Oil Light on

flyerdan · Jul 31, 2016

One thing to watch out for when shopping for replacement senders is threads. Datsun (and Nissan) uses BSP threads on their sender units, a holdover from colonialism. It looks similar to 1/8" NPT, but there are a lot of posts on the Datsun forums about the bad things that can happen when it's overlooked. It's not inconceivable that Japanese manufactured tractors might share the same trait, especially if the manufacturing facility has been around since the 50's-60's.

California · Jul 31, 2016

I wouldn't try threading NPT iron threads into a Yanmar block. But I experimented with several brass NPT fittings I had in the barn, I think they are old gas lighting plumbing and certainly not BSP or metric. Some were too large diameter at the first thread to start threading, others threaded in a few turns by hand and then I wrench-tightened them. None came out distorted after this experiment. And the block wasn't hurt by this - the Japanese (BSP) sender I ultimately installed threaded in easily and sealed as it was intended to do.

Are those Datsun-forum owners talking about threading iron NPT into an aluminum front cover or something? I can see how that could strip threads.

Looks like Hoye sells the same sender for little (YM 1100) and larger (YM2000) models. They also offer an adapter to put NPT gauges etc into 'Yanmar' threads.

flyerdan · Jul 31, 2016

Here's a thread on the differences between BSP and NPT. I think the major problems in the Ratsun community is threading in a junkyard GM sender until it breaks off, and the problems getting it out, especially with hammer mechanics who aren't as skilled with some of the finesse required for such situations.

shovelrider · Aug 7, 2016

changed oil(sae-30w for diesel), replaced filter(wix-51334, and put ImportedParts #18-1568(O'reillys) oil sending unit in. No problems w/the oil sending unit thread wise. Light is off and runs like it should, will add 'T' and gauge w/copper tubing ltr. this week. Thanks to all for info. Jim