HUGE magneto breakthrough

APRRSV said:
Jim,
The two 220 uF run better than the JH high capacity condenser?

Ed
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Not much diffirence if any, maybe so but needs more testing. I've got a 330 a 470 and a 680 coming in a couple weeks. I suspect if it gets too high it will be hard to start. I'm looking for less arching so the points don't get dirty.

The important thing is that anyone can order the high capacity .36MFD conderser directly from Hunt and fix a missing problem IF they have one. Its an obviously longer condenser than the standard one.
 
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Just got a very informative call and was recommended to only use capacitors designed for impulse loading to avoid premature failure. 630 volt minimum.
 
jseng1 said:
Just got a very informative call and was recommended to only use capacitors designed for impulse loading to avoid premature failure. 630 volt minimum.
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Hi Jim,
FWIW, I just measured my standard JH condenser and saw 0.282 uF with one of my meters and 0.290 uF on another meter.

The JH website is puzzling in that it states the standard condenser is. 0.36 uF and the upgrade is 0,39 uF.

Ed
 
APRRSV said:
Hi Jim,
FWIW, I just measured my standard JH condenser and saw 0.282 uF with one of my meters and 0.290 uF on another meter.

The JH website is puzzling in that it states the standard condenser is. 0.36 uF and the upgrade is 0,39 uF.

Ed
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Generally, there's a 20% plus or minus tolerance on condensers/capacitors unless otherwise marked. Also generally, for max RPMs you want a higher capacitance which may account for the "upgrade" being .39uf (probably .31uf to .47uf).

Are the condensers you all are trying/testing marked?
 
The standard that JH is sending out now is marked .136MFD Their high capacity codenser is longer length and marked .36MFD But even the JH high capacity condenser breaks up a little for me at high RPM but maybe my magnets are stronger than most. I'll be getting higher capacitors in a couple weeks (need to find some designed for "impulse loading").

The morris "R" condenser is not available anymore and they'll sell you a regular instead.
 
Jim just had a look what about trying the Mallory condensor. Would that be worth a try?

This is the condenser that is mounted on the outside of high amperage Mallory magnetos. This condenser is rated at 0.56μF.
 
jseng1 said:
The standard that JH is sending out now is marked .136MFD Their high capacity codenser is longer length and marked .36MFD But even the JH high capacity condenser breaks up a little for me at high RPM but maybe my magnets are stronger than most. I'll be getting higher capacitors in a couple weeks (need to find some designed for "impulse loading").

The morris "R" condenser is not available anymore and they'll sell you a regular instead.
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That's annoying. The Morris R condenser would last a full seasons racing in their 2005 version rare earth magneto. The regular condenser would last only a few races.
 
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marshg246 said:
Generally, there's a 20% plus or minus tolerance on condensers/capacitors unless otherwise marked. Also generally, for max RPMs you want a higher capacitance which may account for the "upgrade" being .39uf (probably .31uf to .47uf).

Are the condensers you all are trying/testing marked?
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My condenser is marked S6-136.

Ed
 
Get a C-meter (capacitance meter) so you can measure your capacitors exactly. I don't think the 136 marking means .136 uF either. These capacitance meters are cheap now and sometimes incorporated in multimeters.
I remember reading something in my youth about optimizing the capacitor value by looking at the metal deposition on the contacts but it was a long time ago.
Russ
 
