User avatar
By stinkwheel
To further obfuscate the issue. Chennai engines have TWO holes between the oil tank and timing chest. One above the other. Is the top one for gas?

I'll be interested to see if my 350 bullets outrageous levels of oil consumption decrease now I've blanked off the oil tank breather hole. Could they be pressurising the entire timing side by routing engine blowpast into the oil tank? Unit single BSAs sometimes do a good job of filling their primary cases with engine oil by a similar mechanism.
User avatar
By Wheaters
I'm glad it's not only me who see the changes to the breather/s on these engines confusing, possibly illogical and somewhat contradictory!

Next step for my bike? So far the oil consumption isn't excessive and it doesn't seem to wet sump, so I'm only aiming to prevent the build up of oily sludge in the breather pipe.

I'm going to try disconnecting the troublesome catch can and fitting a non-return valve in an open breather from the top of the oil reservoir to vent onto the rear chain. If it blows oil out as well as gas I'll think again.
User avatar
By Chris Tindal
Mine has the original single duckbill from the crankcase beneath the cylinder to the rear chain. It’s always worked perfectly, in fact just enough oil mist to mean I never lubricate the chain myself. I must confess I don’t get all the catch can and pipework changes to later machines, or the need to do it.
By Aethelric
I have never had any problem with the standard breather on my 2033 model sixty-5 which feeds to the catchcan. But after reading posts here about the possible problems of a dip in the breather pipe I removed the catchcan and replaced it with the short straight duckbill to the rear chain. It seemed a simpler solution. No problems at all so far.
By Daiwiskers
Been thinking again!

Our engines were designed back in the 50s I believe that this was a rehash of a even older design!
I feel it's incredible that the Indian made bike's can get through modern emission regulations

It seems not all bike's suffer from breather problems or wet sumping
My own bike doesn't suffer from the breather problems now but still suffers from wet sumping

Is the modern oil to blame for our problems?
I run a mineral 20w50 in both bike's

When our engine's were designed multi grade oil wasn't available in the summer you would run a thick oil in the winter you would run a thinner oil

Has anyone ever used a mono grade oil and has this helped?
As I mentioned in another post are modern oils too good for our engines keeping the engines cooler allowing condensation to develop?

The answer must be out there
Cheers Dai
User avatar
By stinkwheel
I suspect there is a simpler explanation which is twofold but boils down the same thing as was the case with most British motorcycles. ie. They were never particularly good and all had problems, usually at a fundamental design level. If they didn't, the factory workers could be counted on to engineer one into them at the point of assembly.

The two parts of the explanation boil down to:

1) All the "original" bikes that are about now have been filtered through long use, repeated fettling and a natural selection process meaning all remaining ones are the very cream of what was produced. How many got pushed into a ditch/taken to the scrappy/got a match in the tank before we got to where we are now?

2) A heavy varnish of nostalgia. "Bikers" from the 50's and 60's had black fingernails and oily pockets implying their bikes required regular fixing.
By Beezabryan
Well now Stinky, judging from your unabashed cynicism you must have bought a real basket of lemons over the years.
User avatar
By Wheaters
I can't think what he means. My old BSAs sometimes went as long as a week without needing any spannering attention. :D
User avatar
By Presto
Lots of fun subjects here – British bikes, engine oil, nostalgia! What more could we hope for?!

It’s unreasonable to complain about British motorcycle design across the board or even ‘most’ British motorcycles. There are countless excellent designs, ground breaking and world beating. Of course they are endless examples of idiotic designs too! But that’s equally the case with German, Italian and even – shall we admit – Japanese designs! I think it can be argued (probably endlessly and to no worthwhile point!) that the problem should be laid at the door of accountants. The poison then crept into the boardroom, management and finally onto a fatal demoralised workforce.

Stay well away from monograde oils in a Bullet – or in anything else for that matter! Multigrade oil cannot of itself produce wet-sumping or breather problems. And the notion that multigrade oils decay bushes and bearings is so much nonsense. It’s safe to use – far ‘safer’ than monograde – in any four stroke motorcycle. Also I’m unconvinced of the need of a dedicated ‘motorcycle oil’ as opposed to a generic multigrade of the correct viscosity. ;)

As for ‘black finger nails and oily pockets’ – regular careful maintenance and empathetic riding would be my answer. (That process also prevents choke slides ceasing up in Mk1 Concentric carbs!!). :o
User avatar
By McMurdo
""Bikers" from the 50's and 60's had black fingernails and oily pockets implying their bikes required regular fixing."

Hey, don't knock it! I bought my "Dirty Bertie" when I retired because there was never anything to do with my Hinkley Bonnie. Now my winter days are spent getting black fingernails and oily pockets in my shed. My wife appreciates my absence too but I haven't worked out if that's a good thing yet ...

Shop for accessories at Hitchcocks Motorcycles