BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike Sponsor SteadfastCyclesBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorHepolite PistonsBritBike Sponsor
Upgrade to: Gold Membership | Premium Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
JubeePrince
JubeePrince
Back on the mainland!
Posts: 7,660
Joined: November 2005
ShoutChat Box
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
a word from..
Manuals on DVD (Shipping included)
Previous Thread
Next Thread
Print Thread
Rate Thread
Condenser Grounding?
#810053 05/24/20 12:15 am
Joined: Jun 2016
Posts: 136
mrcarb Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Jun 2016
Posts: 136
I am installing the condensers into a new, which is also painted, coil platform on a 76 Bonneville. The condensers are bolt-in and my question is should the paint be sanded off the coil platform where the condensers bolt in for grounding purposes?

Thank you in advance

Support Your #1 BritBike Forum!

Check out British motorcycles for sale: British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Re: Condenser Grounding?
mrcarb #810057 05/24/20 12:38 am
Joined: Nov 2008
Posts: 3,097
Likes: 6
Britbike forum member
Online Happy
Britbike forum member
Joined: Nov 2008
Posts: 3,097
Likes: 6
Don't know about condensers, haven't run any in over 30 years, but read this;

http://gabma.us/wp-content/uploads/2015/09/proper_grounding.pdf


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: Condenser Grounding?
mrcarb #810059 05/24/20 12:42 am
Joined: Sep 2013
Posts: 2,464
Likes: 15
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2013
Posts: 2,464
Likes: 15
yes the condensers must be individually grounded or they are not in circuit .

if you dont want to sand this particular spot... use a jumper wire to the hold down bolt ..back to ...or near the battery... where
" grounds" are gathered .
( the harness already has red harness wire in the coil tray area ) ... jumper a wire from the zener or rectifier red to
each capacitor bolt and then you can leave the powder coat more pristine .

there may be some conductivity through the bolt threads ... but cleanly made red jumper wires will make these redundant .

Last edited by quinten; 05/24/20 1:15 am.
Re: Condenser Grounding?
mrcarb #810083 05/24/20 8:03 am
Joined: Sep 2011
Posts: 1,059
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2011
Posts: 1,059
Likes: 1
Was nearly 40 years ago I painted my 650 frame. The condensers were mounted either side of a frame plate, sharing the same screw but insulated by paint. The engine would run but not over ..oh... about 5% throttle. I rode around for some time like this, had me baffled till I cleaned back the paint and allowed the condensers to contact ground, then boom... full power!
So yes, condensers need a proper ground.

Re: Condenser Grounding?
mrcarb #810092 05/24/20 12:06 pm
Joined: Oct 2012
Posts: 4,947
Likes: 7
Britbike forum member
Online Content
Britbike forum member
Joined: Oct 2012
Posts: 4,947
Likes: 7
The condensers can be mounted with a common screw as mentioned and ideally should have a grounded wire from the mounting screw to the engine.


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Re: Condenser Grounding?
Hillbilly bike #810104 05/24/20 1:25 pm
Joined: Mar 2006
Posts: 4,375
Likes: 7
Britbike forum member
Online Content
Britbike forum member
Joined: Mar 2006
Posts: 4,375
Likes: 7
Originally Posted by Hillbilly bike
The condensers can be mounted with a common screw as mentioned and ideally should have a grounded wire from the mounting screw to the engine.

The standard T140 condensers have a stud and nut fastening to the (coil) plate, also a mica insulating washer to prevent the condenser body touching the mounting plate which can be lost or thrown away with the old condenser. If the standard rectifier is fitted then the condensers have a ground connection through the rectifier red positive wire to the harness/battery(+) as the rectifier is attached to the same plate.
[Linked Image from baxtercycle.com]


Edit: Early T140s had different condensers with a bolt fitting.

Last edited by L.A.B.; 05/24/20 6:18 pm. Reason: Additional information
Re: Condenser Grounding?
mrcarb #810131 05/24/20 5:14 pm
Joined: Jun 2016
Posts: 136
mrcarb Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Jun 2016
Posts: 136
The coil platform plate that I received is either painted or powder-coated so it looks like i will need to remove the coating where the condensers and the rectifier mount for a proper ground. I will also remove the coating where it bolts to the bike for a good ground.

This bike has the condensers pictured above and does not have the Mica washers that L.A.B. described so i will check a parts list for those mica washers. I hope that all this will help.


Thank you for all your replies!

Re: Condenser Grounding?
mrcarb #810133 05/24/20 5:27 pm
Joined: Nov 2008
Posts: 3,097
Likes: 6
Britbike forum member
Online Happy
Britbike forum member
Joined: Nov 2008
Posts: 3,097
Likes: 6
Or run a wire from the condensers back to the battery. Removing the paint will cause the metal to rust and rust is not a good conductor.


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: Condenser Grounding?
mrcarb #810139 05/24/20 5:58 pm
Joined: Jun 2016
Posts: 136
mrcarb Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Jun 2016
Posts: 136
Thanks desco. Does the insulating washer go between the condenser and the coil platform plate? Also, where can the insulating washer be purchased?

Re: Condenser Grounding?
mrcarb #810140 05/24/20 6:06 pm
Joined: Nov 2008
Posts: 3,097
Likes: 6
Britbike forum member
Online Happy
Britbike forum member
Joined: Nov 2008
Posts: 3,097
Likes: 6
Again, don't know anything about condensers. Discovered EI over 30 years ago and have not had to mess with condensers, points or timing since. I would suggest you do the same.


