Motorcycle General Discussion

Only the short lived 8 valve head TSS Bonneville had the rocker shafts supported in the head casting, but still with seperate covers. This at least stopped the pushrods from trying to lift off the rocker covers. The standard four valve engines retained separate individual rocker boxes containing the rocker shafts.

BSA unit twins were better with rocker shafts in the head, and a nice large one piece finned cover. You know, I am beginning to like BSA's more and more. I have never ridden a BSA twin, in fact I had never ridden any BSA until I bought mine a few months ago.

BSA stopped building bikes in 1973, so by the 1980's, when I was riding bikes, most BSA's I came across were broken non runners festering away at the back of people's garages and sheds. The bikes I bought had to be working bikes, as I rode them as everyday transport all year round. Good working Triumphs were plentiful and I had quite a few of those, plus one T150 Trident, and some great Japanese bikes of the 70's and 80's. So BSA's have always been a bit of a mystery to me, until now.

Edited By Lathejack on 01/11/2015 23:14:24

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Edited By Lathejack on 01/11/2015 23:38:35

Maybe a little short on ground clearance?

Wooden bike wooden corner?

I never could keep any of my triples' top ends oil tight for very long. Yet the 750 Bonnie I had was never a problem. And my Harley Sportster has the same sort of detachable rocker boxes that hold the rocker spindles and it has never leaked. The Harley will squeeze the gasket out if any kind of sealant is applied to the gaskets but fitted dry they work 100 per cent. But I tried everything on those triples and never could get them to stay clean and dry for more than a few thousand miles.

British bikes = oil leaks. Complete fallacy. Only std factory bikes. When rebuilding, it is not only renovate, repair, replace, but blueprint, blueprint, blueprint. You will then have an oil leak free British motorcycle. The same can be said for 60's-70's British, American and Italian electrics. Purchase the motorcycle, rip the std wiring harness out, bin it, and blueprint the electrics and add a custom harness.

Back in the day, Norfolk Police had Moto Guzzi 850 T3 police bikes, at 50k miles, they were auctioned off. Many of my friends purchased these, ripped the harness out, re-wired, and had a completely reliable motorcycle that would go anywhere inc long trips abroad with zero problems for another 50k with minimal basic maintenance. Thats 100k miles without lifting the heads.

Agree, Triumph rocker box design can be made long term oil leak free. Gaskets, design and materials have moved on in the last 20 years for Brit bikes, compared to the std crap that was available prior by the original manufacturers.

with careful assembly any british engine will be totally free of leaks and reliable,none of my old panthers leak and my normal transport a 1937 panther mod 85 has now done 20.000 miles in the last couple of years cruises at 70 has 12 volt electrics (old dynamo i converted ) and has been totally reliable the old mz leaks more from the gearbox than the old ones , i have one that leaks a 95mph 250 panther racer but as there are no covers to keep the oil in i know when it stops leaking its time to bung some more castrol r in, will

As a long time motorcyclist with a few bikes I have been reading this general discussion with more than a little interest. I have very strong views about leaking British bikes. I have a few in my garage, and have until a year ago had a lot more. My garage has fitted carpet and as you can imagine oil leaks would be a major problem. They have all been rebuilt, except for my 2012 Triumph Thruxton and my recently purchased Triumph 5TA Speed Twin. The former does not leak and the latter is currently on my work bench awaiting some serious spannering. In order to prevent my bikes leaking I have a very simple technique...............if they have the audacity to drip oil, I shout at them very loudly. They don't do it again.

Whilst I read this site every day, and occasionally post on here the truth is that I do not make models. My machines are used to make parts for my bikes and for friends bikes, mostly in stainless steel.

It's good to see so many motorcyclists on here. Long may it continue.

A nice model Harley Knucklehead. Not mine, but found on the net some time back. Built by Jerry Kieffer in the USofA, over about eight years. More pics of the finished model here

**LINK**

Even the speedo works!!

I think Les Williams knew a bit about building Tridents but probably the most famous production racing Trident Slippery Sam, built by Les got its name from a bad oil leak. Blueprinting a flawed design will not solve a fundamental problem.

Mike

Even the works wooden ones leak oil, shouldn't that be sawdust ?

My 1969 Triumph Trophy is sort of oil tight since its rebuild. Only problem is the alloy head seems to be sponge-like. Doesn't leak oil from any of the joints, but it's become porous from age, and weeps small amounts of oil where there are no joints. Not uncommon apparently.

I had a 69 BSA Thunderbolt in about 1973 that had the same problem. Found out years later that there was a big batch of porous head castings that year. Probably the same supplier for both factories.

Beadblasting the inside of the rocker cavities and rocker boxes and painting them with Glyptal (sp?) casting sealer paint is a common solution today. But we didn't know anything about either of them back then.

Custom Pan Head Chopper "Wood" Here

Mike.

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.

Mike

" 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."

Yep, and I'm nearly 70 and proper bikes don't have electric start and indicators despite Mr Honda's "Dream".

On the Hardly theme, there's a British HQ for one of the international bike groups about 700yds from me. Despite the derision on the Yankee twins reliability, a few years ago they had some sort of "Meet". Like a flock of vultures, on the Saturday afternoon, they decided to depart and although they might have broken down at the end of the road, the peace was disturbed for at least five minutes solid (NO exaggeration) with thunderous Vee-twins two and three abreast hurtling past the house, and no, they weren't going round the block and back again. Pity I didn't have a camera available at the time. Sound wise, remember the Luftwaffe dispatch in front of Goering in "Battle of Britain".

Regards Ian

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.

Shaun

Re oil leaks- 2CV's horizontal twins, seldom leak oil, due to the layout and a very good, simple ,breather valve. Old Triumph twins- our cure was to wear a welly on the right foot.

Not too long ago I got stuck behind a bunch of brand new V twins without silencers, spread out all over the road for about ten miles coming out of Plymouth. The racket was so bad, I had to rely on the tach. to know when to change gear though the 500 single wasn't that quiet either. In the end I had to pull over with concussion and a splitting headache from the battering to let them get clear. They all looked like off duty, mid life crisis accountants, dressed for the golf course in shorts and T shirts, waiting for a dose of road rash.

I think my "real motorcyclist' prejudice is showing……. Or maybe it's just jealousy 'cos I can't ride anymore.

Ian

When I worked in gas turbines (a very long time ago!) we used to have aluminium castings vacuum impregnated with resin to prevent any porosity issues. Whether there are still firms who do this, and whether it can be done when the casting is already soaked in oil I do not know