Join Date: Mar 2007
Location: Victoria, British Columbia, Canada
Model: GL1500, 172,000 KM
You can run the engine with the air filter out and visually check the slide travel while snapping the throttle. If you have a sticky slide hit it with a few shots of silicone spray and work it back and forth with a finger.
When I first bought my 1500 years ago it had a terrible backfire and stumble. Took it to a Honda dealer who charged me $137 for supposedly lubing the enrichment valves (yeah sure) and of course no change. They then said the next step was a carb out service at around $1000. I went home and learned my way around the bike and first thing i found was a broken spark plug insulator. Not noticeable till you rotated it in your hand and watched as it moved. Cracked at it's base it would slide up the electrode and snuff out the spark, cylinder filled with unburned fuel/air then next cycle pop bang. New set of plugs and problem solved. I learned to start simple and pay attention to small details.