Hi guys, wonder if you could point me in the right direction. Had this bike 2 years with no issues at all until last week. She started chugging like she was running out of fuel, but would surge forward after 6-7000 rpm. Switched to reserve and filled it up with fuel, and the issue was the same. Just acting like it was running out of fuel. So had the carbs cleaned and changed the oil. Plugs look good, less than a year old.

Problems seemed to go away for a day after carb cleaning, until today. Riding along at about 7000 rpm and the bike just shut off. No hesitation, no chugging, just shut off like I hit the shut off switch on the handlebars. Bike wouldn't start, lights came on, engine turned over while pressing the start button, but wouldn't catch. I figured fueling. The fuel pump (I guess? The fuel lines coming out from underneath the fuel tank has an inline fuel filter maybe?) clicks when I turn the key on. After 30 minutes it started right up no problems, so headed home, stopped at several stop lights, bike idled fine, temp was good, and was turning onto my road when it suddenly turned off again. This time 1st gear maybe 5-6000 rpm. Now it has been sitting an hour and no go. It is not vapor locked, I opened the fuel filler cap, no rush of air, checked the breather tube, and all is fine there. There is fuel in the tank, tried switching back and forth between reserve and normal, no difference.

Could it be a bad fuel pump? Fuel relay? Bad shut off switch on the handlebars? I am grasping for straws. Any help will be much appreciated.

Check the vacuum hose between tap and cylinder head for leaks, but if it shut off instantly then more like ignition.
There is no fuel pump as standard, but some times fitted to race bikes.

Look at wiring connexions, if it cut out whilst turning, then try running the engine and turn bars lock to lock a few times.

Well I checked and verified - good fuel flow to carbs (there is some kind of in-line fuel pump), good power, but no spark to either of the rear 2 cylinders (didn't check front 2 as the bike should power up even on just 2 cylinders). The coils seem ok, so I checked the regulator rectifier and the wiring harness is crap. It looks burnt and has a burnt smell. Could that cause it to just cut out? Tried another one off my second NC30 and still no start, but am not sure if that one is good either, as that bike is currently not running.

Burning wires are never good, and the charging systems on these bikes are notorious for going from often ending with toasted wires/connectors and in the worst case toasted reg/recs and even the ignition, plus ruined batteries.

As it is so common, it could just be coincidence and your issue lies elsewhere. There are loads of threads on this forum about fixing damaged charging circuits, so if the wires and connector look nasty, it would be worth sorting those out anyway. Maybe the charging circuit isn't working properly and the battery is unable to sustain a spark, however you haven't suggested that battery is going flat, so it seems unlikely.

I'd make sure both coils are properly connected to the wiring loom and that they have the right resistances. I'd then check the kill switch circuit to make sure that it is operating correctly, and has no dodgy wires. I think the connector is in a different place on the VFR, but my RVF died at about 9000rpm not that long ago due to the connector having excessive corrosion in it. A good clean of the pins and so far all has been well again.

Thanks for the info. I am on my way to Chinatown to grab new wires and connectors. Gonna sort those out first whether it is the issue or not as you suggested. I kinda thought it might be the kill switch as the engine just dies but all the other electrical work - lights horn etc. So will check the kill switch tomorrow as I am replacing the reg/rec wiring.

clickin is most likely a dead battery, many "fuelling issues" can be caused by a dying battery too.

sounds like your charging systems toasted.

maybe need a new battery too if its over-cooked it.

Follow the charging system diagnostics guide and test genny, genny output and reg/rec output.

clean all contacts fully between reg/rec and genny and reg/rec battery and measure voltage at idle and 5000rpm with / without lights

mesuare your batt voltage, probably dead so needs a charge, fully charge it with a battery charger, the bikes charging system isnt designed to charge a dead battery

Had the same problem a short while back. Turned out to be a faulty kill switch.

well it turns out it was (hopefully only) the burnt wiring at the reg/rec. i replaced all the wiring and soldered new leads on everything and she started right up and no problems while on a short 10 minute ride tonight. tomrorow will take it out for a little more punishment in the sweltering hot Bangkok weather and see how she holds up to 38 degree weather we are having

bkk2009 wrote:well it turns out it was (hopefully only) the burnt wiring at the reg/rec. i replaced all the wiring and soldered new leads on everything and she started right up and no problems while on a short 10 minute ride tonight. tomrorow will take it out for a little more punishment in the sweltering hot Bangkok weather and see how she holds up to 38 degree weather we are having

Have you checked the battery voltages?

For 5 minutes that it takes to check it can save you the pain of burning out your ignition box.

Well I have found the problem. CDI is burned out. Are there any alternatives from other bikes? I am looking for low cost, as I am job hunting and need one working commuter bike. They are very hard to find used here and new parts are expensive to ship to Thailand, as Customs taxes these items at 120% of the value of the item plus shipping, more than doubling the price of the item purchased.