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1952 K-model sprocket cover

I snag a correct cover for the K-model. pdf version

The sprocket cover on my K-model engine was chromed. This is not stock, and I detest chromed aluminum. 

It turns out the sprocket cover on the engine was for a 1962 Sportster. I learned that when I found this cover on eBay. I won it with a bid of $189.49. Shipping was $11.35. There were 15 bids.

The seller was a few miles away in Felton, CA. Turns out that I sold him a Joe Hunt Magneto a few months later and got to meet him. Mike is a stand-up guy who restores KR race bikes. So now I have the "correct" sprocket cover and a new friend.

I bought this cover for my 1962 Sportster, so it shows up on the cost table before I bought the K-model.
Date Descript Cost Shipping Total
03/15/12 Sprocket cover $189.49 $11.35 $200.84
03/21/12 Engine, uncrating $2,500.00 $464.56 $2,964.56
03/23/12 Rolling chassis, uncrating $3,500.00 $669.00 $4,169.00
$6,189.49 $1,144.91 $7,334.40
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Here is the lead eBay photo. It comes with the spring stop and the two Zerk grease fittings, and also the clutch worm assembly in the center. There are people on eBay selling just the screw for 10 bucks.


Here is the second eBay photo. The auction title was: "Harley sprocket cover K KH KHK KR XLR XR750"
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This is when you know you are dealing with an honest guy. Mike included a photo of a flaw in the casting.

Here is another honest picture. All the old sprocket covers get chain damage on the inside. Mike showed that.
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When I got the sprocket cover, I set it down next to the one that came with the motor. The flat goes past the center worm and extends on the left side. The 1962 cover is round around the center worm. The Zerk grease fitting for the kickstarter shaft is relocated on the 1962 cover. I assume this is to make it easier to reach and also to remind riders that it is there and needs greasing.
Yes Mike's cover has the spring included. The casting is different around the center worm. The 1962 part on the right has an added dowel pin hole on the bottom. It looks to be a little stronger, with a bit more aluminum. It is a classic engineering mistake to only account for normal or "expected" loads. That would be the spring load of the clutch pushing back on the center worm and the force of a rider jumping on the kick-start shaft bushing.
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But the engineers should have "expected" riders will mis-adjust the clutch, which can break out the center section. It also damages the clutch pressure plate. The other "expected" load is dropping the bike on its right side where the kick-start lever puts a torque on the cover that breaks it in half. This is exacerbated if the chain has carved up the inside of the cover.
A close up of the casting number on the 1962 part that was on the engine. The "A" means they had to do a running change on the 1962 part or maybe this is for an even later year. Don't confuse the casting part number with the finished part number.
Here is the 34874-52 casting number on the eBay cover.
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The correct cover looks better and won't pit or peal or flake like the chromed cover. Turns out the one bolt that came with the motor is also incorrect. The Harley parts book shows the 1952 K-model has straight-slot heads on the two bolts.


Now I have to strip the gearcase cover, or find a replacement that is not chromed. I am resisting taking anything apart. It will be interesting to see if the gearcase is 1952 or later. Harley casts the year into the inside of the cam cover. Bead-blasting the sprocket cover will give it a nice uniform look.
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