1985 Magna V30 (VF500C) Engine Rebuild - Clean and Measure

Magna 500 Parts Washer Compressor Rods and Reel

Tools we use a lot when rebuilding the engine. The parts washer has seen the rebuild of three engines already (two and a half really - the 700 only had the transmission rebuilt). Now in the midst of its fourth. The compressor is a must have and the hose reel has a 30 foot range. The pistons and rods look to be in pretty good shape.

Magna 500 Engine Rebuild

The big picture. From left to right in the picture, parts washer, connecting rods and pistons 1 - 4, transmission countershaft and gearing, engine crankcase (block) halves and crankshaft, and how could you rebuild the engine without the manual? This is the first step toward rebuilding the powerplant. Nick did most of the tear down and parts cleaning so far, but I think it's starting to be too much like work for him. I can't blame him since getting his permit is so far off.

Magna 500 Darth Squad

The 'Darth Squad' oversees ALL activity. We run a tight shop here. Darth doubles as a parts caddy. Wolverine ensures the stereo plays only the best rock and roll. None of that country stuff please. Note the infantryman poised to teach a lesson if one gets out of line.

Magna 500 Pistons and Rods

The pistons, piston pins, piston rings and conecting rods have all been cleaned and measured. We record the measurements in a rebuild record for the engine. Since the original block had a crack in #2 cylinder, we've substituted a used block from eBay. Was it sheer luck that it had the same markings as the original? The markings denote the crankshaft journal size, and being the same, we can re-use the original bearing inserts. Or rather could, if the bearings didn't look like they had been oil starved. Guess they're called idiot lights for a reason.

Magna 500 Trnasmission Countershaft View

To the left is the transmission countershaft, gear set, and oil seal, just waiting to be measured. The countershaft bearing is permanently installed on these. Good thing the bearing is still in good shape, otherwise we would need an entire new countershaft. The mainshaft and gear set have yet to be cleaned.

Magna 500 Crankcase Halves

To the right is the replacement crankcase with the original crankshaft, minus gears. The before pictures show the front engine head removed from the engine as part of the diagnosis. The symptoms? Water added to the radiator pours from the muffler joints and the coolant level pulsates with the engine running. It didn't take long to realize it was a blown head gasket. After removing the front exhaust pipes, it was obvious #2 cylinder was the culprit. The water poured in the radiator just poured right out the exhaust port. It wasn't until the head was removed that we realized the block was cracked as well.

Magna 500 Parts and Stuff

The rest of the parts are just waiting their turn in the 'staging' area. The first parts to come off were the exhaust system, running gear, side covers, chain and guard, fuel tank and seat. Nick degreased most as they came off the frame. They still need cleaned and polished, but AFTER the engine is running. After we disconnected the electrical and drained the oil, the engine was removed and then the rear head. Once the engine covers were removed, the clutch came off, then the starter clutch. The alternator (flywheel) presented a challenge, the flywheel removal tool I had for the other Magnas was too big for this one. Not wanting to wait on a tool to be ordered and shipped, I used a brass drift and the plastic hammer to 'knock' it loose. All that was left was to split the cases, which we did as seen in the picture above.

Running Magnas Stable

The rest of the 'staging' area holds the other (running) members of the stable. Well, the 1100 is almost running, still having a slight problem with the carburetor float height. In the foreground is Ann's twin cylinder Shadow 500. As you can see compared to the before pictures, I've already made some improvements, like the new seat and cover, toolbox and the top grab rail. The tank and fender still need paint and everything else still needs polished. The mini turn signals have got to go. I have the OEM originals, and just ordered some rear stems. Unfortunately, they discontinued the rear stems for the Magna 500, but at least new oil seals and a fork brace are on the way.

Magna 500 Rebuilt Transmission

Here's the transmission all clean, measured, rebuilt and installed. The shift mechanism is a real Rube Goldberg though and more complex than the other Magnas. Instead of using an arm to push or pull on pins in the gearshift drum, it uses a planetary gearset to rotate a gear with pawls that engage the gearshift drum, and plates and pins and a bunch of other extra nonsense.

Magna 500 Honed Cylinder #1

Here's the engine cylinder #1 after honing. I started out using one with honing stones to remove the rust from the cylinder walls. I followed this up with a ball hone to put the crosshatch pattern in the cylinder walls which will help seat the rings and hold oil on the cylinder wall between strokes. The angle is important, too shallow and too much oil stays on the cylinder walls increasing oil consumption, too steep and the oil runs off the walls and lubrication is inadequate.

Magna 500 Cleaned Up Rear Fender

Waiting to work on the Shadow 500 fuel tank, I decided to clean the Magna 500 rear fender. I was tired of picking it up to move it only to get all dirty from handling it. First I removed the seat lock, then unbolted and separated the upper and lower fender parts. With those apart, I removed the license plate holder and light from the lower fender and the tail light from the upper fender. Then each was scrubbed with a toothbrush, degreaser and soap. The lower fender was badly sun faded so I soaked it in Armor All and let it sit overnight. The end result can be seen in this picture. Not mint, but as close as it gets.

Magna 500 Crankcase Halves Mated

Here's the engine crankcase halves mated with the heads loosely installed ready to measure the cam oil clearances with plastigage. After cleaning and comparing the original and replacement cam chain guides, I installed the originals which were in better shape. At first I thought the originals were deeply worn and grooved, but realized after looking at the nearly smooth replacements, they were shaped that way on purpose. Oh well, not the end of the world, but after cleaning the heads I saw something that gave me pause.

Magna 500 Useless Destroyed Rocker Arms

Unfortunately, when Nick took the heads off a while back, I didn't look at them very closely. I should have. Six of the eight rocker arms are totally destroyed, faces concave where they should be convex. Now I know what was causing that loud 'ticking' when we first bought this bike. Just great. New rocker arms from Honda are $46.15 each if they even have them. Times six and that's $276.90! I already have nearly $1400 in this bike and now am looking at $300 more in parts. That's about all this bike will bring restored to sell it outright.

Magna 500 Flattened Camshafts

Looking next at the camshafts, I see flat spots on the lobes caused by the wear against the destroyed rocker arm faces. Thankfully the lobe heights are still within the service limits, but I have to wonder what effect the flats will have on replacement rocker arms. It can't be good. If it still makes that ticking sound, I'll know they need ground or replaced. I'm hoping it won't be as pronounced as it was when we bought it.

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Last Updated: 11 Jan 2018