (better worded as a retard system at 0 RPM). The Atlas style auto advance for magneto goes to full advance at 2500 RPM and that range isn't good for anything but putt-putt-ing and idling anyway - so who cares.

If you do care - Check out this Morris mag retard kit - i don't know if it fits a Joe Hunt or not. It might, looks very similar.

http://www.morrismagneto.com/mra.htm

worntorn · Feb 2, 2013

I often wonder what the advance curve looks like with the Boyer. It feels as though the engine goes to full advance as soon as rpm picks up from idle.
On the other hand, I have Boyer on two Nortons, it has worked well and starting is very easy, one or two kicks cold, always one kick when warm.
I'll pay attention to whether it starts in the first half of the kick or the second, but I seem to recall it is just as you say, the engine fires at the bottom end of the kick or even after if there is still rotation.

Glen

concours · Feb 2, 2013

Based on automotive experiences, I'd have thought that 28 degrees of advance at cranking speeds would cause the crankshaft to want to turn backwards when the fire was lit that early. :shock:

Matt Spencer · Feb 3, 2013

Another solution to the great mounting delima ;

jseng1 · Feb 4, 2013

Here's the answer to the advance for Commando magneto.

You flip the lever to retard the ignition 20 degrees for starting. Looks like it fits right onto the Joe Hunt mag. I haven't tested it yet but I'm looking into it.

I think you want the MRA-G with a black cap - available from Morris at:
http://www.shop.morrismagneto.com/produ ... tegoryId=3

Should fit right onto the Joe Hunt below. Note the upgrade allen screws I provide - much nicer because they don't fall off the srewdriver.

snail · Aug 31, 2015

Recycling an old thread but...
My basket case 850 came with a Joe Hunt hanging off the right hand side.
Trouble is, I think I have the wrong rotation version . With the cover off and the coil at the top, the points are at bottom right, condenser on the left. When spun anticlockwise I get a mediocre spark. When spun clockwise the spark is great!
3 questions :
1) What's involved in converting what I have?.
2) Should I buy a Triumph so that the rotation is correct....
3) Is it possible to upgrade to the rare earth magnets ? (this is a 70's mag)

I'd prefer not to mount it behind the cylinders as I'm trying to keep this old (drag) bike as original as possible.
I can't seem to get the Joe Hunt people to answer my emails.

cheers,

Brian

johntickle · Aug 31, 2015

When you spin the rotor clockwise on the drive side it turns anti clockwise on the points side. I think you only need the "anti clockwise" mounting plate for the points and a set of "anti clockwise" points.

snail · Aug 31, 2015

Thanks John,
I wasn't sure if I'd need to alter the relative positions of the magnets and (points) cam to make the pulse at the same time as the points open. I don't have much experience with maggies so need all the help I can get!

Brian

ashman · Aug 31, 2015

johntickle said:
When you spin the rotor clockwise on the drive side it turns anti clockwise on the points side. I think you only need the "anti clockwise" mounting plate for the points and a set of "anti clockwise" points.

I am not sure its that simple, I think the magents need to be remaginzed to run the other way, Joe Hunt will do that cost about $100, when I frist brought my mates old J/H I tryed to run it on my Norton with changing the points to run anti clockwise but didn't work so it ended up on my Triumph at the time.

Well my J/H has been on my Norton for 6 years now and 30,000 miles, it still starts first kick everytime without fail, I take the cover off every so often to put a few drops of oil on the felt for the point cam, so far I haven't touched the points in the 6 years, the points if need cleaning just use a peice of rage with a bit of mefo or white spirt on it, do not use a points file on them as that will take the harding off them and they will fail in a few months.

Ashley

dynodave · Aug 31, 2015

worntorn said:
I often wonder what the advance curve looks like with the Boyer. It feels as though the engine goes to full advance as soon as rpm picks up from idle.

"the boyer".......which boyer??????????????????
TOP SECRET don't look here:
http://atlanticgreen.com/boyerexposed.htm
http://atlanticgreen.com/boyerevolved.htm

concours said:
Based on automotive experiences, I'd have thought that 28 degrees of advance at cranking speeds would cause the crankshaft to want to turn backwards when the fire was lit that early. :shock:

Bob that's where the 21 lb flywheel comes in handy...inertia
You might get quite different results with higher compression, low overlap cam and a light flywheel... remember a stock commando is hotter relatively speaking than a 325HP 327corvette

74ok · Aug 31, 2015

the fact that top fuel dragsters run twin mags speaks volumes
https://www.google.ca/search?q=top+fuel ... ster+night

http://www.msdperformance.com/msdpromag/

The Pro-Mag 44® is the King of all magnetos! Producing an amazing 44 amps of primary current, it’s no wonder that the Pro-Mag 44 is the choice of top fuel dragster and funny car teams!

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bwolfie said:
If you look at the evolution of the aviation industry, Mag Ignition was the standard for the bulk of time. But in recent years there has been a switch to a redundant EI system. So I would say a Mag is cool and does work well. But a good EI system will also work well. Nowadays it comes down to preference. With a mag there are more parts to wear out, but with an EI there are lots of little electronic parts to fail. 6 of one half a dozen of another. Also to add to this, the aircraft EI systems also get used with EFI. Again removing another old technology.

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RoadScholar said:
My son is an aircraft mechanic, he works for a .org in the east that has a B24, B17, Mustang, and many other vintage planes, all with magnetos; he swears by their reliability and their performance. He and I agrue about the virtues of all solid state (my position) versus these electro-mechanical wonders. So , I claim that the solid state produces a more consistent, repatable spark, has less moving parts and puts out a hotter spark which doesn't trail off with RPM, he claims that a mag puts out an ever increasing spark with RPM, but acknowledges that the engines he works on rarely exceed 3000 RPM.

So does a mag do a better job of igniting the mixture than, say, a TriSpark with a 5 ohm dual fire Dyna coil, supplied with the juice from a Sprax high out put charging system??

Or

Is the mag just a period piece that allows the standard charging system to light the way at night or is it a real, respectible, performance piece that out shines electronics????

Wondering.

Bill.

Joe hunt magneto

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