Chrysler/West Bend/etc recoil starter pinions

[amuller]

Still playing around with this subject trying to figure out if making some of the 11 tooth pinions could make sense, or if there is another approach.

The flywheel matching the 11 tooth pinion has 56 ring gear teeth. Going just from pics, it appears that the flywheel matching the 13 tooth pinion has 59 teeth. it appears that the 13 tooth pinion was beefed up and has more wall thickness in the upper part. Has anyone looked at the totality of changes made to the starter setup?

I am still thinking that a durable 11 tooth pinion could be made of aluminum bar or possibly a high-strength reinforced resin material. I’m not much of a machinist but may try it.

[jerry-ahrens]

Keep us posted on the starter pinions! I have one of the 12 Elgins with the weak plastic version…. Mine is still intact, but I’m almost afraid to pull the rope with the spark plugs in. Getting this engine running is on my winter to do list. Let us know what you come up with.

[amuller]

OK, I’ve been piddling around with this and have some thoughts to share:

The pinion type recoil starter used by OMC on 5-8 hp units is so similar that it must be licensed or a direct copy. Could be that the OMC 13 tooth pinions could be used on Chrysler, etc, motors. The ID (bore) seems larger but the spindle is not larger. A very loose fit seems part of the design.

Patent US 2938511 A, filed 1955, published 1960, gives a good description of the thinking behind the original design. https://www.google.com/patents/US2938511

Appears to me that when the change was made from the 11 tooth pinion to the 13 tooth pinion (when?), the pitch of the teeth was not changed, nor was the flywheel changed. Rather, the center-to-center distance of the starter spindle to the crank was increased by about 0.141" to make room for a more robust pinion hub, and the two teeth were added to maintain the same pitch while increasing the diameter. If this is so–I haven’t yet examined enough machines to confirm it–it should be possible to use the 13 tooth pinion on 11 tooth machines by shimming the starter spindle out about 9/64in (0.141).

On the 11 tooth motors I’ve looked at (a 1957 and a 1961) the starter spindle brackets are integral with the intake manifold, so moving the spindle outward would require 2 crescent shaped shims, plus 4 flat shims under the bearing caps. These crescent shaped shims would be easy enough to make on a lathe, but since all the loads are outward–away from the crank–epoxy putty might serve as well.

It appears there are at least two 13 tooth pinions available from Mercury:

F525674 (etc) is usually black and has a flange extending out from the major diameter of the pinion teeth. this one seems to have been used on smaller motors. (https://www.amazon.com/F525674-Chrysler … B015NJ6VLO)

803624 (etc) is usually white and lacks the flange. (http://www.boatsportandtackle.com/start … and-15-hp/)

I have no feel for which of these would be most desirable. I am sure there are people here who know a lot more than I do about this.

Any feedback appreciated.

[lotec]

My findings are the 13-tooth was used on the 5.5hp, 7.5hp and some of the 12hp motors. The 11-tooth was used on some of the 12hp and the 16hp, 18hp and 20hp motors. I’ve owned 12hp motors with each and don’t note any logic to the dates where it was used, it seems to periodically pop up on them 😉 from 1955 through 1960.

I always assumed the flywheel was different and think I once tried swapping the 11 with a 13 and it didn’t work. That the mount is different I hadn’t considered. When I have a minute I’ll go count the teeth on the flywheels and verify they are the same number.

I’ve also never tried the OMC 6hp bendix on the West Bends/Elgins and find your comments interesting. Will need to take a look if they could swap.

[amuller]

From what I have to measure/count: ’57 Elgin 12 hp, 11 tooth, 58 teeth; ’61 West Bend 12 hp, 11 tooth, same; ’85 OMC 6 hp, 58 teeth, same diameter. I don’t have any 13 tooth motors to look at, but I counted the teeth on a couple of for-sale images of Chrysler flywheels and came up with 58 teeth, but don’t consider that reliable.

There would be a sort of logic in using the smaller pinion on the larger motors as the mechanical advantage would be slightly greater?

[amuller]

In an earlier post I ventured the thought that the OMC starter pinions (318447) might substitute for the West Bend/Chrysler/etc 13 tooth pinions.

Yesterday I picked up a nice 7.5 hp 1958 Elgin. (These appear to be the same frame size as the 12 hps.) It had an OMC starter pinion on it and the starter mounts had apparently been cut and welded to move the starter spindle out to make room for the larger pinion. I’m hesitant about welding on this part as the reeds are mounted on it. Hopefully precautions were taken. But the basic idea clearly works and was not-invented-by-me.

I don’t know whether the OMC pinions are stronger than the Chrysler ones (F525674, etc.)

[dave-bernard]

I have a 11 tooth chrysler west bend gear if needed. it is NOS. I think it is 11 I will check if you need.

[dave-bernard]

Just dug it out it is a 13 tooth not an 11

[billyzz]

You guys are the greatest!
I’m going to try this very soon!
Thank tou

[seakaye12]

There was a young man at the Tomahawk meet who had an Elgin 12 on display….fitted with a 3D printed starter pinion. It looked mighty nice and it will be interesting to see if it holds up. His name was Ryan and if you see this Ryan….feel free to let us know how to contact you. You can use the Private Message function here so your contact information would not be in a public forum.

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