By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Motorcycle General Discussion

All Topics | Latest Posts

Search for:  in Thread Title in  
JA11/11/2015 16:49:09
1214 forum posts
73 photos
Posted by Involute Curve on 11/11/2015 13:52:53:

A breather valve from a modern bike pretty much cures a lot of porous casting leaks, and helps enormously with all oils leaks on old classic bikes, most parallel twins tend to pump up the crank cases effectively forcing the oil out, these valves create a vacuum which helps a lot, and its easy to do.

What still puzzles me, is how come Triumph BSA etc. became the last survivor of the British bike industry, if you visit the bike museum at Birmingham, other manufacturers stuff was way ahead of both, in quality and design, I can only guess it was political or bad management or both.


The breathers on my old bikes, all the same make, try to keep the crankcase pressure below atmospheric. They don't prevent oil leaks though.

Edward Turner was an amazingly good salesman.


Windy11/11/2015 17:00:40
869 forum posts
185 photos

There are many sealants for porous castings available here is just one


In my younger days when the solo and side car racing guys were using outboard Konig engines the castings could be porous here are a few pictures of them in racing motorcycles





Edited By Windy on 11/11/2015 17:02:34

Involute Curve11/11/2015 17:45:30
337 forum posts
107 photos

I have three very good friends who own Triumph's inc twins and triples, plus two of them own Norton Commando's, none of them leak oil at all, both Norton's I have witnessed do 250 mile trips at very good road speeds and not a drop to be seen, both Norton owners have had bikes in the final of Classic bike of the year competition, run I think by Classic bike, all three state "if you put them together properly they don't leak!!" and to be fare I can't argue with them because there's don't........... one even has a mock oil patch he made from resin which he enjoys placing under my MV.....

The only British classic I have left myself now is a Velo, which does leak, but its a1956 MSS in original condition, which I may get round to restoring one of these day's


Mike Poole12/11/2015 00:14:18
3047 forum posts
72 photos

I think the oil tightness of a Brit bike depended not only on how it was put together but how hard it was used and abused. I know people who claim 40mpg from a trident, a figure I have never achieved, 30 was about the best and 18 the worst, the race home after a club night meant giving it 10/10ths from cold which is mechanically most unsympathetic. Giving a V4 Honda the same treatment did not result in oil leaks but brake fade did appear after 5 roundabouts in 2 miles, a bit of a worrying moment the first time it happened. Top end gasket sets seemed quite affordable even with a solid copper head gasket, and a day's work for a top end strip and rebuild used to seem like fun, a top end gasket set for my Hinckley trident was over 100 pounds, not money you would want to spend on a regular basis.


Hopper12/11/2015 01:13:59
5505 forum posts
137 photos
Posted by Michael Poole on 11/11/2015 11:16:06:

Sound like a good ride Hopper, 6000 miles in the UK is not a trip you can easily make, the four points of Britain is only about 2500 miles. Other trips are on though once you get over the channel like how many countries you can visit in 24 hours. I see Harley's as bikes for wide open spaces like the US and Oz, in the UK i feel there are better tools for our type of roads. However there is a significant number of Harley's in the UK and a lot do fit the weekend warrior model that I mentioned. This always provokes a lively debate like the Brit vs Jap argument that still rumbles on even though I was a youth when it started and am now nearly 60.


LOL yes the whole distance thing is totally different, and the HDs are much more suited to the wide open spaces. That's why I keep a Honda VFR800 in the shed just for the twisties. Although, the old '77 HD Sportster with modern tyres on it is no slouch through the twisties, for its era. (No brakes to slow you down!)

Yes I think if I lived in the UK, rides to Istanbul and back via various routes would be a regular thing. Awesome to be able to get off one's own island and ride through other countries. Closest I get is renting a step-through Honda 110 in Bali occasionally, which is actually more fun than you would expect on a step-through. .

And 30mpg was about all I ever got out of my Tridents and Rocket 3s. Worth it for that beautiful exhaust note though. Had a 3 into 1 on the 71 Rocket 3 sans baffles and it was glorious.

Edited By Hopper on 12/11/2015 01:15:42

Fowlers Fury12/11/2015 21:24:35
379 forum posts
87 photos

I like this thread - the newsgroups on 'bikes have deteriorated greatly whereas this looks promising !

Just as Nick Berrisford posted "Bloody typical, a bike thread is started just as I have had to call it day after 40 odd years of biking". Likewise, I decided I was too old for the big BMW, sold it and now wish I hadn't. I've kept all the riding gear so delude myself I haven't totally given up on the idea of getting another bike.

Prior to the big BMW, I'd rebuilt quite a few Brit bikes and the pride & joy was undoubtedly my Panther - sold on about 20 years ago :- (

1955 M100 600cc Panther single


For me, the best perspective on the demise of Brit bikes is still Bert Hopwood's book "Whatever Happened to the British Motorcycle Industry".

John Stevenson12/11/2015 21:42:56
5068 forum posts
3 photos

If we had discovered North Sea Oil 10 years earlier then the British motorcycle industry would have managed to survive a lot longer. wink

Don't know about others on this forum but my workshop was initially setup to work on racing motorcycles and later it progressed to more commercial avenues. I take MEW, used to take ME but when MEW was spun off it suited me a lot better. I do not build models and many of my friends also have workshops but none of them build models either.

Their workshops are there to support another hobby, usually vintage bikes or cars.

Currently do not own any bikes and if I did they would be a work in progress and then passed on. Never really been interested in riding other than a method of getting from A to B

thaiguzzi13/11/2015 06:03:05
703 forum posts
131 photos

Good thread. Keep it up chaps.

