Nick wrote:The first problem I see in many of these threads are the words: "was adjusted," or "was rebuilt," or "I had it rebuilt." In other words, you let someone else work on your bike.
If you didn't do the work yourself you should assume that it wasn't done properly. The sad reality is that many self-styled, old-bike experts out there don't know what they're doing. Or, if they do, they're too lazy (drunk, on drugs, etc.) to do the job properly. In other words, if you want it done right, do it yourself. If you don't know how to, learn.
Anyway, enough rant. All trouble shooting starts with a comprehensive tune-up. That is, everything set as per the manual. Here's a partial list:
Points gap set as per the manual. If the bike's been sitting, use a points file or some wet/dry paper to remove the oxidization from the contact surfaces. Clean points, put a small dab of grease on points cam.
Sometimes, even after you clean the points you still don't get spark. One simple test is to use a flat-bladed screwdriver to open/close the points manually while watching for spark at the plugs. If you get spark, it means that everything is okay, but that the points contact surfaces are still not clean enough.
Timing checked with strobe
Carbs completely stripped, all metal parts soaked in lacquer thinner then blasted with with compressed air. All jets checked for proper sizes (see manual), all jets free and clear, carb mounting flange checked for flatness, new O-rings on carb manifold (put some grease on them, don't over tighten nuts! That's what the lock washers are for), float level checked, slides lifting simultaneously, fuel flow checked with float bowl off, etc.
Valves adjusted as per manual
Cam chain adjusted
Plugs clean and properly gapped (see manual). Usually no need to buy new plugs, just sandblast them clean and re-use.
It sounds silly, but when everything is right, they run right. It it's not running right, something's wrong (duh!).
Only after you're sure that all the basics are correct can you do effective trouble shooting.
Here's a hint: it's usually the points, the carbs or a bad rectifier not charging the battery.
Do what you've always done and you'll get what you've always had.
