Hi all,

Took my bike out for a ride after it sat for a number of weeks.
>>Cold/hot starts great and right up.
>>Idles perfectly at 800-900
>>Revs on the stand perfectly and smoothly to about 4-5ks.

>>Rides fine for about 15-20 mins.....then starts to stumble and cough badly, surging in between spurts of power and nothingness!

>>Let it sit for a few mines....everythings fine...then repeats the above.

Please guide with elements i should check

Those symptoms sound like a clogging filter, perhaps replacing the fuel filter will resolve it.

i checked the fuel filter, looks absolutely free flowing if blow into

can it also be bad fuel pump?

Sounds like a hall sensor problem to me, but could also be a bad coil.

An ignition coil will often be the cause of what you're describing after it has warmed up a bit, and also if it is humid or wet when you're riding... but so can the hall effect sensor as stated prior. Very lightly mist some water from a garden mister round the coil area (behind plastic cover at the back end of cylinder head) to see if it 'acts up'. As a coil warms it can, if old or damaged, open up, causing an electrical short.

If not this then remove five allen head screws of the T-shaped cover at front of engine, inset of the timing chain cover, taking care not to disturb the cork gasket - it is fragile if pulled apart quickly. There is the hall sensor. Check for chafed wires, etc. But what can one do but replace that? it is not an inexpensive experiment as it operates on FM.

You can swap the coils to check if its a coil issue.....or substitute a known good coil for one coil, take a run, then swap over the second coil. A very easy test and probably try that before going at the Hall sensor.

my oh my!

and i thought running an injectior system cleans thru the tank would help (

weekend update

1. check the hall sensor wiring, nothing pinched or misalligned.
2. swapped coils and checked wiring around them.

no change.

what now?

Although it isn't classic case of hall sensor it sure is starting to sound like it.
You can get the sensors separately and attach them to the existing plate but not sure how you would go in Pakistan getting them.
This is the source for them in Australia http://www.jaycar.com.au/productView.asp?ID=ZD1900
And USA http://www.bbautomacao.com/home_hall_effect_sensor_cyhme56.html

could well be the fuel pump ....many of us have found the connector that joins the harness to the tank connection to go open circuit

the socket part over time opens up and doesn't close on the pins for good conduction ....this might affect the pump for sure  (a little recrimpling usually restores the connector) ....after a good clean up .

look up deoxit (good for all electrical connections )

I  also would open up under the tank and locate the connectors for the hall sensors ....because they dont get disturbed very often,
 there is a high likelihood that they also could be corroded ....could the heat soak over time and running be affecting this ? I found mine corroded like crazy and nearly to the stage of powder in the connector ...not good for reliability

many think that mechanical oils and fluids is all there is to maintenance ....but that's not the only answer on a efi type system ....electrolysis , and general corrosion of electrical connectors by far outweighs the mechanical problems we find in here on "new to me " running issues ....atmosphere is the key .

good luck !!

Enuff said
Thankyou gentlemen

Good you are back on the road Andy. Next time can you give us some easier questions, not many of us got them right.