Tachometer

[David from Kansas]

Sometime in the past I acquired a tach and cable for a John Deere (??) it looks original and not a replacement. It has a part number on it of AR21664R both on a paper label on the exterior and printed on the face of the tach. The cable measures 20-21" and makes the tach register when turned with a drill. The face of the tach would indicate it was something with a 5 speed tranny. I looks 2-cyl era to me. I tried to ID it in the JD parts site with no luck.
I would like to sell it to someone who can use it. Anyone who can help?? Thanks.

 

[Jim.ME]

When you have a JD part number with a letter on the end try dropping the letter when you search if it doesn't get results with the letter included. I found this ad web searching AR21664. A check of the numerical parts list at the end of the 720 and 730 parts catalog turns up AR 21664 R. Without a number on the cable, it is a guess that it might go with the tach for a 720/730.

PartsASAP Used Tach AR 21664

 

[used red MN]

When you have a JD part number with a letter on the end try dropping the letter when you search if it doesn't get results with the letter included. I found this ad web searching AR21664. A check of the numerical parts list at the end of the 720 and 730 parts catalog turns up AR 21664 R. Without a number on the cable, it is a guess that it might go with the tach for a 720/730.

PartsASAP Used Tach AR 21664

I think somewhat recently a member was inquiring about who could rebuild one of those in that model group.
Found it.
JD 70 tach thread

 

[IAfarmguy]

When you have a JD part number with a letter on the end try dropping the letter when you search if it doesn't get results with the letter included. I found this ad web searching AR21664. A check of the numerical parts list at the end of the 720 and 730 parts catalog turns up AR 21664 R. Without a number on the cable, it is a guess that it might go with the tach for a 720/730.

PartsASAP Used Tach AR 21664

I don’t believe the tach that the OP is talking about could be for a 720/730 because he mentions a five speed trans. While those two tractors had a six speed. I don’t remember the 70 that dad had when I was a kid. Was it a five speed or six speed? And didn’t the 70 tach come as an option that mounted to the side of the governor?

 

[Jim.ME]

I don’t believe the tach that the OP is talking about could be for a 720/730 because he mentions a five speed trans. While those two tractors had a six speed. I don’t remember the 70 that dad had when I was a kid. Was it a five speed or six speed? And didn’t the 70 tach come as an option that mounted to the side of the governor?

I don't have any of those tractors, I only relayed that I found that tach part number (he posted) in that John Deere parts catalog. Could his tach have the wrong part number marked on it? A picture of it would have been good to include.

 

[Fixingfarmer]

None of the bigger row crop 2 cylinders would be 5 speed all 6 speed the 5 speed 2 cylinder list is pretty small

I think the R but with the 80 I think that was improved

420/430??? That’s my guess
Agree a picture of it would be nice and max rpm might give it away as well