I got to work on Buzz some last night afterall.

Short version:

Yesterday while testing, the pipe for #3 was cold, the others hot. Injectors check out fine with low pressure bench test. Reinstalled throttle bodies with new silicone intakes and with air filters fitted. Starts and runs on cylinders #1 and #3, pipes for #2 and #4 cold. Verified that all four plugs have spark.

Long version:

I started the bike and ran it for a few seconds, assuming that if the injector for cylinder #3 was not working, that intake tract would be dry. I then pulled the throttle bodies and found that #3 was indeed wet with fuel. I suppose it’s possible that it could be old fuel, but all 4 intakes appeared to be similarly soaked.

I used the pump bulb for a marine fuel tank to put a little air pressure on the fuel rail and operated each bank of injectors with a 12V battery. My fuel pump test power connector is of the proper gender to facilitate testing the injectors. Chalk one up to serendipity. Or maybe my subconscious is better at this than I am. Could explain some other things. Anyway, all four injectors operate identically under this low pressure test, so I don’t think #3 was clogged.

I wanted to shorten the intake tracts, partly to help keep the soft parts short and rigid and partly to make more room for the air filters. Cutting the silicone reducers for cylinders #1 and #4 was easy, just make them shorter. The other two, however, have to also take off a bit of an angle. It turned out to be pretty easy to cut them at a suitable angle. I cut the TB end first, then very scientifically eyeballed the length of the straight ones and cut the intake ends of the #2 and #3 to match.

Somewhere in the months between the first fitting of the neoprene reducers and getting Buzz started a couple weeks ago, I lost one of the larger hose clamps and had to replace it. The 2″ clamps I ordered with the silicone reducers are too wide to fit the throttle bodies and the 1.5″ ones don’t compress enough to fit the intake side, so I had to reuse the hose clamps. Unfortunately, the odd one, the one I had lost and replaced, was about 1/8″ too short to fit the silicone intake. It took a lot of tongue biting and eye crossing to get it to catch and clamp down, but I finally got it.

The throttle bodies are a good inch closer to the engine and the short silicone reducers are significantly stiffer than the neoprene was. I repositioned the support bracket and still had to use a longer bolt to reach, but now the throttle bodies are almost rigidly mounted.

I had to reposition the fuel filter to make room for the #1 air filter. Basically, I just swapped the hoses and put the short one between the tank and fuel filter and snaked the long one between the air filters #1 and #2. The air filter for #4 was still a tight fit to get in place, but once there, it clears the frame that it used to hit.

After reconnecting everything and restarting the engine, it seems that cylinder #3 is working, but now #2 and #4 are not. This is beginning to be a very frustrating problem.

I have one more desperate thought. The fuel I’m using for all this could be kind of old. I think I will drain the tank and refill it with fresh. I think I will also do a compression check. My first thought is that the compression wouldn’t have dropped just because I added EDIS.

Normal troubleshooting would demand that the ignition system be to blame. It was the only major change made at the time the #3 cylinder stopped working, but now that I have removed and reinstalled the throttle bodies and #3 is working, but #2 and #4 are not when they did before just doesn’t make much sense.

I should be able to work on it Friday night and I’ll have another update then.