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Messages - cee-b

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Singles / Re: C15 - another oil feed problem
« on: 02 August, 2017, 14:23:45 »
Thanks Julian,
taking your points 1 at a time:

1. The supply is on the outer (RH) pipe of the connector block. This is the way it is shown in my BSA service sheets and, as the scavenge oil goes in the right direction, I can only presume it is correct.

2. All pipes are new and not trapped.

3, 4 & 5. I followed your advice and did this.

I ran the bike again - no change.

I have jury-rigged a clear plastic bottle with a direct feed to act as an oil tank to rule out any feed problems from the bike's tank. Using this method I can confirm that the oil level does not drop with the engine running - the oil pump is not drawing oil.

Either my priming method does not actually work or the pump is sucking air in.

Looking at the Service Sheets, stripping the engine to get to the oil pump seems a bit daunting (I am new to all this). Is it within the scope of a novice bike mechanic or do I need to be looking for a proper spanner monkey who knows classic bikes?

Singles / C15 - another oil feed problem
« on: 01 August, 2017, 21:33:43 »
I have a recurring (and very baffling) oil feed problem and would appreciate any help please.

The story so far:

I have checked that the oil flows freely (though surprisingly slowly) from the oil tank. The filter is clear and there are no blockages. The tank vent is fully functioning. I have changed to 15W30 fully synth oil as it is the thinnest (therefore fastest flowing) oil that I have.

I have primed the pump by removing the spark plug and turning the engine over on the kick start while pushing oil under pressure down the pipe from a syringe. Oil flows into the pump on cranking and oil returns through the scavenge line to the tank (all pipes are clear plastic so I can see the flow).

On starting the engine, oil can be seen feeding up the scavenge line to the tank return and to the rockers etc. Because this oil is slightly aerated, it is easy to see that it is flowing. I cannot see whether the oil in the supply line is actually moving as it is quite clear and un-aerated.

This continues for a short period - possibly up to a couple of minutes. After this period, the scavenge line begins to show large air bubbles in the oil flow and the supply line has large air bubbles appear from the pump end and float up toward the oil tank. Oil clearly stops flowing to the pump at this point and the pump becomes airlocked.

Following this, the pump will not work until the priming process is repeated.

I don't really want to have to split the engine and start investigating the pump unless I really have to (and the pump appears to be working when I turn it by hand.

Any thoughts please guys?

Singles / Re: C15 oil feed problem
« on: 28 July, 2017, 14:44:59 »
Thanks OM15 (ex-RAF 'rigger' by any chance?).

I have put a smaller sleeve inside the the tank return and it has achieved exactly that. I now have a nice balance between scavenge and feed to the rockers - happy days.

Singles / Re: C15 oil feed problem
« on: 27 July, 2017, 22:33:41 »
Thanks for the response Grumps, I was wondering if it might have something to with diameters and relative resistance to flow.

The bike has been extensively messed about with and 'restored' by the previous owner(s) and the oil pipes are now mainly clear plastic tubing.

The return to the tank is full bore of the plastic pipe, but the line to the headers goes into a length of the original diameter copper pipe, which is considerably smaller. Exactly the opposite way around to how it needs to be.

It looks like I need to do some 'fettling'

Singles / C15 oil feed problem
« on: 25 July, 2017, 19:16:13 »
I have recently bought s 1961 C15T and have a problem with the oil feed.

The oil pipes are routed according to the w/shop manual. The pipe from the return pump goes to a to a T piece, with one line leading to the tank and the other to the top end of the engine.

The problem is that all the oil is being scavenged to the tank and none is going to the top end. I cannot see why it should. Despite this being the way the manual says it should be 'plumbed', I can't see why the oil would continue uphill to get to the rockers etc, when it has an easier route to just return to the oil tank.

What am I missing here??


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