JD tank variations 1925 - 1929

[pfindlay]

Does anyone know (maybe MMasa?) which JD tanks had ribbed inner walls and which had plain? See these two pictures ...
Peter

JD tank 2.jpg

JD tank 1.jpg

[Jerry Wieland]

Experience has taught me that any variations usually are at the beginning or end of a run. The only difference I am aware of is the 1925 tank having 3 wire clips underneath instead of 2 with a removeable one like 1926 and later. Mark is a good source for information. Jerry

[Jerry Wieland]

Well I wrote the above note before I looked at your pictures and I believe the bottom tank with the smooth panel might be a 1925 with the 3 wire clips. Jerry

[camsaure]

Someone correct me if I am wrong, but I thought the 25 tanks had 3 tabs for bolts/ mounting on the bottom instead of two. Also wasn't there a 29 tank with a difference in the valve cutouts?

[MMasa]

Camsaure, you are correct about the 1925 tank. It's 3 MOUNTING TABS and not three wire clips. It may have also been only a partial year thing. Also regarding the 1929 rocker tower cutouts on the right tank; 1929 tanks have a "divot" stamped into the top sides of the cutouts about 1/4" deep. This was to allow for clearance of the grease gun to be attached onto the 1929 only large axle rocker arms.
Back to the original question, I believe that the ribbed tanks appeared sometime in the 1928 model run.
This is antecdotal, and is based on the observation of a few original paint bikes over the years.
Mark Masa

[Jerry Wieland]

My mistake. I knew it was something different and I misspoke when I said wire clips - should have said mounting bolts. Sorry Guys.

Experience has taught me that any variations usually are at the beginning or end of a run. The only difference I am aware of is the 1925 tank having 3 wire clips underneath instead of 2 with a removeable one like 1926 and later. Mark is a good source for information. Jerry

[pfindlay]

... I believe that the ribbed tanks appeared sometime in the 1928 model run.
This is antecdotal, and is based on the observation of a few original paint bikes over the years.
Mark Masa

Thanks, this is very helpful. Peter