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: Condenser Grounding?
mrcarb #810142 05/24/20 6:12 pm
Joined: May 2013
Posts: 6,665
Likes: 18
Britbike forum member
Offline
Britbike forum member
Joined: May 2013
Posts: 6,665
Likes: 18
Nothing wrong with a decent set of points providing you have the patience to adjust them.

However unless your going to have the bracket plated, rust isn’t your friend, be just as easy to fit a length of wire with some ring terminals and attach one end to the condenser mounting bolt and the other to a reliable ground.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (undergoing restoration)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Re: Condenser Grounding?
mrcarb #810143 05/24/20 6:13 pm
Joined: Mar 2006
Posts: 4,375
Likes: 7
Britbike forum member
Online Content
Britbike forum member
Joined: Mar 2006
Posts: 4,375
Likes: 7
Originally Posted by mrcarb
This bike has the condensers pictured above and does not have the Mica washers that L.A.B. described so i will check a parts list for those mica washers.

I'm not sure if they were available separately. Only supplied with the condenser.

https://www.baxtercycle.com/product/19-1847-Lucas/
[Linked Image from baxtercycle.com]

Edit:

Originally Posted by mrcarb
Does the insulating washer go between the condenser and the coil platform plate?

The insulating washer prevents the condenser case(-) from potentially shorting to the plate(+) but of course, the condenser stud(+) should not be insulated from the plate.

Last edited by L.A.B.; 05/24/20 6:24 pm.
Re: Condenser Grounding?
mrcarb #810145 05/24/20 6:28 pm
Joined: Nov 2012
Posts: 1,414
Likes: 5
Britbike forum member
Offline
Britbike forum member
Joined: Nov 2012
Posts: 1,414
Likes: 5
Don't waste your time, or paintwork. That's at best a half-arsed solution.

Do as Deso described, make a proper ground link to the +ve side of the system.
He's already linked the GABMA SPG advice. Even if you don't fully implement that, at least connect the mountings of the condensers to the rectifier ground (the rectifier should already have a ground red wire connection.

Don't rely on efficient grounding via metal parts, it is vulnerable to corrosion.

I don't know what those mica washers are for, I can only imagine that the condenser body is live, so the end of it is close to the plate to which it is bolted, so perhaps vibration could bring it into electrical contact? Or perhaps a moisture short?
That it is mica suggests that its handling high voltage, which I suppose it is with the hundreds of volts back emf from the coil when the points open.
I'd just not heard of a mica washer being needed for a condenser before.

Best of.

Re: Condenser Grounding?
koan58 #810150 05/24/20 7:18 pm
Joined: Jun 2007
Posts: 6,831
Likes: 6
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2007
Posts: 6,831
Likes: 6
Originally Posted by koan58
Don't rely on efficient grounding via metal parts, it is vulnerable to corrosion.


Best of.

I don't understand this statement. Every connection on your motorcycle aside from the soldered one are mechanical interface connections and even solder could be considered a mechanical interface.

You must mean unprotected connections such as bare steel. In which case use grease or paint to protect the connection.

Also, don't get confused by the term "single point ground". You might imagine 20 wires connected to the positive side of your battery. Usually there is only one or two wires going to the battery ground, then a point on the frame where the grounds are distributed. And I disagree with the idea that the frame is not a good bus bar for ground distribution. This is common practice in electronics. Unprotected bolted connections or expecting the head stock bearings to be proper grounds is the usual mistake that folks make. The next are broken bullet female connectors. Those can be a bugger to find.

I make liberal use of dielectric grease to protect electro-mechanical connections. Especially helpful in handlebar switches which have a brutal life.

Poorly grounded condensers will make your life miserable as I recently found out with my old 6T. The internal ground in my distributor had managed to gain some resistance causing hard starting and occasional miss. I corrected this by tightening the two screws that hold the Bakelite points platform to the distributor body and restoring the mechanical interface ground connection.

Cheers,
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Condenser Grounding?
mrcarb #810155 05/24/20 8:03 pm
Joined: Nov 2012
Posts: 1,414
Likes: 5
Britbike forum member
Offline
Britbike forum member
Joined: Nov 2012
Posts: 1,414
Likes: 5
[Don't rely on efficient grounding via metal parts, it is vulnerable to corrosion.]

HT Bill "I don't understand this statement. Every connection on your motorcycle aside from the soldered one are mechanical interface connections and even solder could be considered a mechanical interface. You must mean unprotected connections such as bare steel. In which case use grease or paint to protect the connection."

Bill, I would have thought that it would be easily understood and accepted by now that expecting electricity to find its way back from a component to ground (say battery +ve and/or rectifier +ve, in a +ve ground system) it should not have to pass through dodgy electrical connections (eg painted/corroded surfaces or greasy steering head bearings).

I would have thought it would be obvious that was what I meant by "metal parts". Of course I know that wires, terminals and solder are also made of metal.

Cheers.

Re: Condenser Grounding?
mrcarb #810239 05/25/20 4:23 pm
Joined: Oct 2012
Posts: 4,947
Likes: 7
Britbike forum member
Online Content
Britbike forum member
Joined: Oct 2012
Posts: 4,947
Likes: 7
The points are grounded directly to the engine.The condensers should also be grounded directly to the engine and as close to the points as practical for best performance. And the grounding wire from the engine directly to the grounded battery terminal.


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..

Moderated by  John Healy 

Link Copied to Clipboard
Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Gold Membership | Premium Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.7.4