66 BSA reccomendation

[feliz]

Greetings. I've been lurking here since the forum's inception, finally signed up, and now I'm seeking advice.

I've just purchased a 1966 BSA lightning which is a 650 parallel twin with seperate chain/clutch and gearbox cases. The motor has 1500 miles since a total rebuild by a trusted mechanic who is also the former owner. The previous owner had 20-50 in the engine, not sure about the chaincase, and Redline gear lube in the gearbox.

The manual calls for 40-50 for summer and 20-40 winter with 2000 mile OCI.

Gearbox calls for SAE 50. The Haynes manual says to use 90 gear oil which is what the previous owner was using. The primary chaincase calls for SAE 20 motor oil. I was thinking Rotella 15-40 in the engine and chaincase and 90 gear lube in the gearbox. I like Rotella and use both dino and T6 in my newer bikes. This bike is pristine and I'd like it to last as long a possible. Suggestions or comments appreciated. Thanks

 

[fdcg27]

Was this built during the period where BSAs were really badge-engineered Triumphs?
Just curious.
I'd think that the Rotella would work well.
The oils of the mid 'sixties and the oil recommendations of the Brits from that time were probably not very good.
It's also not as though you're likely to ride the wheels off of this nice old period piece.

 

[BusyLittleShop]

If your clutch was new a 40 might prove serviceable but a 1966
clutch in a unknown worn condition I recommend staying with a
straight 20 or a 0W-20... at least with the correct viscosity
you can blame the clutch and not the oil... you might seek the
advice of a old gear head who knows how to recondition worn
clutch plates...

You see back in the 70s clutch maintenance use to be part of every savvy rider's
maintenance plan... and for some reason that all change during the
90s... why fix what you can buy new is the what you hear now a days...
but if your interested in making your clutch bite good as new then
roll up your sleeves and read on... for the rest of you... get back on
the couch...


It's a fact that all motorcycle wet clutches will reach a point in
their life and begin slipping... the first signs happen during WFO
throttle (Wide Fooking Open)... Don't be surprised if you tear a part
the clutch pack and note that the plate thickness is well within
specifications listed in the shop manual... What you will notice is
the glazed appearance on the surface on the friction plates...




Inspect the friction plates for glazing... make sure you have plenty
of material to work with... the VFR manual states clutch thickness
in thousands of an inch... I don't a manual handy or I'd list the numbers

First removed the contaminants with something like Acetone... then lay
each plate over a 600 grit black dry emory paper and rotate in a
circle... you're just busting the glaze... don't get carried away
remove too much material... You should end up with a friction plate
looks dull like a new one as opposed to a shinny glazed one... recheck
thickness...

Next check the pressure plates for bluing caused by localized heat...
make sure they are not warped... the manual does not state a thickness
range... now removed the contaminants with something like Acetone
and wire wheeled them to erased the blue and also to generally scuff
up the surface... you should end up with a dull surface free of Blue
marks...

 

[Robenstein]

The BSA 650 and the Triumph 650 twins were not the same. You can still get SAE oils that are spec'ed for the chaincase and primary, but your choice of Rotella 15w40 for the engine would be heads and tails above anything there was for oil when the bike was new.

From my understanding the weak part of the BSA twins were they used a bronze bushing on one side instead of a bearing, and that is where the weak link in them is versus the Triumphs.

 

[Silk]

Later models breathed into the primary case, so engine oil is ok in there, but ATF would be good too...if you can hold it in. In NZ I'd probably use 20-50, but a HDEO 15-40 might be better. The A65 was a total redesign, and a vast improvement over the A10, and in some ways better than the Triumph which only had detail changes with unit construction. What I liked about the A65 was a triplex primary chain (and Triumph clutch), no rocker box, and a cassette gearbox...the gearbox also had just one part number for the sliding dog gear - it was used for 1st and 2nd, and also 3rd and 4th, and it was also reversible.

But they kept the bronze bush for the timing side bearing, perhaps they didn't see it as a problem, and if well looked after it shouldn't be. The '72 engine, which was the last, had an oil pump with 25% more capacity. Someone who knew their stuff would maybe have fitted the later model oil pump.

 

[Trav]

I had both together for a time and used 50w in them both back in the mid 70's.
The multigrades seemed to weep more than the mono grades probably due to seal materials of the day. With a recent rebuild i would try the 20w50 today

 

[feliz]

Thanks to everyone for their responses, lots of good information.
Yes, a later oil pump was fitted. As far as bing a rebadged Triumph I think that's backwards, BSA owned Triumph at that time.

I much prefer this bike to my 71 Norton Commando, the only other old Brit bike I've owned. I'm going to go with Rotella in the engine and chaincase and pick up some 90 gear oil and see how that goes.

Here's the beast if anyone is interested. Thanks again.

 

[tc1446]

What an absolute beauty! Thanks for sharing. I still often think of my days back
in the 70's when I had a Norton Commander, the only British bike I ever owned.

 

[toneydoc]

Beauty. Are you going to ride her much or often?

 

[DB_Cooper]

The BSA and Triumph engines were very different. The BSA twin was a better design in my opinion...

There are only three gaskets that can leak oil on the top end of the BSA..the cylinder base gasket..the head gasket and the rocker cover gasket.

The Triumph engine had external pushrod tubes front and back, four seals..two rocker covers and two rocker assemblies..four gaskets on the later engines or earlier engines had four inspection caps..four more gaskets with the two rocker gasket assemblies..one head gasket and one base gasket...lots of gaskets/seals to leak oil on a Triumph.

 

[feliz]

Thanks for all the responses. Yes I will ride it in fact I just got back from a 100 mile jaunt. Except for the bad mirrors and me crunching the gears the odd time it was pleasant. I'm well aware of the pitfalls of British bikes having owned a 71 Commando and a Triumph but this ride reminded me of why many continue to be legends........handling. Thanks to all who responded.