Just to give others some photos and ideas, I took a perfectly serviceable starter off an 18 HP Briggs & Stratton opposed twin cylinder tonight to show that the engine and flywheel do not have to be removed.
In this photo, one can see that I was originally using lock washers for shims. The lock washers measure .075 thousands.
Note the difference between the two gears. The one on the left had the .075 washers shimming the starter forward. The gear on the right didn’t have any shims and was installed like it was from the factory. The gear on the left has well over 100 starts on it, while the gear on the right only has about 50. Since shimming the gears, they really do last a lot longer. Additionally, the shiny portion of the gear that you're seeing is actually the coast side. I know it looks like the drive side, but the gears are facing the wrong way and are upside down. I can only assume that the flywheel's wearing it as the gear disengages the flywheel. Hey, I'm no master mechanic be sure...
I used an old steel door hinge because I couldn’t find a decent piece of aluminum. It did work nonetheless. The shim I made was .0875 inches thick. Here are photos of my template. I’m still unsure if I’m going to make a new shim that’s .125 inches thick or not. I’ll have to poke with it some more. Here are photos of my template.
Once the bolts are out, the starter simply twists out as long as the wires are cleared out of the way.
After changing the gear, insert the inboard bolt into the starter and slide the entire unit back into place. *Note, one can see the bolt’s really there.
I tried a new method tonight. After jamming the inboard bolt home with a screw driver, I didn’t start the outboard bolt. I simply kept prying with the screwdriver as I turned the bolt with a ½ inch open end wrench. It started right away. I tried this method several times, which is new to me as I used to start the outboard bolt first. Each time I tried it this new way, the bolt started right away. It’s rather simple actually.
Once the inboard bolt’s turned in as far as it can go, but still leave room for the shim, I pop in the shim, and start the outboard bolt.
The above set up works far better than messing with washers… It knocked off considerable time because I didn’t play drop the washer, take out starter, and do it all over again for thirty minutes. It was rather simple with the new shim. It still takes about 10 – 15 minutes due to the rear bolt being so time consuming.
I could probably get away with 1/32 – 1/16 additional shimming. In the next photo, I jogged the starter until the gear stayed engaged with the flywheel. I know it’s blurry, but one can see that the gear’s not completely engaging the flywheel. As I’ve stated previously, I’m not sure if I’m going to mess with this set up anymore. I’m currently using the cheap imported gears from Taiwan, and I’m quite impressed with how long they’ve held up. With the shim, the gear’s already lasted for a week's worth of daily use cutting firewood, burning yard waste, and hauling dirt, so this means that the tractor’s started at least 30 times a day. With use like that and no shim, the gears have to be replaced every other day, or at least that’s been my experience. I have to stress this again and again, do not buy the cheap Taiwan gears if you can avoid them. Get the OEM gears from Briggs & Stratton. They're still made in America, and they're considerably more durable! The Taiwan gears I'm using are Stens. It's what the local guy working out of his home's garage carries, so in a pinch that's what I use. Next time I'm simply ordering ten of the OEM Briggs & Stratton gears. They're definitely worth it.
Other thoughts, problems, and things that I've run into:
When changing this style starter, I run across this every so often.
Yes, that’s the bolt I dropped down into the cooling shroud, and wouldn’t you know it that little bugger’s out of my reach! I simply tape old speaker magnets from junk cheap speakers to a stick. In this application, I used an old twisty shaft from a junked stationary bicycle’s speedometer and fished it right out.
I’m supposed to be putting together a sticky thread on this procedure. I hope to be able to get a hold of the new style starter gear return that looks like this. *Note how the spring’s much larger and goes on the outside of the white worm gear looking thing.
The old style has never satisfied me on its ability to proper return the gear after the engine’s been started. *Note how small the spring is and its location.
I’m going to see if I can fit the new style set up on the old type starter. I have a junk starter that volunteered to be my guinea pig.
I’ll keep you posted. This is bolillo_loco reporting from underground radio free Pennsylvania on pirate satellite