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Old 01-12-2013, 04:46 AM   #26
777 OP
Adventurer
 
Joined: Jan 2011
Location: Durban South Africa
Oddometer: 69
[QUOTE=It'sNotTheBike;20457293]It is obvious that most of the people who have made guesses in this thread don't
understand fuel injection systems. Of course lack of knowledge doesn't prevent
people on the internet from pretending to know something, but it does impede the
search for the solution if you follow the false trails they create when they make their
clueless suggestions. ( throttle body boot disconnected ? WRONG. )


I've worked with mechanical and electronic fuel injection systems for over 20
years. Based on my hands-on experience, here is MY guess :


I believe your fuel injector is leaking ( when it should not be emitting fuel ) and this
is the source of your hard-start problem as you have described it. When you switch on
the ignition switch, the pump cycles and the fuel injector then leaks fuel and creates an
over-rich fuel mixture which when the bike is warmed up makes starting difficult.
In layman's terms, the engine is being "flooded" with fuel.


The simple test to determine whether this is the case is to remove the injector
from the throttle body and leave it connected to the bike wiring harness and fuel
lines, and place the injector in a clear fuel resistant container.

*****You should have a fire extinguisher handy during this procedure, and ideally
it would be best to do it outdoors rather than inside a building ********

****** WEAR SAFETY GOGGLES or SAFETY GLASSES ( fuel in the eyes hurts ) **********

Then, cycle the ignition switch and when the fuel pump cycles, you should watch the fuel
injector closely and determine whether fuel leaks from the injector. Fuel is NOT supposed to
emerge from the injector unless the engine is being started or the engine is running.

If you DO see fuel come from the injector when you switch the ignition key on, you
need to either clean or replace the injector such that when the test above is repeated using
the cleaned or new injector, fuel no longer leaks when the ignition switch is
turned on. It is difficult to diagnose a problem remotely but nonetheless I am 99%
sure that your problem is caused by a leaking injector.


Please be a responsible internet citizen and report back in this thread when
you solve the problem, so that others who have a similar hard-start condition
can benefit from your experience.

Good luck !

And by the way, if your shop couldn't figure this out, you need to find a different shop.
This is basic stuff, not rocket science, and a mechanic who could not immediately
know what to check after hearing your description of the symptoms is quite simply
incompetent. Of course there are a lot of pretenders out there.




.[/QUOTE Thank you seems to be a solution, also when I twist the throttle fast it does not rev up quickly , my friend twists his throttle and his bike sound very "snappy" when it revs, BTW new spark plug and cap .
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