I have been working on a tractor for our local Lions Club viewtopic.php?f=1&t=76172
I have discovered something odd. This cub has a block with part number 251341R1 date code 2-25-R. This cub uses the same valves as others, along with the same keepers and spring seats, but standard valve springs will not fit. They are too long, and the keepers cannot be installed. I compared tall the parts with some I had on the shelf, including measuring the springs when fully compressed, and the new springs along with a set of old ones I had on the shelf are .3 inches longer than the ones in the cub.
Doing some looking around in the shed I checked and I had a block with the same part number 251341R1 date cod 11-26-Q on the shelf that was originally in my loader club, and when I started checking the valve springs I discovered they were also shorter than normal. After doing some checking I also found that standard springs would not fit it. The ones in both of these blocks measured .646 to .656 fully compressed, and the ones I found laying on the shelf and the new ones measured ,878 and .967 fully compressed. I wonder if this is also the length of the springs used with Rotocaps, but have never seen a Rotocap, much less have a spring to measure. I was curious if anyone else has run into this problem.
As a matter of coincidence, both of these blocks had the right ear broken completely off.