Monday, June 30, 2014

Motorcycle for sale

Yesterday marks the second time that I have come in from the garagenous zone with thoughts to sell the cafe racer project. At times, my dad was a tool thrower. I am not. I curse at times but I don't generally do that in the garage when things aren't going well. I just do it cuz it's funny. Yesterday even I was alarmed at what was coming out of my mouth while I paced around. Heather didn't say a word. I probably wasn't quite back from the beach yet to be dicking around with the bike but...I did. 

I decided to order an electronic ignition for the motor and ditch the old style points/condensors. Before I order the kit I wanted to pull the carbs back off and take them apart again. When I rebuilt them I used aftermarket main jets and needles and this has bothered me ever since. I still had the stock brass so I wanted to swap them out. In a fit of sheer stupidity, I broke the part pictured below. As soon as I realized what I had done, the expletives flowed. I couldn't even believe what I had just done. 

You are looking at a plate (called a stay plate) that all 4 carbs attach to. There are 4 pieces that attach to the rod that you see sticking through that cracked ear. It's job is to keep all 4 carbs working in sync with each other so that all 4 cylinders have the same air to fuel ratio. You can see the ear cracked all the way through and so did the bronze bushing inside. Done.

The rod gets inserted in the near side ear in this pic, goes through the piece by my thumb, then through the throttle return spring assembly (not pictured), through the other ear and, finally, through the piece by my finger. Additionally, there is a pin through the far side ear that keeps the rod from moving laterally.

Here you see the cracked ear and bushing, as well as the broken pin.

There's also two metal woodruff keys that help keep the rod in place.

This is what the stay plate looks like once all the carbs all pulled off it. So what started off as an easy job turned into an absolute nightmare. I wasn't sure how I was going to get out of this mess. This 45 year old part that can be a real bitch to locate and if you find one, the owner usually thinks it's made of gold. My first thought after consulting with a friend was to drill the pin out, make a new one, press the bushing out, make a new one, then TIG weld the ear up and use a lathe to make sure that the inside of the ear was 100% smooth. Press the new bushing in. Tap the hole for the pin and use a set screw. But this would take time and I wasn't sure it would even work. So I started looking for a replacement plate. No luck all day yesterday. This afternoon I was finally able to locate a guy that said he had one (although I have yet to see a picture of it). Luckily, he knew me and only wanted $50 for it which I was glad to pay as I've seen plates for the 750 sell for as much as $130. So it should be here by the end of the week. I'm still very nervous and will be until I pull it out of the box and make sure it's the right plate. Usually I don't make mistakes like this so buying this plate has been a real tough pill for me to swallow.

After I realized it was likely that I had found one (this guy actually rebuilds carbs for earlier motorcycles so I trust that he knows what he's got) I took a closer look at what I had. I drilled out a shield on the "pin". It ended up being a set screw after all. So now I may try to fix mine and sell the one that's on the way. We'll see.

The purpose for even opening up the carbs was to replace the stock brass before I installed the new, modern ignition. After that, I will bench sync the carbs again and then vacuum sync the carbs after I get them back on the bike (which should make a big difference). Finally, I'll install the ignition and see where we're at. I'm still having some issues with cylinders 1 and 4 which I believe is because of the bad points. Stay tuned.

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