Like John, i have no interest in models. I got into machine tools by needing to make stuff for motorcycles myself rather than farm it out. Then later on in life, i got into the machine tools themselves. And the tooling...

Hopper13/11/2015 08:42:29
5505 forum posts
137 photos
Posted by John Stevenson on 12/11/2015 21:42:56:

If we had discovered North Sea Oil 10 years earlier then the British motorcycle industry would have managed to survive a lot longer. wink

If everyone still rode Brit bikes, you wouldn't NEED North Sea oil, plenty of it splashing around everywhere on the roads.wink

Chris Evans 613/11/2015 09:38:56
1948 forum posts

I do not build models, my workshop is for motorcycle related stuff. I get to see a lot of old British stuff and think most oil leaks stem from incompetent people. Witness marks from pry bars/screwdrivers where parts have been disassembled. Fitting a BMW breather valve in the return oil line really helps with crankcase pressure related problems. Chris.

Circlip13/11/2015 12:24:24
1327 forum posts

Good luck to anyone trying to make a Velo oil tight. The bashed tin chaincase was a rather poor piece of engineering design, but with the outside final drive sprocket, a nightmare to do better. Oil tightness not only restricted to Brit products although the "British Empire" did allow us to export c**p to many parts of the world with impunity.

Regards Ian.

Ian Abbott13/11/2015 14:58:30
279 forum posts
21 photos
Posted by Circlip on 13/11/2015 12:24:24:

Good luck to anyone trying to make a Velo oil tight.

Dunno', Velo chaincases were fine if they were assembled carefully. The only Velo leak I ever had was where some amateure mechanic had stripped out the valve cover mounting threads in the alloy head. I pulled the tank and drilled them out around 5/16" and fitted steel threaded inserts, filed them flush, then drilled them BA for long cheese head Allen bolts. Never a drop leaked, until the railway crossing modified a lot of the engine parts.


Gordon W14/11/2015 09:42:32
2011 forum posts

Velo' chaincases were supposed to be filled with grease and oil mix. Grease in first, run the engine for a minute or two, this is supposed to fling the grease into the outer edges and seal the joint, then top up with oil. Worked quite well on mine.

Circlip14/11/2015 09:58:34
1327 forum posts

And the "Seal" between the chaincase and engine crankcase?

Felt washer and the will of God.

Regards Ian.

Hopper14/11/2015 11:57:23
5505 forum posts
137 photos
Posted by Circlip on 14/11/2015 09:58:34:

And the "Seal" between the chaincase and engine crankcase?

Felt washer and the will of God.

Regards Ian.

A seal? Felt washer? Oooh, they were luxury they were. My old 1942 Harley doesnt even pretend to try to keep the oil in the chaincase. It is open at the back, with a half-inch high flange along the bottom. When the oil level, supplied by the primary chain oiler, reaches half inch deep, it simply overflows onto the ground. And everywhere.

The back chain has its own oiler too, so the gearbox sprocket cover has a large square hole in the bottom of it so excess oil and chain gunk can drain out, straight on to the exhaust pipe below! I think they had a different attitude to oily machinery in them days.

Michael Gilligan14/11/2015 13:06:13
18694 forum posts
911 photos
Posted by Fowlers Fury on 12/11/2015 21:24:35:

... the pride & joy was undoubtedly my Panther - sold on about 20 years ago :- (

1955 M100 600cc Panther single



Thought you might like to see this one smile p



Taken at the Bugsworth [aka Buxworth] Steam Party, this year.

I had always typecast Panthers as grubby old things laboriously hauling sidecars

BUT this one was something else !!


Michael Gilligan14/11/2015 14:51:57
18694 forum posts
911 photos

Given the 'chaff' that has been flying for the last couple of days ... I fear that this introductory post may have gone un-noticed.

Welcome, Gary ... I'm sure we would like to see some photos of the bike !!


Edited By Michael Gilligan on 14/11/2015 14:54:42

Fowlers Fury14/11/2015 16:48:42
379 forum posts
87 photos

> Michael Giiligan.

Thanks for posting those pics the Panther. I think it's a 1930 Model 50 from a quick scan of Barry Jones' book "History of the Panther". So ~ I'll excuse your derogatory comment about "grubby old things" tho' I have to admit there were a lot of 'rat bikes' at the Panther rallies !!.

One picture in Barry's book always amuses me.


Certainly for the 'bike restorer with a parallel interest in model engineering, life is quite a bit easier. I remember having to fabricate new oil feed pipes and instead of paying to get the copper chrome plated, I tried Rex Tingay's method in M.E. for silver plating clock faces. The result looked excellent providing you didn't use chrome cleaner on them !

I still have the first 6 years of "Motorcycle, Scooter & 3 Wheeler Mechanics" (reminder to myself to put 'em on Fleabay sometime). and it's fascinating to read the dodges & bodges in the mid 50s suggested to keep your bike on the road. All the postings here about keeping chain cases oil tight reminds me of one. It was suggested that after reassembling, you should lay a candle in the primary case and gently heat with a blowlamp until the candle melted. Fish out the wick, and when cool the solidified wax would effect a seal. Doubt it would have done much for the paint but it may well have worked.

gary14/11/2015 17:02:25
133 forum posts
31 photos

hi fowlers fury, is there any truth in the story about panthers firing at every second fence postlaugh

BC Prof14/11/2015 17:15:23
159 forum posts

The version I heard 50 yrs ago from a sidecar and Panther combo owner was " Bang every lamp post "

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
rapid Direct
walker midge
Eccentric July 5 2018
JD Metals
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest