Oil Pressure Gauge or light?

Information relating to the Matchless G9 or AJS Model 20 500cc twin
User avatar
Posts: 619
Joined: Sun Nov 25, 2012 9:40 pm
Location: Chipping Norton

Re: Oil Pressure Gauge or light?

Postby leswaller » Mon Jul 27, 2015 8:30 pm

Yes this is the iron john unit. He phoned me a couple of months ago when I was after a crankshaft and was trying to sell me one of his units.
I will post a photo of my unit tomorrow
Les
Rules are for the obedience of fools and the guidance of the wise

Member
User avatar
Posts: 3592
Joined: Mon Jan 01, 1990 12:00 am
Location: LONDON UK

Re: Oil Pressure Gauge or light?

Postby clive » Mon Jul 27, 2015 9:10 pm

Rob Harknett wrote:Would you trust a light or gauge, which could go wrong. Our old bikes will sump oil when standing, some more than others. So having an oil tap does help prevent this. You have a petrol tap you have to remember to turn on. Put a key ring on the tap below the tank. You will feel this as a reminder to turn oil on & off also.

I have at least 4 friends whose fail safe systems to remind them to switch on the oil have failed, wrecking their twin engines. If you have ever ridden off forgetting to turn on the petrol then forgetting the oil tap is significantly worse than coming to a temporary halt.
clive
if it ain't broke don't fix

Member
User avatar
Posts: 10142
Joined: Mon Jan 01, 1990 12:00 am
Location: ESSEX UK

Re: Oil Pressure Gauge or light?

Postby Rob Harknett » Mon Jul 27, 2015 9:59 pm

clive wrote:
Rob Harknett wrote:Would you trust a light or gauge, which could go wrong. Our old bikes will sump oil when standing, some more than others. So having an oil tap does help prevent this. You have a petrol tap you have to remember to turn on. Put a key ring on the tap below the tank. You will feel this as a reminder to turn oil on & off also.

I have at least 4 friends whose fail safe systems to remind them to switch on the oil have failed, wrecking their twin engines. If you have ever ridden off forgetting to turn on the petrol then forgetting the oil tap is significantly worse than coming to a temporary halt.


Yes these fail safe systems are all very clever until they go wrong. I always remember to turn the petrol on before I start my bike, why not the oil tap also. I may sometimes forget to turn them off, even if its some time before I discover this, at least oil going in my engine has caused no harm. Do make sure you fit an oil tap with an I/S dia. same as the pipe. I have been told some cheap ones have small dia holes.

User avatar
Posts: 619
Joined: Sun Nov 25, 2012 9:40 pm
Location: Chipping Norton

Re: Oil Pressure Gauge or light?

Postby leswaller » Tue Jul 28, 2015 9:22 am

Here is the photo of my system. As the tap is designed to feed water to a washing machine the inside bore is big. There is no way of starting the bike with the tap off as the default position on the courtesy light plunger is 'continuity' which earths out the mag. You can see the plunger above and to the left of the red ear on the switch. Turning the tap on (ear vertical) depresses the plunger and breaks the earth connection allowing the mag to work.
You do not have the required permissions to view the files attached to this post.
Les
Rules are for the obedience of fools and the guidance of the wise

Member
Online
Posts: 6258
Joined: Wed Sep 01, 2004 12:00 am
Location: WEST SUSSEX UK

Re: Oil Pressure Gauge or light?

Postby SPRIDDLER » Tue Jul 28, 2015 2:58 pm

Image
I poke badgers with spoons.

Posts: 633
Joined: Thu Feb 27, 2014 9:27 am
Location: Kent, England

Re: Oil Pressure Gauge or light?

Postby JimFitz » Tue Jul 28, 2015 6:05 pm

Hi Les

Thanks for the pic - difficult to see much detail on method of construction. Did you use a 90 degree angled valve with a wallplate and then mount an angled plate on the wallplate with a hole in for the push switch?

Jim
Too old to Rock and Roll but too young to die.

1952 G80 rigid, 1960 G12 DL / Watsonian Monza, 1954 G80S.

User avatar
Posts: 619
Joined: Sun Nov 25, 2012 9:40 pm
Location: Chipping Norton

Re: Oil Pressure Gauge or light?

Postby leswaller » Tue Jul 28, 2015 8:12 pm

Hi Jim
There is a short rigid copper pipe silver soldered into the outlet pipe from the oil tank. This connects via an olive fitting to a straight inline tap (no mounting bracket). The outlet of the tap goes to a 90 degree olive fitting elbow and then to the conventional flexible oil pipe to the pump.

The switch is mounted on an L shaped fabricated bracket that is bolted through a convenient hole in the frame which I think would have originally been part of the arrangement for fitting a side car. The electrical earth is provided by this bracket. One connection goes to the mag cut out and another connection on the same terminal goes to the engine kill button. When the tap is turned off the switch is spring loaded in the default position and all connections are earthed. When the tap is turned on the earth is disconnected from the mag but the mag can be earthed by pressing the kill button.

I have also fitted a full flow oil filter in the return from the pump. This is hidden in the top of the frame behind the spine tube under the seat. It is cartridge based (2CV type) and the cartridge is easily unscrewed for changing by removing the seat.
Les
Rules are for the obedience of fools and the guidance of the wise

Posts: 633
Joined: Thu Feb 27, 2014 9:27 am
Location: Kent, England

Re: Oil Pressure Gauge or light?

Postby JimFitz » Tue Jul 28, 2015 8:30 pm

Thanks Les. Job for me over the winter together with an oil filter.

Jim
Too old to Rock and Roll but too young to die.

1952 G80 rigid, 1960 G12 DL / Watsonian Monza, 1954 G80S.

User avatar
Posts: 59
Joined: Mon Jun 08, 2015 7:56 pm
Location: Milano, Italy

Re: Oil Pressure Gauge or light?

Postby sunnybob » Sun Jan 21, 2018 1:37 pm

Still working on the idiot light idea. I have a question about pressure. Is the inlet oil pressure the same of the outlet?
Thank you.

Roberto

User avatar
Posts: 619
Joined: Sun Nov 25, 2012 9:40 pm
Location: Chipping Norton

Re: Oil Pressure Gauge or light?

Postby leswaller » Sun Jan 21, 2018 4:59 pm

No, the principles of any pump rely on creating a lower pressure on the inlet side caused either by piston suction or gear rotation
Les
Rules are for the obedience of fools and the guidance of the wise

PreviousNext

Return to G9 / AJS Model 20

Who is online

Users browsing this forum: No registered users and 5 guests