1927 Big Chief

[C.Flint]

Hey friends, I am looking for a photo to help return a generator to a 1927 Indian Big Chief. If someone could take a picture of the crankcase like the one attached, I would be grateful.983A87D2-943E-47E4-831F-F04ABBABCB84.jpeg

[FLFD7]

Are you missing the strap that clamps the generator in place? I have a 1925 Chief and figure it mounts the same way….

C226A8E0-A31D-4B14-900D-E4B4D1C1794D.jpegAFF079D5-C580-45BE-B4F5-D9B3D066C8C1.jpeg

I can’t see the “shelf” your magneto mounts to in your picture, but it should have a “hook” on the front that the strap grabs onto, and there should be a stud in that threaded hole on the front of the case that the strap tightens with.

I hope the pictures help, at least you get an idea of what the strap looks like.

[C.Flint]

Thanks FLFD7…appreciate the rapid response. I have the strap, I am trying to understand if the case was modified at some point. The “collar” spaces the generator at what appears to be the right distance for the gear to engage appropriately. The parts manual describes a felt seal which must sit inside the collar (around the generator shaft). It appears that I can fit an oil seal in that space. The pictures are a great help.

[gharper]

Yes, your case has been modified.... I don't have any pictures of an original case, they are often damaged. Originally all 22-31 Chiefs had the same setup. There was a small steel ring pressed onto the outside of an aluminum boss on the back of the case. It was pressed on and pinned. It also had a left hand thread. There was a very thin nut that threaded onto this sleeve which sandwiched a small felt ring in place. The design was to work like a faucet washer packing nut, tighten the nut a bit and it squeezes the felt down around the shaft making a seal, of sorts. Often the boss is ripped off because it is a left hand thread and gets forced the wrong way so the nut and boss get discarded. Not the best arrangement anyway. On both my 24 and 31 Chiefs I bored the case out to accept a lip seal for both the generator shaft and magneto gear, makes for a very tight setup, they don't leak at all! The original felt seals on both mag and generator didn't work well and the thing was a leaky mess.

Looks to me like someone welded on a ring to the back of the case which could hold a lip seal. Measure the hole and generator shaft and see what works. One word of caution on the generator shaft though..... The Chief used the DU5-H generator which had an extra long drive shaft to reach into the timing chest and line up with the gears. It also had a curvet flute cut into the shaft which was used to pull oil back into the engine case. If you put a seal in the boss and want it to run on the shaft, it may be running on that flute, so it needs to be covered. I've slipped a piece of brass tubing over the shaft and held it in place with loctite. This will give a .50" OD shaft for the seal. The original generator shaft is under .50" diameter. I may have had to turn the generator shaft down slightly to accept the tubing, but that makes a nice smooth surface for the seal.

Below are a coupe pictures of the 31 cases after machining. Note the generator hole is BIG. I did this to accept the same size seal as the mag, 1 1/2" OD and 1"ID I believe. I put a 1" OD steel sleeve on the generator shaft which made the sealing surface. The beauty here is the generator can be removed without taking the plug out of the front of the timing cover and removing the gear, simply loosen the strap and out it comes, gear attached, much easier! In your case, you won't be able to do that unless you tear the motor down and do some serious machine work.

Regarding the strap, it fits under the magneto and is held in place with 4 screws. You will need to remove the mag to install it. There is a stud threaded into the case at the bottom of the strap. A nut and lock washer squeeze the strap onto the generator. I've found I need to put a bit of thick gasket paper between the generator and strap to keep it tight.

Also, if you plan to ride much, consider a voltage regulator for the generator. I make them for Splitdorf generators. Here is a link to my web site, also have lots of good info there on rebuilding Splitdorf generators. Sorry, no Autolite regulators available any longer...
www.splitdorfreg.com

Chief generator and mag seals 1.JPGChief generator and mag seals 2.JPG

[C.Flint]

Thanks Gene. This helps a lot. The alloy collar on mine has been pinned and sealed in place. The height of the collar is such that the DU5-H shaft is just the right distance for proper gear engagement. I can fit a lipped oil seal in the collar with 3/4” OD and 1/2” ID. My strap has two countersunk screws that hold the top (under the magneto) and I have placed a stud for the low attachment point. Generator is now snug. I did have to relieve the magneto mounting bolt heads a few thou just to get the generator to fit. BTW, I have one of the 12V alternator/generator units with solid state regulator built in the cap purchased from Crazy Horse Indian (Australia). I have one of your regulators in my ‘28 Henderson…works great!