Motorcycle Repair: turns over wont start, 1983 honda nighthawk, starter button

Question
Hi Mark, Any advice you can give me on my 1983 Honda Nighthawk CB650SC?  The bike was running great this summer and I parked it for a few weeks as I just had twins born.  I took it out a couple days ago to start it up for a ride.  It started up ok with a little choking.  It then died and I tried to restart and it turns over good but won't fire up.  I thought it may be flooded so just went ahead and got new plugs and intalled them (it didn't seem that there was a lot of excess gas on the plugs).  Still it turns over but won't fire.  I tested for spark and that was fine.  One thing I tried was moving the kill switch between run and off.  There seems to be a spot between run and off that I actually get the bike to fire a little bit.  I don't know a lot about the electrical but I thought that was curious.  So it seems I'm getting gas and spark but no fire.  Any advice would be greatly appreciated.

Answer
Hi pat,

You may have found the problem.

Check for spark by grounding plugs against the cylinder head to test for arcing. Do this with all the plugs removed for less strain on the battery. Ground all the plugs while cranking engine (prevents damage to electronics).

Work with starter button and engine on/off switch while watching for arcing at plugs. If you have spark, consider the following:

If the engine was running before the twins were born (Congratulations!), I suspect the fuel in the carburetors has varnished a bit obstructing pilot jets and passageways and preventing engine from starting. This is very common and happens in as little as 3-4 weeks of non-starting.

If you need carburetor cleaning files, email me. mshively1@woh.rr.com

See microfiche parts views here: www.bikebandit.com


Respectfully,
Mark Shively