Forum

[Hugh]

As with many old bikes my bullet wet sumps if left unused for a while. Doing some work on the alternator which seems to be failing but after 60 years forgivable but there is an excess of oil (with some petrol mixed in) in the primary chain case. Question one is what seals the primary chain case fro(if anything) m the engine (my Bonneville engine oil circulates into the primary case) since as stated oil here seems to be mixed with some petrol and most importantly how easy is it to change any such seal. Given I understand some people use auto transmission fluid I assume the Bullet is a sealed system. I thus assume there is a seal behind the alternator on the end of the crank shaft but the alternator stator and rotor are not yet removed. I've lived with it for 15 years without knowing so might leave well alone unless an easy fix but suspect not. Second question is if the alternator needs changing can anyone advise which one I need to buy as I have the hexagon stator which is the original 6v but the bike has been uprated to 12v. My parts book says it is a Lucas RM14. It has however worked OK for the 12v system change. I think the hexagon stator has the securing holes in unusual places so its not just any easy swop to a more modern equivalent. Any help/advice appreciated. Hugh

[Adrian]

Hi Hugh,

our hosts' parts book and on-line manuals for the Redditch Bullets ought to have exploded diagrams for the drive side crankshaft seal arrangement.

UNFORTUNATELY it needs an engine strip to extract and replace the bits as - if the engine is still in its original condition - they have to be removed from INSIDE the left-hand crankcase, there is an alloy lip cast in to the crankcase seal housing to hold everything in place.

My '61 Bullet was also leaking from the crankcase into the primary cover, I used this as an excuse to take the engine to Paul Henshaw of performance classics for a few upgrades and some tuning. While he was working on the engine I also got him to modify the crankcase to take a proper oil seal (a Norton Commando fork seal, I believe), which can be extracted without a full engine strip when it needs replacing, hopefully not for a long time.



A friend on another forum managed to find a modern type (still imperial) seal which was a direct replacement for the Redditch set up, but it's still an engine strip to get the old one out and replace it.

Some time in the late 1950s Lucas shrank their alternators quite a bit. If you still have the great big hexagonal stator type there is no modern direct replacement for it, so when it finally does throw in the towel you can either see if you can get it rewound and the rotor re-magnetised (Try Rex's Speed Shop), or do what Redditch did and fit an adapter ring to take a more modern Lucas type, nowadays either the Lucas RM21 or Sparx 005. However they have a different part number for the 56-58 inner primary covers and the '59-61 part, so you'd want to check with out hosts whether the adapter ring fits the older inner cover.

Your other option would be to fit the inner primary cover off a more recent Indian Bullet, these are designed so that the alternator stator bolts straight on with a set of 7mm (!) studs, this stuff should be easier to get hold of.

Hope this helps,

A.

[Hugh]

Thanks Adrian very useful as usual. All this arose as the alternator seems not to be charging. It is with a specialist at the moment which obviously means cost as they dig through and as you would expect discover things I did not know about (ignorance is bliss). I have parts book for 56=57 and am using the Crankcase assembly page if you have a copy it seems like illustrations 6 to 12 are what are needed on the oiling issue. It could of course be a breather pipe pressure issue but doubt it. Anyway will get a report once alternator is off. Had bike for 15 years so may decide just to live with it as bike has performed well for limited mileage I do depending on cost plus availability of spares from our host. Using it will keep wet sumping down as it has stood for a 12 months while solved the magneto timing issue from previous post. Not sure if excess oil in P.chain case if I leave it would however damage my new alternator which I assume I will need. Thanks again for your help as appreciated. Hugh

[stinkwheel]

Parking it with the piston at TDC should eliminate or vastly reduce wet sumping, unless it's finding its way past the crank seal. If the crank pin is above the oil level, oil can't get into the sump via the quill seal.

I don't have much experience with older bullets but I'm dimly aware that in the 1950's many bikes breathed into the primary chaincase. What's the breather arrangement on yours? Might be worth looking at if it's breathing excessively.

[Bullet Whisperer]

If the engine is ok otherwise, I would just put a catch tray or tub under the engine when standing idle for longer periods, with the crankcase scavenge strainer plug removed so any oil seeping into the crankcase will be collected for reuse, without getting into the primary case.