starting engine difficulties

[richard1958]

My 2009 grandvista 250 has never been as robust at starting up engine as I would like.  Even after adjusting the valves and replacing the spark plug.  When the engine is cold I've found that if I don't turn the throttle it almost always starts right up.  In this condition if I use even a slight turn on the throttle it won't start and floods.  When the engine is warm I have to give it slight throttle say 1/8 turn and it usually starts right up.  In this condition the 'no throttle' method doesn't work.  Has anyone else had this experience?  Thanks.

Rich

[BettinANDlosing]

Yeah pretty normal on the 250's. Although it's more likely it's not flooding, when you open the throttle the engine is actually getting LESS fuel. The 250 does have a mechanical accelerator pump that squirts a tiny bit of fuel but this is not enough to flood the engine. What is your fuel mixture setting? when is the last time you went through and cleaned all of the jets and passageways? Air filter has an effect, as does air temp. and barometric pressure. My 250 is the same way, fires right up no throttle cold (because the bystarter) and after it's warm it needs a little throttle opening. When the bike is warm, it still turns "on" the choke when the key is off, so when you go back to re-start the bike is too rich because of the choke. If your bike is totally stock your fuel mixture should be 2-1/2 to 3 turns out, closer to 3 depending on where you live going into winter! GOod luck!!

[mrbios]

Has anyone else had this experience?  Thanks.
Rich

My 2005 GV250 does the same thing.  I believe this is because the electric choke aka Auto Bystarter applies the proper choke when the motor is cold.  But after driving and shutting the engine off for 15 min or so the motor is detected as being warm so the choke does not come on which is why it won't start without twisting the throttle 1/8 to 1/4 turn.

[windwheeler]

My buddy and I have (had) together 4 Grand Vistas.  Some started well, my present one needs 1/8th of a throttle turn.  The major difference I figured out is how rich the pilot jet is set. It needs a looong small flat head screw driver to turn it.  Turn in clock wise is leaner, turning out is richer. Also, the auto-choke stay open (rich) differently; on one Grand Vista that started really good it was annoying to me how long it idled quite high, due to the choke.  I like the short active choke time on my present  G/V much better.

Richer setting gives you better starting, but will decrease MPG's, as much as 5 MPG  (my riding is quite spirited). So, there is a compromise between good starting and best fuel efficiency.  Your choice.

[mrbios]

...
Richer setting gives you better starting, but will decrease MPG's, as much as 5 MPG  (my riding is quite spirited). So, there is a compromise between good starting and best fuel efficiency.  Your choice.

Good info.

[Rudolf]

I also had engine starting difficulties, turned out that the air filter (that I've never checked) was clogged with dust from the road mixed with gasoline and water that made a mud like consistency on the air filter paper element. The top speed was also reduced to a maximum of around 85 km/h.

[BettinANDlosing]

My 2005 GV250 does the same thing.  I believe this is because the electric choke aka Auto Bystarter applies the proper choke when the motor is cold.  But after driving and shutting the engine off for 15 min or so the motor is detected as being warm so the choke does not come on which is why it won't start without twisting the throttle 1/8 to 1/4 turn.

It actually come from the fact that the bystarter turns back on! The bike itself does not "know" that it's warm or cold, the bystarter turns back on whenever the key is off for more than a few minutes, so you come back to the warm bike and the choke is on when it doesn't need to be, when you crack the throttle you are letting more air in and less fuel.