Rocker Arms

R65 Head Removal

It’s the middle of November, and the week of Thanksgiving… So naturally, the moment I decide to start tearing my bike apart for it’s major overhaul, it ALSO happens to be like 80 degrees outside. It’s a beautiful day to be on the bike, and I’m dismantling it. Ok enough whining….

I started by dropping the drain plugs on the oil pan and tranny, then removed/drained the tank.

While the fluids drained, I thought I’d go ahead and take a break. Sam Adams style….

This is also a good time to bring up organization. I’ve gone a bit obsessive with my organization practice this time around. Everything labeled in ziplock bags.

Before you can pull the heads, you have to remove the carbs and the exhaust. The carbs are fairly simple. Just disconnect the throttle and choke cables, disconnect fuel lines, and loosen the hose connecting the carb to the head, and voila!

The exhaust… well… you’ll need this ugly scrap of metal. The finned exhaust wrench is available from a number of online BMW parts stores, including Capitol Cycle and San Jose…. Which.. funny story about San Jose… They charged me 25 bucks for UPS 2 day delivery, and then sent it USPS (which cost them 8 bucks) and it got lost. I never use USPS. I am willing to pay more for more reliable package delivery. So thanks, San Jose, for ripping me off.

The exhaust took a little bit of effort to get off due to it’s state of oldness. I also had some emotional support from my best friend Maverik.

I removed the valve cover, just as before in my post about my rocker arm replacement. With the rockers removed, you will now be able to pull the push rods and then wiggle the head off. One note on the rockers.. It’s not a bad idea to keep them together so the bearings don’t slide out. I’m actually unsure if this is really an issue with bearings in good condition, but I didn’t take any chances. I bound the rockers with some wire to keep them happy.

Again, I tagged and bagged every little nut and bolt. It’t turning into a bike in a box.

Be careful pulling the heads off, as you don’t want the pistons banging against the engine case when they slide out of the cylinder. My piston heads had quite a bit of carbon buildup.

A look inside the cylinder reveals some pretty funny cross hatch on the cylinder wall. Almost as though someone attempted to hone it, but suddenly realized they had no clue what they were doing and just stopped. There was also quite a bit of carbon buildup on the area around the valves. This will be sorted out at the machine shop.

I sat the heads aside while I cleaned up my work area. I then cleaned them up to prepare them for the machine shop on Monday.

More to come tomorrow.

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Saturday, November 20th, 2010 BMW Cafe Racer No Comments

Rocker And No-Roll

So friday I developed a bit of a clanky knock on my way to work. I was almost there, so I just took it easy the rest of the way. Something similar cropped up once before. I thought it was my imagination, but I noticed a light pinging, which went away after a bit. I went out at lunch to check on it. Started it up an found it was still knocking quite loud. I weighed my options after work and decided it was probably some spark ping, and that I should be ok for the short ride home as long as I don’t open the throttle up too hard. The knock got louder on the way home. This is when I realized I had a really problem.

My goal with this bike since I got it was to get it in decent shape to ride until the winter, at which point I’d hand it over to a fella named Perry Bushong who is a Jedi Master in the art of taming the Airhead. With his help, I hope to rebuild the motor and get the frame powder-coated, etc….

I finally got around to tearing into the bike today. I hoped it would be as simple as adjusting the valves. Something Airheads are known to enjoy on a regular basis.

To get started, I removed the main valve cover nut.

Next I removed the nuts on the opposite said of the main nuts. These are on the upper forward and lower rear sides of the jug. In retrospect I probably should have reversed this step with the first one.

I gave it a few gentle taps with the rubber mallet to loosen it up.

I gave it a slight tug and a wiggle and it pulled right off.

As the valve cover came off, I noticed some bits of metal falling out. I immediately knew I was looking at some real work ahead of me.

I found these small needles in the valve cover. They look a lot like watch pins. They were also laying inside the valve cover area. I looked around for loose-looking bits. It turned out the one thing I was getting in there to adjust was the thing that was seriously afflicted.

So I set about removing the intake rocker.

Next, I pulled the rocker assembly apart (suspecting the pins I found were in fact the rocker bearings).

Sure enough, what used to be the rocker bearings is now busted up metal.

You can see here, the rocker assembly is pulled apart with all the little needle bearings. I had a look around for new bearings, and most forums suggest they used to be $5 from BMW and now they’re $30. I hope that’s not the case, as this bike takes 8! Two per rocker… two rockers per head. FML.

Lastly I inspected the push rod for damage. Looks to be just fine. I didn’t pull the intake valve, as I plan to be replacing those anyway in the rebuild (if they need it). The valve springs did look good. It could have been a lot worse.

So tomorrow I go on the hunt for new rocker arm bearings. WEEEE!!! Thanks Kate for snapping some photos.

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Sunday, October 10th, 2010 BMW Cafe Racer No Comments

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