New stablemate for the Commando

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Always liked the look of the OIF BSAs so I got a 1971 Thunderbolt today from Craigslist. Very good condition, paid $3,000, drove it around a while, usual leaks etc. Now I need a parts connection, first for a valve cover gasket. Any suggestions? Also, the previous owner topped off the oil right up to the filler cap. Is that ok?
 
ALWAYS get a parts book & a shop manual before doing much else.

I would do a full maintenance, by the book, in the order that the steps are published. In that process you are BOUND to find other things needing attention/replacement.

THEN place a complete parts order. You'll also save on time and shipping costs, 99% of the time.

British Only's website will give you a budget price, then you can check ebay. Steadfast & Lowbrow are on there, as well as a few others that do regular business. You don't say where you are, so I have no idea who would be local or close to you. Raber's, Hutchinson, Big D, any JRC reseller, etc...

Oil tank should be approx. 2/3 full in regular running. Previous owner may have overfilled it after it "wet-sumped" while sitting, thinking it was low. Oil migrates down into the crankcase sump, then floods the tank on startup, and can overflow/spew. Always check oil level AFTER running the bike; as long as you have SOME oil (at least visible above the oil intake sump filter) in the tank.
 
Oil tank should be approx. 2/3 full in regular running. Previous owner may have overfilled it after it "wet-sumped" while sitting, thinking it was low. Oil migrates down into the crankcase sump, then floods the tank on startup, and can overflow/spew. Always check oil level AFTER running the bike; as long as you have SOME oil (at least visible above the oil intake sump filter) in the tank.

"OIF" so topped up to just below the filler would be normal.

https://issuu.com/sealycycleservice/docs/pb-bsa-a65-1971_00-5722
 
I’ve gone through the ”new” BSA and have been taking it out on short runs looking for leaks and other peculiarities. Better than what I expected, and i’ve already grown fond of it. I have a question about transmission oil...Redline recommends their “Shockproof” oil for motorcycles with separate transmissions, but what would be the problem with putting it in a unit construction bike?
 
Oh, and Grandpaul, I’m in San Diego. Rocket Motorcycles and GP Motorcycles used to be the place to stop in and get British bike parts, but they’ve both moved on to be dealers for Ducati, Triumph etc, and aren’t so much into the old stuff anymore.
 
I have a question about transmission oil...Redline recommends their “Shockproof” oil for motorcycles with separate transmissions, but what would be the problem with putting it in a unit construction bike?

By "transmission" do you mean 'gearbox' or, 'primary chaincase', or both?

The engine is "unit" but the gearbox and primary drive are two separate compartments from the engine so gear oil is used in the gearbox and (originally) 10W/30 specified for the primary case although modern preference is likely to be ATF.
 
By transmission I meant gearbox. Reading on the internet tells me that oil to the primary chain case is fed from the engine crankcase, through three small holes, in the form of a mist, and that’s all it needs, so I assume if I used atf in the primary case, it would eventually be contaminated by engine oil. If the gearbox is isolated from the other cases, and it stands to reason that it is, by the very fact that gearbox oil is specified, then the Redline product should be fine.
 
Reading on the internet tells me that oil to the primary chain case is fed from the engine crankcase, through three small holes, in the form of a mist, and that’s all it needs, so I assume if I used atf in the primary case, it would eventually be contaminated by engine oil.

That is not correct so I suggest you get a copy of the 1971 factory manual (not the Haynes A65 manual) as soon as possible.

New stablemate for the Commando


Lubrication, section A12;
New stablemate for the Commando
 
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Thanks L.A.B. I’ll get that manual. I got the Haynes manual from the previous owner, and it seemed pretty thin.
 
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