1938 Chief crank case breather

[39ChiefBonnie]

Any experts on 38 Chiefs out there. Does anyone have any information on the breather line the exists the LHS crank case and runs up to the oil tank? I have been told that early Chiefs has this breather line and at some point before the 39 model it was discontinued - a running change. Refer images. Appreciate any feedback.

[tfburke3]

Hatfields resto guide references this in note 86 and section 3.3 crankcase breather systems.
Basically early 38 had it,possible running change either plugged hole or hole not drilled for later.
In 3.3 he gives before march 17 as early but then uses ccf-101 as cut off which is obviously mistake.
Cant tell by your numbers if late or early.
No mention of the oil tank hole,plugged or gone if no breather.
If you got a hole in the tank and the case I would run it .
I have Iron Horse tanks for my 38 and unfortunately they came without the oil tank hole so I have to run a plug.
Tom

[Oldchief]

I have a very early Sport Scout, one of the first 80 bikes made that year and mine does have the breather on the LHS of the crankcase. I agree that early 38's had this on the Chief also. I know that the first bike made for 1938 was a Junior Scout. I have a picture of the motor somewhere, but Junior Scouts did not have the breather on the LHS as it would interfere with the motor mount. Indian was notorious for making running changes during a model year, so it is very likely that the hole was not drilled on later numbered bikes.

[39ChiefBonnie]

Thank you Tom,

Your response has led me to the information I was chasing. Appreciate it.

Found that Service Shot No.79 (not dated) issued on or after January 21 1938 but before March 17 1938, details the changes to the Oil Pump Breather and Cam Case Breather for early and late chiefs.

The Breather Tube Elbow (FN 38990) which exists the LHS crack case accepts the oil tank vent line (and is not a crank case breather as I initially thought it was). Hatfield quotes a reference in the October 1938 Motorcyclist showing the oil tank vent was unchanged as at that date.