Joe Hunt magneto

baz · Nov 21, 2022

Fast Eddie said:
Guess he’s got rugby players legs then ?

Pretty much yeah
I spoke to him recently about it and he confirmed he uses fixed advance on his builds

johnm · Nov 21, 2022

Fast Eddie said:
If you go for a Joe Hunt behind the cylinders, the retard lever shown earlier doesn’t fit.
Hence you’d need the AAU, or not worry about it (as Ashley hasn’t for 40 odd years)!

You mean the one in the photo in post 65 doesn't fit ?

I have never seen one for real but can it not be modified to fit ?

Fast Eddie · Nov 21, 2022

johnm said:
You mean the one in the photo in post 65 doesn't fit ?

I have never seen one for real but can it not be modified to fit ?

I am only referring to the lever. And am only going on what I’ve been told by Jim Schmidt as I recently investigated this same idea with him.

ashman · Nov 21, 2022

Fast Eddie said:
If you go for a Joe Hunt behind the cylinders, the retard lever shown earlier doesn’t fit.
Hence you’d need the AAU, or not worry about it (as Ashley hasn’t for 40 odd years)!

Nigel I have only had the JH on my Norton for the last 12 years or more and one for 9 years on my old Triumph so 21 years all up lol.

jseng1 · Nov 21, 2022

NorLuck said:
You don't sell the bit that the Mercury needs to have a Mag behind the timing cover. In fact I'm still not quite sure what part I do need!
This all I need?: https://www.rgmnorton.co.uk/buy/magneto-automatic-advance-retard-assembly_4367.htm

Yes that is all you should need. The auto advance unit with sprocket fits either the Lucas or the Joe Hunt - the Joe Hunt being more reliable and easier starting in my opinion. Assuming you have the intermediate twin sprocket and chain to the rear. Same with all Domnis and Atlas as below. I would get the auto advance unit - not the fixed sprocket type unless you are racing only.

phippsy · Nov 21, 2022

Been following this thread avidly, now waiting for fast Eddie to post-a video of how easy it is to start , Ashman has always sung praises on magnetos and rightly so , my only question is how good are they in the wet ? Coz I am soo tempted , every bike I ever had with a mag was such an easy starter .

ashman · Nov 21, 2022

phippsy said:
Been following this thread avidly, now waiting for fast Eddie to post-a video of how easy it is to start , Ashman has always sung praises on magnetos and rightly so , my only question is how good are they in the wet ? Coz I am soo tempted , every bike I ever had with a mag was such an easy starter .

They have no problem with riding in the wet at all, have been caught out in some good rain falls while out on my Norton and the JH never missed a beat the front cover is sealed pretty good and as long as you have good sealing plug caps same as any motor.
On my old Triumph with the JH I was traveling with my wife from Brisbane to Newcastle a 900km trip and 400km was in the rain, we were starting to get wet and cold by the time we got there but the JH didn't miss a beat, even parked outside in the rain made no difference to the JH still fired up on one kick.

Ashley

ashman · Nov 21, 2022

baz said:
I'm pretty sure the mercury crankcase is the same as a dommie ?
So if you really want a magneto just fit a Lucas one in place of your dizzy
With an AAU or manual advance

A JH is a lot better than the old Lucas mag, a lot more reliable, more simpler and a lot easier to work on and will produce a lot better bigger spark than a Lucas, I am building a Manxman project bike it has a Lucas competition mag but might replace it with a new JH if it's needs replacing it will be with a JH but I be running it without the AAU, no need for it at all.

Fast Eddie · Nov 21, 2022

phippsy said:
Been following this thread avidly, now waiting for fast Eddie to post-a video of how easy it is to start , Ashman has always sung praises on magnetos and rightly so , my only question is how good are they in the wet ? Coz I am soo tempted , every bike I ever had with a mag was such an easy starter .

Mine will be started on rollers mate so probably not very informative for you !

baz · Nov 21, 2022

ashman said:
A JH is a lot better than the old Lucas mag, a lot more reliable, more simpler and a lot easier to work on and will produce a lot better bigger spark than a Lucas, I am building a Manxman project bike it has a Lucas competition mag but might replace it with a new JH if it's needs replacing it will be with a JH but I be running it without the AAU, no need for it at all.

