Motorcycle Repair: Honda CB250, new south wales australia, air leaks

Question
Hi, My name is Aaron from Sydney New South Wales Australia
I have recently got myself a 1998 Honda CB250, it is a great bike but i am finding it difficult to warm up, it loves the choke but even after 5-10 mins of warming it dies as soon as i take choke away. I notice that i am getting carbon build up on the left exhaust too, does this have something to do with my idling problem? thanks heaps

Aaron

Answer
Hi Aaron.
 There are a number of things that can cause an engine to quit, even when warmed up.

 You should check the following;

1)  Air filter.  Is it clean and servicable or is it due or overdue for replacement?

2)  Carbs.  Are they synchronized properly?

3)  Valves.  Are they set correctly (gap and timing)?

4)  Ignition timing.  Is it set correctly?  On a 98, it probably resets itself with the carb synch.

5)  Check to make sure that both of the chokes are not sticking closed after the bike is warmed up.

6)  Make sure that there are no shorts or hot grounds in the ignition wiring and that all ignition components test to specs.

 As far as the carbon buildup in the exhaust, check to insure that both carbs are secure in the manifolds and the manifolds are secure to the head.  Make sure that there are no air leaks in the manifold area at all.  Running it for more than a minute or 2 with the choke on will also cause the engine to run rich.

Starte with that and see what you find.
Good luck.
FALCON