Boxerworks.com

So, back in November, I figured I’d spend about a month or two doing some much needed repairs/maintenance on my 1988 R100 RT. My plan was to replace the timing chain, rebuild the master brake cylinder and replace the brake hoses, have the drive shaft U-joints replaced and replace the leaking neutral switch. So in early December, I started. Well, here I am about six months later finally wrapping it up. Of course, there were plenty of “while I’m there” items that I hadn’t considered that were replaced or rebuilt

For starters, I didn’t expect California to have a record cold and wet winter. The garage was so cold, I delayed going out until it was warmer, which was few and far between. While I looked into a space heater, I just could justify the expense for something I figured I’d use for only a few months. Given the new weather patterns, things turned to very hot relatively quick
Here’s a quick summary of everything I did. If you want a bit more description, see the following post.

Timing Chain (Timing Chain, Crank Sprocket/Bearing/Etc.)
Alternator (New Brushes, New Wiring Harness)
Ignition System (Wedgetail ignition, Wiring Harness)
Gas Tank (Dent Removal, Clean & Reseal, Gas Cap Clean & New Gaskets, Petcocks Rebuilt)
Drive Shaft Rebuilt w/ new U-Joints
New Swing Arm Bearings
Rear Shock Rebuild
Transmission (Neutral Switch replaced, Neutral Switch/Oil Pressure Switch Wiring Harness replaced, Replaced clutch throw-out bearing with newer style, Gear Lever New Bush & Pivot Bolt)
Front Brake Overhaul (Rebuilt Calipers, New Brake Pads, Replaced Master Cylinder, New Hoses and Pipes)
New Rubber Carb Connectors (Also swapped out the carbs for my clean pair)
New Positive & Negative Cables
Annual service

Looking back, I spent about twice as much as I thought I would, but I’m glad the bike’s back in good working order.
It felt good to put gas in the tank and press start. It kicked over pretty quickly, but it ran rough and really couldn’t idle. Some carb adjustments, a warm up ride and some more carb adjustments. Once things were adjusted properly, the bike ran very well.
 

For those who would like a longer more detailed description, here it is.

I slowly worked through each area inspecting parts and electrical wires. I ended up replacing just about all of the electrical wiring that connects to the engine. After 35+ years and ±105k miles, much of the wire insulation was hard and brittle.

While replacing the timing chain, I inspected the alternator, brushes, wiring, etc. I ended up replacing the all the wiring harnesses and the alternator brushes. Unfortunately, I buggered up both electrical connector for the timing/bean can and the ignition wiring harness. I ordered replacement connectors, which I failed at trying to replaced. Electrical connectors like this are a weakness of mine. I ended up buying a new ignition wiring harness; however, the connector to the bean can was another story. The wiring harness on the bean can was also hard and somewhat brittle and the only way to replace them is with a new hall effect sensor. I did not want to try and open the bean can to replace the hall effect sensor. Given the cost of having the hall effect sensor replaced or purchasing a rebuilt unit, I opted to go with an upgrade here. I ordered the Wedgetail ignition sensor. As plus, it eliminates the weights to advance the timing. The Wedgetail was one of the last items installed.

Timing was supposed to be relatively easy using the static timing mark on the flywheel and the trigger indicator on the Wedgetail ignition control module. However, I found it difficult to get it at the point they recommend. The Wedgetail ignition control module has a trigger light and a control module light. The instructions and the video put out by Wedgetail say to adjust the timing can until just the trigger light comes on. However, no matter how I tried, both lights came on. The bike runs OK at the moment, but I wonder if the timing is just a little off. I may just put a timing light on it and see how close I am.

My gas tank needed a dent removed and I found a paintless dent repair place that did wonders. You can barely tell where the dent was. The paint looks a little off, but there’s no evidence of the dent. Next, it was time to drop the tank off to get it cleaned and resealed. Of course, I had to drive 1.0-1.5 hours in different directions to the dent remover and the place the cleaned and resealed the tank. I also rebuilt the petcocks and replaced the rubber seal on the gas cap.

While the gas tank was off getting a refresh, I moved on to removing the drive shaft and sending it off to get the U-joints replaced. Well, the shop I sent it too got inundated with snow and power outages on top of supply /delay issues with regards to getting the replacement U-joint. That took about eight weeks. While the swing arm was removed, I also replaced the swing arm bearings.

While I was waiting for the drive shaft to come back, I moved on to replacing the neutral switch and refreshing the front brake system.

The transmission came out, splines cleaned and lubed. I was prepared to replace the rear main seal and oil pump O-ring if either were leaking. Neither were, so I left things be. I hope Murphy doesn’t come in play here and have it start leaking a few hundred miles after it’s all back together. I had obtained the newest style throw-out bearing from friend years ago and while I had things apart, it was a good time to install it. When I took a look at the wiring harness for the neutral switch/oil pressure sending unit, it too needed to be replaced. While the transmission was out I took a look at the bolt and bushing for the shifter, and they were worn. So, they were replaced and there is much less play in the shifter now. The bushing and bolt for the rear brake lever looked OK, so they were just cleaned and re-greased.

Rebuilding the front calipers went well. Everything was in good condition and they only needed a good cleaning and new seals. Here’s a tip to remove the caliper pistons if you don’t have a air compressor. I do have an electric air pump (110 volt), which I typically use to add air to tires, that worked just as well and the pistons slowly moved out. I also replaced the brake lines (the hard ones at wheel and stainless-steel lines). However, when I got to the master cylinder, things were not as good. The area around the circlip for the plunger was very corroded as was the area where the reservoir connected to the base. Given my limited knowledge, experience and tools, I felt it was best to just buy a new one. I believe it was less expensive and quicker than paying someone to rebuild it, if it even made sense to.

