Last week during a particularly vicious cold snap I attempted to start my Burgman 400 (2009). It turned over as normal but didn't fire up.

The battery soon went flat so I attached some booster cables and tried again. After several attempts it fired, a few more and it started and ran for around 30 seconds before stopping again.

After that it would start after a few attempts and each time it would run a little longer.

Eventually, after reaching operating temperature it ran as normal. I rode it for 20 miles or so including a couple of stops and starts without further incident. Then I put it away and put the battery on charge.

Today, a week later, I tried to start it again with exactly the same performance. Wouldn't start all, then ran for a few seconds etc... Eventually running great when the engine warmed up.

Suggestions for what to check in order of simplicity please.

A healthy battery - check the engine / chassis earth and batt terminals, then maybe look to the TPS... Throttle Position Sensor?
Whats the fuel like? maybe top up with new fresh fuel and add some red X?

"Whats the fuel like? maybe top up with new fresh fuel and add some red X?"

Pauls idea is a good direction. this is what id think first, b400 does not like sitting around a while and not being used. many gas tank stories with them of low miles and gas tank issues.

Thank you chaps.

It was a fuel problem. I drained the tank and refilled with fresh stuff and we're all good now.

Nice... Glad ya sorted...