1970 A 65 L oil pressure switch

Hi All.

Anyone knows what is the correct PSI of the oil pressure switch of the 1970 A65 L?.

It happens that when the bike is warm (after a half hour of use) the oil pressure warning light switch on under 3000 RPM. 

Could be faulty the switch or is it with a PSI too high; the oil pressure switch is not the stock one (196508 / 5307/1/07) but one i have bought new.

I have a part another stock oil pressure switch but it is 5300 like for 1971 OIF type engine as the parts list says.

What is the differences between 53007 and 5300?

What i have to check?

Or could be the oil pump faulty?

Thank you.

Ciao

Piero

pierodn said:

Hi All.

Anyone knows what is the correct PSI of the oil pressure switch of the 1970 A65 L?.

Click to expand...

5 PSI according to the factory manual (Smiths PS5307/05 switch).

pierodn said:

It happens that when the bike is warm (after a half hour of use) the oil pressure warning light switch on under 3000 RPM. 

Could be faulty the switch

Click to expand...

It could be, or could be low oil pressure?

pierodn said:

or is it with a PSI too high; the oil pressure switch is not the stock one (196508 / 5307/1/07) but one i have bought new.

Click to expand...

07 = 7 PSI.

pierodn said:

I have a part another stock oil pressure switch but it is 5300 like for 1971 OIF type engine as the parts list says.

What is the differences between 53007 and 5300?

Click to expand...

5300/1/07 is NPS (parallel) thread
5307/07 is NPTF (dry-fit tapered) thread.

pierodn said:

Or could be the oil pump faulty?

Click to expand...

That is a possibility, however, it is not the only one.

Re: 1970 A 65 L oil pressure sitch

Hi Les,
Thank you.
Ciao
Piero

I experienced the same thing with a 1969 Lightning I had. I plumbed an oil pressure gauge into the pressure switch orifice and determined that pressure was fine. The pressure sender unit was faulty. It wasn't a Lucas sender. I found that OEM Lucas senders are rather hard to find, but can be found. Your oil pump has to be very trashed not to produce over 5# pressure. Sometimes it can be caused by the pressure release valve being stuck open.

lazyeye6 said:

The pressure sender unit was faulty. It wasn't a Lucas sender. I found that OEM Lucas senders are rather hard to find, but can be found.

Click to expand...

Original oil pressure switches fitted to the vast majority of British motorcycles, including the A65, were made by Smiths, not Lucas. :wink:

Best check is to attach a pressure gauge to the pressure switch port temporarily and see how pressure behaves while oil warms up during riding.
You could use pneumatic push-in fittings and 6 mm nylon line, they hold.
Easy check is the relief valve, more info here for example: http://www.a7a10.net/BSA/oilrelief.htm.