Bike difficult to start

[crazydj]

Hi guys!

 

I have been having problems with my bike for a few months already, since late last year.

 

Symptoms:-

 

Early in the morning:-

1) Bike is easily able to electric or kick start. Once engine has turned on, i just need to rev for a few seconds for the rpm to stabilise and the engine not die.

 

On a hot afternoon/ After a 20 min ride on the express-way, straight away or after a few hours

1) Electric start never works 80% of the time. Need to try and try till i get it. The spark from the plug cap is very weak when electric start but kick start its stronger.

2) I can hear the starter motor turn the engine. I can hear the pistons moving

3) Even so, it is super difficult to kick start. Have to push start.

4) Have to wait till late evening or next morning for it to start easier again.

 

After a long ride, while the engine is hot.

1) Carb overflow hose is emitting fuel vapour. Few drops of fuel leak from the hose. Carb overflow screw is screwed in properly.

 

Things changed

1) Battery

2) Carburettor

3) Rectifier

4) Starter Motor

5) Engine oil

6) Spark plug

 

There are other cosmetic changes but i don't think they are related to the starting. eg: Forks, cowling etc.

 

I am really stuck guys. You guys have any idea what could be wrong or experienced anything like this before?

 

Bike is a 2005 Yamaha YBR125.

 

Thanks.

[Im_A_Rider]

isit rain water go into ur fuel tank?

[Raptor]

Carb is overflowing.

 

Bike starts easily when cold coz its like on choke.. alot of fuel fumes entering the engine during start so it starts easily.

 

When hot... there is more fumes than normal coz the fuel is being evaporated easily and the air that is going into the engine is heated.. so it is less dense.. so your fuel mixture is now too rich that is why you got to crank for a long time before the bike slowly comes to life.

 

Temporary solution is to hold the throttle wide open when starting hot to allow more air into the engine to lean out the over rich conditon.

 

Permanent solution - get your carb serviced and float level setting done by someone who knows what the hell they are doing.

 

On the other hand... an extremely dirty or clogged up air filter can cause the same problems you are describing.

[crazydj]

On the other hand... an extremely dirty or clogged up air filter can cause the same problems you are describing.

 

Air-filter is clean. Its so bad now that i have to push start my bike. Kick-start now only works 10% of the time.