Pamco electronic ignition with E-Advance package from a 75 engine to an 81

[ffgrose]

First some back story. I purchased a 75 XS650 that was turned into a bobber. It came with a box of parts, another rolling frame and another engine (1981). The PO was selling because he "couldnt get it running right". Upon inspection, someone had smeared RTV around the the cylinder base to stop an oil leak. This did not work. To figure out the "running right" issue, I (and a friend) pulled the carbs to find no main jet in one of the carbs. After a cleaning and installing the correct parts in the carbs, the bike was running much better (still needs bigger mains and pilots). After putting some miles on the bike, the oil leaks were bad enough to cover pretty much everything behind the motor in a nice coating of oil. A lot more then what I would consider as "normal". After some research, the time to pull the motor, replace the gaskets and reinstall seemed a little out of my abilities (I know its not terrible, but i have another motor so what the heck). I recently pulled the 75 engine out to replace with the 81 engine that appears to have new seals in all the right places (cylinder base and head). Correct me if I'm wrong, but I can move the Pamco Electronic Ignition with E-Advancer that was in the 75 to the 81. I realize the 81 has a TDI ignition setup, but I know the Pamco works. Long way to get to the question, but what spacers and bushings do I need to install the advance rod in the 81. I found some parts on MikesXS, but I'm not certain. Here are the parts offered.. Camshaft internal bushing for advance rod, camshaft internal bushing labyrinth seal and camshaft internal cam needle bearing. Also, does any of this require pulling the top end apart. If so, I may reconsider going with the engine that I'm positive runs. Sorry for the long story, just want to provide all the facts.

 

[figure8]

The only thing you'll need to put in the 81 engine are camshaft bushings, there will be 3 to be exact. Everything else from the Pamco will in the 81 just the same as the 75.

 

[ffgrose]

The only thing you'll need to put in the 81 engine are camshaft bushings, there will be 3 to be exact. Everything else from the Pamco will in the 81 just the same as the 75.

Ok. Which ones. It appears there are 3 different kinds. I'm assuming 2 at each end. Where is the 3rd?

 

[figure8]

You put two in the left side I believe, one in the right. Got a link to the 3 your referring to?

 

[ffgrose]

There are 3 different camshaft bushings about 2/3 down the page

http://http://www.mikesxs.net/products-27.html#products

 

[ffgrose]

Also, on the 75 engine, it appears there are 2 bushings on each side. The 81 engine has the same amount of space for bushings on each side.

 

[figure8]

Look here at the Pamco kits, the each come with 3. Those are the ones you'll need.
https://www.mikesxs.net/search.html?q=Pamco

 

[ffgrose]

Ok. Thanks for the help

 

[figure8]

Sure, good luck.

 

[XSLeo]

Go to Pamcopete's web site. www.yamahaxs650.com He is now making and selling bushings specifically for the 80 up engines. These are made to different specs than Mike's. Fit the cam better with less risk of splitting the end of the cam.
Leo

 

[ffgrose]

Awesome. My plan was to freeze the bushings, this seems like a safer route

 

[XSLeo]

I just went to Pete's site, it talks about the new bushings as part of the 80 up kits. I didn't see a separate listing. He has a list of parts you can get from Mike's by item #, but those are the stock type bushings.
Perhaps he will see this thread and respond.
Leo

 

[ffgrose]

I'm thinking the needle bearings mikes offers is the upgrade for the bushings apposed to the labyrinth style bushings

 

[5twins]

Yes, the needle bearing is an upgrade for the stock plain bushings. But on a stock points set-up, the advance rod rotates back and forth to advance and retard the timing. That's why bushings (or the upgraded needle bearing) are used. When you switch to the E-advance, the advance rod gets locked down and no longer rotates. The bushings in the cam are no longer serving as bushings for a rotating part, they are now just spacers or fillers. That's one of the reasons you no longer need all four. The other is that the Pamco rotor that replaces the points cam just spins free. There's not two sets of points putting side pressure on a points cam anymore so I guess Pete figured only one bushing on that side was enough.

My guess is the new bushings Pete has come up with for the E-advance install on the later models are a bit longer than one of the old bushings. One per side is adequate to act as a spacer for the non-moving advance rod. But, I think that kit also includes a new custom made advance rod that differs from an original. What I'm getting at is those new bushings may not be compatible with a stock advance rod. That's something you would need to check on.