One thing I was in denial about was my rear shock. Last time I rode the bike, I heard some sucking sounds as I bounced up and down on the seat. I figured after 15+ years, the seals had dried up and needed to be replaced. At first, it looked as though I would not be able to get the shock rebuilt. I purchased a Works shock and it first appeared that they were out of business. Well, they sort of were. The guy who started the company passed away and the company was shut down. About two years after that, his daughter (according to their website) decided to start things back up under the name Worx Shocks. So, as I was nearing the end of the refurbishing, I realized the shock should be rebuilt and that I shouldn’t wait until later. Consequently, that was the last major item to come in/back to me. Luckily, that only took about three weeks.

Once everything was back together all the fluids were changed, valves checked, timing set, and carbs adjusted.

Nice! I'm doing something similar with Ernst. I'm calling it a ten-year refresh.

Jeff in W.C. wrote: ↑Sat May 20, 2023 8:16 pm... I found it difficult to get it at the point they recommend.
The Wedgetail ignition control module has a trigger light and a control module light. The instructions and the video put out by Wedgetail say to adjust the timing can until just the trigger light comes on. However, no matter how I tried, both lights came on...
I may just put a timing light on it and see how close I am.

I have a lengthy discussion of my problems installing the Wedgetail unit percolating in my mind, which I will probably post in installments in the very long Wedgetail thread on the site with the white text and black background, but here I would just like to say:

I wouldn't worry about how many lights come on. They don't say ONLY the "Trigger" light. They just say that you set the timing to where the "Trigger" light comes on.
They both come on at once. No big deal.

That being said, i did not feel that setting the timing as instructed was satisfying anywhere but on the side of the road.
I've got the "non-can" points system, which has its own problems (to be discussed another time), but, basically, whenever I thought I'd set the timing just right, I spun the motor over and checked with the timing light and found I was "just wrong."
Back when I used points, and also when I used a Dyna-III, even though it was possible to set the timing with a lamp, I used that only in emergencies or to get an initial setting - I always set the timing at maximum advance, warmed up, which always worked well.
With the Wedgetail, you are not supposed to set it at full advance (mostly because I think that it won't get to full advance while you're just running it in the garage, because of its programming), so i had to set it at the base setting.
My solution was to crank the starter for a few seconds with the spark plugs removed while watching the timing marks with the timing light -- A little pulse, then a tap to advance or retard, then another pulse, then repeat. When I thought it was good, I tightened it up, tried it again, then started it and checked it again at idle to confirm.
The "static timing" technique is BS because it will not give you repeatable results, which is simply bad science and bad engineering.

Also, after having checked the BMW manual, and measured the locations of the lines with an advance timing light, I can say that the center of the three S-lines is definitely the proper timing line. The other two lines are just there to bracket the allowable variation in timing between the cylinders (Yikes!).

As always, "Your mileage may vary."

- Eric

MDchanic wrote: ↑Sat May 27, 2023 6:23 pm That being said, i did not feel that setting the timing as instructed was satisfying anywhere but on the side of the road.
- Eric

I agree with you. It was a good starting point, but was way off. When I used a timing light, the S mark was no where to be seen in the timing window. I eventually got it timed with the light.

The "static timing" technique is BS because it will not give you repeatable results, which is simply bad science and bad engineering.

Static timing is a perfectly valid way of timing an engine, (although I accept it's not as good as a strobe). If the results given when static timing aren't repeatable, then your timing chain is shot or the advance mechanism is sticking

Rob

Having at a very early stage established that static timing on my engine agreed with strobe timing at full advance I have routinely static timed which I believe I can do very accurately and only checked full advance with a strobe every 5 years or so. The relationship between static and full advance doesn't seem to have changed over 15 years and why should it ? Static and full advance are determined by stops that limit the travel of the bob weights. The main thing that might change over time is the rate at which the advance increases not how much it increases. Other than gross wear in the advance mechanism, the only variable is the advance springs which if they weaken may allow the idle timing to drift up and full advance to be achieved at lower RPM than it should.

barryh wrote: ↑Mon May 29, 2023 2:22 pm Having at a very early stage established that static timing on my engine agreed with strobe timing at full advance I have routinely static timed which I believe I can do very accurately and only checked full advance with a strobe every 5 years or so. The relationship between static and full advance doesn't seem to have changed over 15 years and why should it ? Static and full advance are determined by stops that limit the travel of the bob weights. The main thing that might change over time is the rate at which the advance increases not how much it increases. Other than gross wear in the advance mechanism, the only variable is the advance springs which if they weaken may allow the idle timing to drift up and full advance to be achieved at lower RPM than it should.

Agreed... I oinly routinely check with a strobe because it's quick, simple and allows, in fact encourages, an objective check on the action of the advance mechanism... and, of course, I've got one

Rob

My point regarding static timing is specific to the built-in lights of the Wedgetail and not with regards to static timing in general. I think static timing would be easier. However, the built in lights on the Wedgetail did not come on when the unit was rotated very slowly, making it very difficult, IMO, to properly set the timing. BTW, my timing chain and engine crank sprocket were just replaced, so the timing chain can be ruled out in my case.