As I have said I am not having any problems with my JH, getting full RPMs when I open it up but mine is a road going Norton, I have a bit of hi performance work done to my motor but I'm not racing it, my motor will run freely way past 7000 rpms with out any break down or misfire but if I open it up it's usually just through 2nd and 3rd and not there for long (to many cops and cameras on the roads these days), but get me up in the ranges/mountain roads and twisty roads I love to open it up and do short hi revs in the straights before the next set of corners and have some fun with slower bikes/riders.
I can ride all day and the JH always preforms the way it should from just putting around to hi speed runs through the gears and these days going flat out in top gear is never in my mind, but getting up to the ton and over when I get the chance to do so I know the JH won't let me down when I open that throttle up through the gears, it drives direct off the cam so no retard/advance unit, but mine hangs out in the breeze and not set up behind a hot motor and I still think heat plays a part with condensers if behind the motor.
I can crack the throttle open, and it just takes off and with the short Featherbed frame and hot 850 motor pulling wheelies is a breeze and keeping the front wheel up in the air from 2nd to 3rd with the throttle wide open the JH works perfect, but I don't do that much these days lol.
in over 13 years it's been on my Norton I am still running the points that the JH came with, haven't touched the points since I put it on, the point hasn't burned out but I have replaced the condenser, not from breaking down but damage from a slide down the road, I have 2 spare tune up kits in my parts cabinet but so far while it's running great I leave alone and just check everything when doing an oil change/maintenance on the bike as I do pull the front cover off the JH every so often to lube the felt pad for the point cam and to check on the point, if all good I leave it alone.
Whether I been lucky who knows but after running an older JH on my old Triumph and the new JH on the Norton (both hanging off the side), so 23 years+ without any problems at all running Joe Hunt magneto's and getting very long life out of my N7YC plug (just put new ones in after 35k miles on them).
It always fires up on first kick every time even if it hasn't been run for a while, but as I say my Norton isn't a race bike, it's now my hotrod play bike, I have so much fun on my Norton when up in the tight twisties.

Ashley
 
APRRSV said:
My condenser is marked S6-136.

Ed
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That condenser is available at just about all auto parts stores for under $20. It is a
HUGE magneto breakthrough
brand condenser. I haven't been able to find the uf but I haven't looked hard or written to Standard. Pretty sure that's simply a model number.



HUGE magneto breakthrough
 
Using two 220 uF 630 volt capacitors in parallel works the best so far (stacked on top of each other). I was told that two 220s would last longer than one 470 (permanent?). I tried some very tiny digikey 330 & 470uF capacitors and they didn't work AT ALL. The 220s were physically larger.

Here's the ebay link for the 220 uF capacitors. about $11 for ten of them.
https://www.ebay.com/itm/394482642353?var=663033210192

HUGE magneto breakthrough


Stacked up and epoxied as in photo below:
HUGE magneto breakthrough
 
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jseng1 said:
Using two 220 uF 630 volt capacitors in parallel works the best so far (stacked on top of each other). I was told that two 220s would last longer than one 470 (permanent?). I tried some very tiny digikey 330 & 470uF capacitors and they didn't work AT ALL. The 220s were physically larger.

Here's the ebay link for the 220 uF capacitors. about $11 for ten of them.
https://www.ebay.com/itm/394482642353?var=663033210192

HUGE magneto breakthrough


Stacked up and epoxied as in photo below:
HUGE magneto breakthrough
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So they show good results with no arcing across the points and still runs good at high rpm?
 
Brian Riley said:
So they show good results with no arcing across the points and still runs good at high rpm?
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Yes. Runs absolutely clean at high RPM with the two 220 uF capacitors and better than the JH high capacity condenser (just tested it again). There is still a little flash at the points about every 5 seconds AT 5000 RPM and above but not as bad as before. Too low a uF number and it starts to miss. If I go too high it might be hard to start. I could try a single 470 capacitor but two 220s would probably be more reliable. Happy as it is.
 
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Interesting finds. The Fairbanks Morse Type FM (model J1A) off my BSA Single with Joe Hunt internals has a red cap condenser and seems to work well without excessive arcing at the points and we get clean revs on my electric drill. The condenser measures at 0.420uf. This is a single fire counter clockwise mag with a wasted spark hunt rotor/points cam.

My Dads Rickman Triumph and my Track Master BSA Twin both have a single fire ARD mags and they both run this same "red top" condenser. All three of the Mags run the same single exit point coil. I have some older condensers that have this red cap that all roughly measure 0.420uf, my dad claims the single fire hunt/ard required the high output condenser. Hunt sells a condenser at 0.360uf which is considerably lower than the the 0.420uf that we have and is very close to the value of 0.440 that Jim is running with two condensers in parallel.

Another thing if you dig through the old Tractor forums, guys are repairing and rebuilding their original equipment Fairbanks Morse mags and have been using Ceramic capacitors wired in parallel for years.

HUGE magneto breakthrough


HUGE magneto breakthrough


HUGE magneto breakthrough


HUGE magneto breakthrough
 
Magnetos do not usually provide programmable ignition advance curves. An EMS usually controls both ignition advance and mixture, over the entire usable rev range. It is where most performance gains have been made. However Commando engines are air-cooled, so heat build-up can be a problem when best performance is an objective. Methanol fuel keeps engine temperatures lower.
 
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