QuestionThis is a weird one... I bought this 1984 V65 Honda Magna a month ago and ride it to work every day (about 10 miles). I use the choke and it starts after 2-5 seconds of cranking. Runs fine. This weekend I used it to run a quick errand and when I came out of the store the bike wouldn't start. It didn't even "try" to start... seemed like it had no spark. I made sure it was in neutral, kill switch off, etc. I cranked for 10-15 seconds... nothing. I tried the choke thinking it might be starved for fuel; still nothing. I cranked off and on for almost a minute. I was baffled. I called my wife and let her know I was OK, but stranded. About 15 minutes later I tried to start it again and it started after 2 seconds of cranking! Now I was even more baffled.
After I got home, I did some experimenting. I let the bike idle til the temp gauge showed 4 bars (199F), then shut it off and tried to restart it after 15 seconds... it started. Then I tried waiting 30 seconds and discovered I had to crank it for 10-15 seconds before it finally started. I then shut it off for 60 seconds and it wouldn't start again for 10-15 minutes!! Vapor lock?? I've had 6 different motorcycles in my life, but never experienced something like this.
Do you have any idea what it might be? Or how I can go about figuring out what it might be? I can't see how it could be electrical or fuel flow because the bike runs perfectly once it starts... Help me Obi-Wan Kenobe... you're my only hope! :)
AnswerKen, these bikes are mostly newer than I generally work with. I am a points and condenser kind of guy in the days before emission controls, transistorized ignition systems and 145HP engines.
A good place to start would be here: http://www.sabmag.org/
When the bike is "not starting" you should be ready to pull a spark plug to check for spark, as well as look for signs of either no fuel or too much, which can give you some clues.
You may well have some electronic components which are subject to intermittent failure due to "hot soaking" for awhile. No doubt about it, a V65 Honda puts off some serious BTUs, and a lot of it gets trapped around the battery box where electronic components live. If you lose spark during the no start condition, then it can be a matter of testing the pulse generator first
http://www.cmsnl.com/honda-vf1100c-v65-magna-1984-usa_model7592/partslist/E++07. then moving up the line for the Ignition module and all the wiring connections between the components, plus the coils and plug wiring. The whole V4 line has issues with the spark units and the SABMAG site has links for you to go to and test/repair the circuit board issues.
http://www.cmsnl.com/honda-vf1100c-v65-magna-1984-usa_model7592/partslist/F++27.
If you determine that you have spark at all times, then you can look at fuel feed issues. Perhaps the fuel cut relay is dying and is slow to get fuel up to the carbs, until it cools down.
Other mystery areas are the ignition switch base, which can detach partially, as well as KILL switch issues including wiring. After 28 years, it is time to pull the bodywork off and go over all electrical connections, including ground paths. Moisture can work into connectors and corrode the terminal connections so that they become sensitive to motion and/or heat/cold cycles.
Heat does radiate upwards/outwards and can affect the fuel tank system in both locations. Make sure that the cap/tank is venting properly, so you don't get into a vapor lock scenario. Check for any vacuum hoses that may have cracked and failed. Carb venting tubes must be clear, too. If something causes them to be pinched off or collapse during heat cycles, it will certainly affect fuel delivery, as well.
More tips here: http://v65.freeshell.org/sabmag/
I wonder if your starter clutch is getting weak and not turning the motor over, despite the sounds of the starter motor in action. They can get intermittent, as well.
I hope this gives you some ideas of where to look for more help and what to check on your bike's mysterious behaviors.
Bill Silver
