Took my ‘76 CT 90 on its inaugural trail ride the other day in the mountains, 30 miles of Forest Service “ road” shakedown cruise. Started at 5200’ elevation and rode 15 miles uphill to 7700 through some snow, mud and rocky terrain. Probably half of each direction(up and down) was in low range usually second or third gear. Started outside Cherry Az on FR 132 and went to Mingus Mtn and returned in about five hours. Ran on main fuel first leg then reserve on second leg in order to capture as most of the tank sediment as possible and in spite of what I thought was a pretty clean tank the reserve filter was quite full of very fine rust particles at the end of the trip. No problems with the bike at all and I am now one of the “believers “ in the Honda dual range fan club. What an awesome bike for my skill level (modest novice) , budget, and the terrain that surrounds me. It was a bone rattling grin of a ride and has presented another excuse to pull the CT apart for some minor work. I washed the mud/snow residue off after getting home and was not shy with hose except around the gas cap. Tried to crank it afterwards but it wouldn’t fire off. Saw a weak spark in the dark with the garage door closed and figured if it was water induced our 19% humidity was cure the problem overnight. Didn’t happen that way. Checked plug and it was a little wet, fuel flow from carb drain was good. Started pulling panels off as I decided to redo fuel lines in order to make filter change and tank removal more convenient and easier to accomplish, same with electrical troubleshooting. Ordered a new spark plug and bought six feet of fuel line to get my spares supply fulfilled. Electrical system was operating perfectly before this and so I will start with coil supply, plug wire, boot then plug. Then from points work my way back to coil and do a good grounds inspection. Suspects at this point are loose wire, condenser. Battery was at 6.2 volt and water level is good. Put on charger and it came up pretty quickly to 6.8v. Going to pull carb and inspect/ clean as the carb side screen filter behind the small plate had some rust silt residue plus I wanted any electrical to check the main jet size for a possible resizing due to my operating altitude even though the engine appears to be running smooth and pulling good. A plug check after this ride was not a good sample as I was running downhill for a large portion of the last leg at very low throttle that included quite a bit of engine braking. All in all a great ride and great opportunity to tweak some of my prior work on the bike as I hunt for the lack of good spark.
, wires looked good, removed coil with attached condenser and both visually okay. Still learning how to multimeter myself into some level of competency in trouble shooting but not today. Hooked it all back and did a minor corrosion therapy on one of the bulletin connectors downstream of the fuse. Rigged up a fuel supply. Put key in and turned on ( wait for it) !!! . Nothing, Nada, no power to lights. Seems like I kicked it once and saw a really weak spark again. Well damn. No lights so I went back to the fuse and it was blown. I think the Pos wire I was working on must have touched something on the frame and I did not catch it so I changed the fuse with another that was more appropriate, I don’t recall the size. However I did notice something different with the fuse wiring on the new battery and harness I had installed a while back. The original battery harness has one lead that is fused and the other lead, red & white I think, bypasses the fuse so power is always present regardless of fuse status. Well, the newer harness has the red/white branching off after the fuse so nothing can go downstream with a blown fuse. Need to correct that item. All back together once more and kicked it. It does the Honda one kick start and purrs contentedly without the exhaust manifold installed. I’m not surprised by that at all. The original issue of no spark was remains unsolved but other than being curious about it I have moved on electrically. I certainly would appreciate any feedback back on what anyone may think was the cause but even more so I would like some opinions on the main jet sizing, go larger or not. My inclination is for the larger jet and modulate the flow with the needle clip position.