Oil pressure guage

[Lcarter114 4]

I have a 1986 417a with a Kohler series II engine.  I bought it 9 years ago and the oil pressure light has always blinked.  I replaced the switch and it still blinks.  Has anyone added and oil pressure guage?  Would I just use the same port for thr pressure switch and if so what is the thread size (if I remember correctly it is and odd size)?  What kind of pressure should it have?  Any information would be appreciated.

Thank You

[WHX?? 50,869]

I have added pressure gauges on a few tractors that are pressure lubed. Most with a oil filter have plugged pressure tap at the filter housing. 

1/8" NPT thread and compression fittings with 1/8" aluminum tubing.

 On a series ll it might be the same. Not sure since it doesn't have a filter and I have always been cursed with series 1s.  

I would guess just take off what pressure sensor there is and install the fitting. 

https://shop.advanceautoparts.com/p/american-grease-stick-co.-brass-compression-connector-1-8-tube-male-1-8-27-npt-cf-10c/11408152-p?product_channel=local&store=7177&adtype=pla&product_channel=local&store_code=7177&&&&&gad_source=1&gad_campaignid=16404424262&gbraid=0AAAAAD05GhXQ5lOHT_9dfvGCTdgEWSEqv&gclid=CjwKCAjwq7fABhB2EiwAwk-YbGdYaozGhWkBfVzW2ZuyJkpy6AW44RDeadAiKXnk7WPwypX-1d1QsRoCRxsQAvD_BwE&gclsrc=aw.ds

Edited April 27 by WHX??

[pfrederi 18,384]

[nylyon-(Admin) 7,564]

I didn’t check the wiring diagram for a 417, but with my 416 the pressure switch does 2 things.  First when no pressure it sends a ground signal to the indicator lights which blinks the oil pressure light.  When there is pressure, it sends a ground signal to the hour meter so on my 416, if I removed the switch I would expect the hour meter to stop as well. Diagram for the 416:
 

[nylyon-(Admin) 7,564]

I pulled up a 417 diagram and the hour meter just runs when the key is on and there is power to the Accessory terminal from the key.  It doesn’t say what triggers the oil light but it is either ground or lack of ground from the switch, since there is only one wire from the switch to the panel.  Might make sense to test continuity to ground of the switch terminal with the engine off and on, and check if the do blue wire has any opens to the indicator panel:

 

 

[WHX?? 50,869]

1/16 pipe plug?? Gotta be a typo?? Never heard of such an animal. 

[squonk 42,789]

13 minutes ago, WHX?? said:

1/16 pipe plug?? Gotta be a typo?? Never heard of such an animal. 

https://www.asmc.net/1-16-27-nptf-thread-socket-pipe-plug-dry-seal-3-4-taper-stainless-steel-18-8/

[Lcarter114 4]

Great information guys, I appreciate it.  The 1/16th sounds right.  If I remember correctly when I bought the pressure sensor the threads were different.

[WHX?? 50,869]

Learned something today Squonky 

[kpinnc 13,901]

I used a T junction at the oil pressure switch on a Vanguard engine to do the same thing. You don't loose the switch function but you gain another port to read the pressure. My guage is straight wired to the ignition switch so it operated independently. 

 

And it most definitely is nice to see how many pounds of pressure your engine maintains. My Vanguard 23hp holds 40-60lbs no matter the throttle setting. 

 

 

 

 

[bds1984 1,469]

Back in 2020 I added an oil filter and pressure gauge on a C175 that had a series II engine.  Here is that thread.  Keep in mind, some Series II and Magnums didn't have either filter or pressure port, but if they do, you can easily add either or both.