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
Hugh Jorgen
Hugh Jorgen
Florida
Posts: 419
Joined: March 2019
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
Reducing oil leak into magneto
#772130 04/28/19 1:27 am
Joined: Aug 2016
Posts: 73
BevanC Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Aug 2016
Posts: 73
Hi folks, this is partly a question for Magnetoman or anyone else who may have fitted an adjustable magneto pinion:

Unlike the original, the variable pinion boss is not chamfered, so I was wondering if you fitted any sort of material between the pinion & case to try to stem the seepage of oil.

My timing cover has the original type (useless) felt washer and metal retainer between mag and case, but nothing between pinion and case, also nothing over the taper to impede oil ingress to the magneto. I have bought a rubber washer to replace the felt; Waller talks about fitting a "velumoid or similar material circular washer over the armature spindle...". No mention if anything between pinion & cover though.

I'd like to do what I can to reduce leakage before fitting the adjustable pinion, so would appreciate any guidance.
Cheers,
Bevan

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: Reducing oil leak into magneto
BevanC #772139 04/28/19 5:44 am
Joined: Nov 2011
Posts: 6,122
Likes: 62
Britbike forum member
Online Content
Britbike forum member
Joined: Nov 2011
Posts: 6,122
Likes: 62
Originally Posted by BevanC
I'd like to do what I can to reduce leakage before fitting the adjustable pinion, so would appreciate any guidance.
The oil leaking past the bush into the timing case on mine was excessive so I machined a holder for a thin oil seal that I clamped to a boss using a setscrew, as can be seen in the photograph. This stopped all leakage into the case for the entire ~3000 miles. The small pool of oil you see in the photo isn't from the engine, rather is from the chain lube I applied at the end of every ~300-mile day. Anyway, as a result of the oil seal the case stayed completely dry so I didn't have to worry about having a seal of any type for the magneto.

Attached Files Ariel_mainshaftOilSeal.jpg
Re: Reducing oil leak into magneto
BevanC #772189 04/28/19 7:43 pm
Joined: Aug 2016
Posts: 73
BevanC Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Aug 2016
Posts: 73
O.K., thanks for that.
I had wrongly presumed that the inner primary cases on Ariels as old as yours would have had an opening to the crankcase above the mounting boss shown in your picture, as the later singles do, so I guess the opportunity for oil leaks is less anyway. Cheers, Bevan


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