Install oil pressure gauge

[Gary Sweat]

I had an oil pressure gauge on my YM1900 until the nylon line broke. At the time I did not know there was a copper line kit available for it. When the line broke I decided to put a new oil light sending unit back in and just use the light as I had read some don't think it is worth taking the chance of getting ripped off on limbs.

However the brand new sending unit I just got in is DOA and the light stays on, so now I want to go back to the gauge. The gauge line end did not fit very well in the threaded hole in the block but it held. I was never happy with it but could not find the right adapter.

I think Yanmar uses the BSPTT but not sure. Does anyone know where I can find an adapter for the Yanmar threads to standard NPT?

 

[winston1]

Gary, from my reading it would seem the Yanmar threads may be 1/8" bpt, if that is so here is and adapter. Might do a little measuring and compare with the attached dimensions. McMaster-Carr

 

[Gary Sweat]

Gary, from my reading it would seem the Yanmar threads may be 1/8" bpt, if that is so here is and adapter. Might do a little measuring and compare with the attached dimensions. McMaster-Carr

Thanks, that looks to be the one I need. I'm pretty sure the pressure switch is bad. I took it out and cranked the engine and oil gushed out of the hole. I want to put the gauge back in just to make sure. This time I'm putting in the copper line. The nylon lasted about 2 years but the weather got to it I guess.

 

[reb]

When I put the gauges on my 1500D I found the oil pressure adapter in a set of metric adapters from the local auto parts store.

The copper line is a good idea. I used the same piece I bought about 42 years ago. It has served in 5 or 6 vehicles now.

 

[Gary Sweat]

When I put the gauges on my 1500D I found the oil pressure adapter in a set of metric adapters from the local auto parts store.

The copper line is a good idea. I used the same piece I bought about 42 years ago. It has served in 5 or 6 vehicles now.

Well, I just got back from the auto parts store getting a new gauge and to my surprise it has the adapter plug in it that I needed I went with the electrical set up this time. Hope I don't have any issues with the sending unit. The gauge has a second tab that you can hook the warning light up to so I can have both. The sender is rather bulky but with the adapter it should be out far enough to screw in without hitting the frame.

 

[California]

Gary, when I replaced my oil pressure sender I discovered that US and British pipe thread standards are similar. Apparently the pipe diameter and threads per inch are the same but BSPT has greater taper toward the nose of the sender. So a Japanese/BSPT sender will always thread into the smaller BSPT hole in the Yanmar block, but some USPT fittings are large enough at the nose that you can't catch the first thread.

I went through all this and tried the various combinations a couple of years ago. I posted my results in this (longwinded!) thread about replacing my oil pressure sender. I found that my various brass fittings weren't distorted after threading them in securely in the Yanmar block, and my experiments didn't hurt the block. But about half the fittings in my (US) brass fittings collection were too large at the tip to catch the first thread.

My point here is that you might try a USPT brass 'street elbow' (M to F threads) and aim that sender upward instead of sticking it straight out where it can snag on brush.

 

[jonyyuma]

You might prefer that it is 90 degrees up, so it can drain after you turn off the engine.Ya know, not accumulate any sediment in it from cycling.Jy.

 

[Gary Sweat]

Well, here is how I wound up mounting it. Mostly because it tightened up at that angle and also because I would have to relocate the wiring. The photo doesn't show it but the sender is at the same level as the steering rod. Now that the loader is on there is a lot of steel in the way of limbs and such so hopefully it won't snag the wires. If it does then I'll have to come up with a shield around it.

 

[jonyyuma]

At least the bulb is not turned down.It should slide by the limbs? Why is the loader always in the way?? Bending over the arms can be a chore? At least for me. Jy.

 

[winston1]

One thread per inch difference on npt verses bpt. McMaster-Carr