I have a VFR400 NC24 and it won't start when cold with the electric start, but however I can jump start it and it starts fine. Once that Bike is warm I can turn it off and then start it with the electric start without a problem ?

Any suggestions

Assuming you are using the choke and it is functioning correctly, perhaps the vacuum operated fuel tap may not be flowing sufficient fuel when cranking. You could try by-passing the fuel tap and then try a cold start.

Could also be a poor battery / bad earth / bad connection to coils giving a crap spark making it harder to start than normal, which would be more evident in cold weather.

I assume you use choke to start and its probably working if it bump starts ok.

If jump starting it is really good right off then maybe just a bad battery. Can you borrow a friends motorcycle battery with similar cranking power and test it. Corrosion will reduce current flow a lot and these bikes are very old. Start at the battery remove and clean and check water level. Maybe unplug and plug connectors to scuff them in the sockets again (be careful to not pull on wires but pull on body of plug).

If that does not help, fueling might be worth a look. How is gas flow out of tank? My Nc24 had not tank filter to plug up but had inline filter (that was ok). My bike was also very hard starting and would not idle well when I got it. I pulled the carbs but kept them together and cleaned one at a time keeping them together. all the jets cleaned using fine wire, put in new float valves and bowl gaskets and intake rubbers. adjusted float height, synchronized the butterflies by measuring them propped half open, set air screws at 2 turns out and made sure choke opened about the same time with the linkage. Invested a couple of days and about 120.00 US$. It starts right up now and idles well. Also, I had to charge batter once when it would not start. When I checked battery it was low on water and topped it off. I keep it on a battery tender now also. It seems to spin over better now. Sometimes you just got to dig into the carbs. I hated to but had no other choice.

good luck.

I have replaced the Battery and the spark plugs. I had to use CR9EH9 spark plugs as I could not find C8EH9 or C9EH9 spark plugs in South Africa. Do you think that could be causing the starting issue ?

RustyRuchy wrote:I have replaced the Battery and the spark plugs. I had to use CR9EH9 spark plugs as I could not find C8EH9 or C9EH9 spark plugs in South Africa. Do you think that could be causing the starting issue ?

I doubt it. They're the same plugs but the 'r' stands for resistor, which stops electromagnetic interference.

Did it start well before you changed the battery and plugs, why did you change the battery?