Removing the Carburetor and Pulling the Rear Cylinder

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My friend Steve was in town for the weekend, so we naturally decided to dive into the little hot rod and make some progress while we waited for the new parts (which should be here next week). Having spent some time as a motorcycle mechanic when he was younger, it was nice to have someone here with a little more experience than I have doing this sort of thing. And, it was nice to have the company—I'm usually doing this stuff alone in the garage.

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The logical place to start was to remove the carburetor. I removed the breather bolts first (which I forgot to take a picture of). To remove the carburetor body, there are two set screws you reach from the back side of the carburetor. Once those fasteners are off, the carb is free from the manifold.

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With the carb free, you next need to disconnect the throttle cables from the carb. To do this, I needed to loosen the cable at the throttle to give it a little play so we could fish the round cable ends out of the housing. You do this by loosening the double nut on the throttle cable at the throttle. This is one of the many times Steve, having done this before, gave me a leg-up on figuring out the easy way to do it. The cables were then pushed through the frame and left to drape free in front of the handle bars.

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The fasteners that connect the manifold to the heads don't have a lot of clearance, so there's no way your going to get a standard wrench in there. I didn't know what I would need so I purchased the Yost Performance Intake Manifold Tool and Kastar 5530 Manifold Wrench because they weren't too expensive and I didn't know which tool would work the best. As it turned out, we used both of them. There was less clearance on the front of the manifold, so the Yost tool worked best there. Steve was able to use the Kastar tool on the back side while I loosened up the front.

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Looking at the inside of the manifold, you can see the ridge left where the opening on the casting was originally machined. I'll probably port match with a diamond burr to reduce turbulence and hopefully gain a horsepower or two before I put all this back together.

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After we took the carburetor off, we started on the rocker covers. There are four set screws on the top of the covers which once removed make it easy to lift them off. The cover is actually in two pieces, but they pulled off together. Both pieces have gaskets that will need to be replaced when it goes back together.

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Before removing the cylinder heads, you need to make sure the crankshaft is in top dead center on the compression stoke. With a small probe gently inserted into the spark plug hole, you can feel the piston rise and fall as you rotate the rear tire (shift into 5th gear to make this easier). Watch the rear rocker go down and then wait for the piston to be at the top of the stroke. At this point, you're at top dead center of the compression stroke.

To remove the heads, there are three fasteners plus the four fasteners on the rocker arms. The shop guide instructs you to start with the three fasteners that aren't on the rocker arms and once those are loose, proceed to the bolts on the rocker arms that are directly over the pushrods. The rear fastener on the right side won't slip out until you loosen the entire assembly and the rocker cover is free from under the frame.

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The rocker assembly required a little tap with a rubber mallet in order to lift it off. As the assembly moved off the head, you can pull that last bolt all the way out.

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With the rockerbox assembly off, you can see the valve springs and the pushrods. 

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Before removing the head, I pulled and inspected the push rods to make sure they were in good shape. You can see the rear pushrod has three red stripes on it to make it easier to put them back in the proper order. I've been bagging and labeling the small parts as we go—this included the pushrods so I can make sure to put them back with the correct cylinder.

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Removing the four head retaining bolts required a little bit of a persuader to loosen them up, they were pretty stubborn (particularly the fasteners on the left side—probably because they see more of the elements. You'll need a 16-point socket for these fasteners (and likely a breaker bar to get them started).

There is a specific order you need to remove these bolts otherwise distortion of the  head, cylinder, and crankcase studs can result if you don't do this gradually and in the proper order. That order will be outlined in your shop manual. Although I haven't removed the front cylinder yet, I noticed the pattern for removing those bolts is different than the rear.

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Once the four head retaining bolts are removed, you can lift the head off the cylinder. I was a little surprised at how easily it slipped off. I don't know why, but I was expecting it to be a little more difficult than what it was.

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When I pulled the head off, the pushrod covers also pulled up, so we pulled them off and set them aside. Be aware that there are o-rings in the head where the pushrod covers are inserted. You can also see where the bottom of the pushrod covers seat and the pushrods sit on the tappets.

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With the head removed, you can see the piston and can now slide the cylinder up and off. Having never done this before, for some reason I thought this would also need a little more coaxing than it did.

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We wiped out the cylinder and inspected it to see if there was any obvious damage. I was a little concerned there might be with the shavings I found in the crankcase, but it looked good. There didn't appear to be anything other than normal wear.

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Before removing the retaining pins for the piston wrist pin, I packed a rag around the crank in case one of the pins flipped off and dropped into the engine. I didn't want to split the cases to find a pin I'd dropped down there.

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With the cylinder removed, it was time to wrap it up for the afternoon. It was a great couple of hours and wasn't as difficult as I had expected. We tried to be very methodical and bagged and categorized all the parts and fasteners as we disassembled the rear head. In instances where some of the fasteners were longer than others, we labeled them with tape so I wouldn't have to rely on my memory when re-assembling the top end with the new cylinders and pistons.

This is probably the biggest project I've undertaken on the bike, but was really a lot of fun.