Old Lucas mags almost always need a rewind because the shellac breaks down over time
And a new condenser
One of the best things I did on my A10 was buying a reconditioned Lucas k2f mag with a recon AAU
You get a massive spark out of it
Usually starts first kick

baz · Nov 22, 2022

NorLuck said:
Ok so for the Mercury if I want a magneto as well then I need the thing I sent in the RGM link ONLY?:
https://www.rgmnorton.co.uk/buy/magneto-automatic-advance-retard-assembly_4367.htm <--- buy this and install it, I don't need anything else like pins/circlips/gears bigger chain, etc? And of course the Magneto...

I've never worked on one of these but I suspect you'd also need the extended nut that goes underneath the magneto
It takes the place of the hard to get too nut that holds the mag at the bottom?
But why do you want a magneto? If the distributor is ok leave it alone
Just maintain the points and charging system etc

texasSlick · Nov 22, 2022

NorLuck said:
Ok so for the Mercury if I want a magneto as well then I need the thing I sent in the RGM link ONLY?:
https://www.rgmnorton.co.uk/buy/magneto-automatic-advance-retard-assembly_4367.htm <--- buy this and install it, I don't need anything else like pins/circlips/gears bigger chain, etc? And of course the Magneto...

You. have all you need.. bolt up the magneto on the left, mount the AAU on it's shaft, nip up the drive chain, and time the mag.
You do not need the extended nut ..... you have the upgraded version which is accessible from inside the timing case .....that nut is about 5 o'clock under the leftmost sprocket.

Slick

Fast Eddie · Nov 22, 2022

NorLuck said:
It's just romantic is all... Honestly not practical since the Mercury has the Tri-Spark installed already and all the wiring done and works with my new alternator etc.
Also would need to get that tacho attachment... Oh @Fast Eddie are you getting that Joe hunt mag attachment that lets you get digital revs? Or are you going to go old school with a magnetic style tacho cable?

I wanted one of those tacho readers that plug into the tacho drive and translate it into a digital signal but I don't know which one to buy that would work on the commando. Anyone done this?

I’ll be using a Scitsu tacho, it takes the readings from the HT leads.

Fast Eddie · Nov 22, 2022

NorLuck said:
Ahhh the M-unit will allow readings from the negative wire on the coils w/fuse but to run straight from HT leads I need a special device and in that case I might as well get the JH one since it's a bit cleaner of an install.

I have seen ones that run off the tacho drive but I guess that's one more mechanical thing you have to lube/etc.

Can’t really comment, you’re running much more high tech stuff than me.

I’m in the keep it simple camp… with the luddites !

t ingermanson · Nov 24, 2022

Only issue I've had with the Hunt mags is a couple times a lead fell off while riding, so I made some washers for safety wiring them on. Not too tight, but something more than what the cap offers. Not a problem since.

jseng1 · Nov 24, 2022

t ingermanson
There are better leads that you have to force into the cap - they snap in and don't come loose.

The photo below shows why some people prefer a magneto over a distributor or EI - you can get rid of the battery and clean up the looks - especially effective on a stripped down cafe bike.

seattle##gs · Nov 24, 2022

I have a friend who has a JH mag on his mix-n-match, the reoccurring problem is the leads tend to fall out. JH recommends using the 8mm wires and that has helped. You did an excellent job of safety wiring.

ashman · Nov 24, 2022

If you use angled plug caps they sit better in the cover, I have had a cap pop out while riding but was an easy fix by installing a bridge down low between the plug leads this has stopped the leads from dropping out.

Fast Eddie · Nov 24, 2022

t ingermanson said:
Only issue I've had with the Hunt mags is a couple times a lead fell off while riding, so I made some washers for safety wiring them on. Not too tight, but something more than what the cap offers. Not a problem since.
View attachment 101524

Nice wiring there sir.

You might wanna tighten up your float bowl sump plug though…

ashman · Nov 24, 2022

I don't run my light during the day but I do run a very small 12 volt battery for a nice bright brake light as well if I do need to run my head light in the dark, I was originally running all my power off the ALT with a battery eliminator worked OK if you like a dull head light as well it dies when you hit the brake, running a small dirt bike battery has fixed that and have it mounted in the under seat tool tray, will take a pic of that as well.

Joe Hunt magneto

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