1999 AN 250

[ashval]

Dear Forum,

I have retired and more or less rebuilt an AN 250 Burgman to keep me occupied.I know it’s old technology etc,but I want it to run as it was advertised to do.

It has two main problems,which may be related?

1. Poor and erratic running! Starts from cold reasonably ok,the tick over is raised as I would expect,revs drop down as it comes off choke and it eventually stalls,start it again and it is generally erratic until warm. I have experimented with different tick over speeds,but it’s still,erratic.I’ve rebuilt the carb,even bought one of the cheap replacements off E-bay,but went back to the original. I’m almost sure it’s a carb problem,or maybe it’s how these old models were? I would happily send the carb off to a specialist,if I knew one,but without that person being totally conversant with how this scooter should run,I’m doubtful it would be returned any different,unless someone out there knows different.

2, Second problem is poor top speed to how they were originally advertised -85mph. It maybe related to the carb problem,but mine will get up to 70mph and then it’s like a cut out switch comes on. I’ve checked the speedo for accuracy and that’s spot on. Perhaps 85mph is optimistic,and it’s not that I intend to ride at that speed,but after a lifetime in the motor trade,if a motor is not doing what it should,there must be something wrong. New spark plug fitted,air cleaner free,cam timing checked umpteen times,tappet clearances correct,cylinder head off,valves lapped in,exhaust and inlet manifolds mated so no overlapping restricting flow,exhaust checked for resistance,fuel pump operation ok,compression tests done,ignition coil tested and ok etc etc

If there is a member who is willing to contact me and has got a similar AN250,I would very much appreciate a discussion to compare notes. There must be a member with a similar scooter?

[Old scooterist]

Hi there. I have a 1999 400x so apart from the bore much the same. I pushed to get 90 mph on my 400 so don't worry too much.
As I am finding out the mechanical side is fairly basic but the carburator is a beast of its own. The throttle position sensor, ( grey plug) can play up and upset the ecu.
Pleased to hear you choke is working, mine is stuck closed so a pig to start. Lucky we don't drop below 12° here.