next time i visit the mechanic i will do the following:

-clean-up the tank and fill up some fresh petrol in it
-check the air filter
-check/adjust the clutch and throttle cable tension

btw..2 more questions:

1. are not they supposed to clean the air filter with air blower, since the air filter of R15 is of dry paper type?
2. cruising at any speed/any gear, if i pull in the clutch, the rev counter is supposed to drop back to idle rpm mark and not to zero, right..??

the answer to both the above questions is YES..paper filters get clogged too quickly if not cleaned properly at service time and also in very dusty environments..the engine never shuts down on its own, there is always something shutting it down

i was just going through some other blogs/forums and one of the write-ups do resemble my problem (For another bike though, Honda CBR 1000 RR). one of the potential explanations go like this:

"fuel cut" occurs when you close the throttle with the engine above some number of rpms (say, 4500 rpm). At this point, the injectors stop working. When you reapply throttle, there is a delay before the Fi system starts working again. If you happen to be holding the clutch in at this same time, engine rpms can plummet to zero and the enging will stall. If you let the clutch back out with enough vehicle speed, the engine will bump start itself back up again.

The answer is to not chop the throttle off in the first place. Its never a good idea to do this and is a bad habit to get into. The other aspect is pulling and holding in the clutch too soon before coming to a stop. You should be properly downshifting until just before coming to a stop, or until engine rpms are low enough. just try downshifting through your gears and don't hold your clutch in until just before coming to a complete stop. It should not stall like this because this is how your bike was designed to operate

Some other guyz have also mentioned replacing cam position sensor to solve this problem.

what are your takes on these opinions? are these technically applicable for R15?

have ridden a r15 myself..there is nothing that matches ur problem..the engine doesn't stall on any r15..yours is a different problem..

yeah...i think so...digging the net i had that impression as well...i have found quite a few owners experiencing the same problem (different makes and models). and, unfortunately, there is no specific reason or cure for it...i just hope my problem has a solution. having a problem, let it be an exceptional one, is not a big deal...solving it IS...

did get the tank cleaned and refilled with fresh octane...checked the clutch cable and air filter...but, to no avail...

the engine still cuts off when i pull in the clutch to slow down from high speed....if i pop the clutch it starts again..does this frequently during the first few minutes,,, after 5-6 KMs the frequency drops quite a bit...i need to twist the throttle just a bit all the time to keep the engine alive... so confusing...

hmmm...then the problem is with incorrectly programmed ecu as far as i can make out...go to the svc and get it reprogrammed(the usual stuff they do at services with the ecu,the CO setting etc)

well, i have posted this problem of mine in the ownership experience thread as well, and i got a very likely cause pointed out by a fellow xbhpian...

it can be a too tightly adjusted Tappet as well, right?
since my mechanic had adjusted the tappets just prior to the morning from which the problem started to surface....i believe the tappet was tightened without maintaining the required clearance levels at both inlet and exhaust end...will check it ASAP.

Ecu.....

dude ur problem is simple, since all r15's come with a closed ecu design they are pre programed with the ignition timing, and that too the ecu's are completely, electronically supported , which is sensor units all over the bike, which measures the outside temprature, engine temprature, rpm counts, fuel delivery, .... every thing.......see now the exact problem is the ecu ,mapping of ur bike is getting screwed up, that happens with some fi engines, for that u have to do is get it re tuned, its just that simple ,for example take a carburated engine ,with out proper air-fuel mixture and the improper idle screw adjustment Ur throttle tends to raise or get lowered according to the varying engine temperature , same is happening here ,this might have been caused by some incidents....... since even if the sensors are giving a wrong feed ur ecu is going to behave in a different way..... i would suggest get ur ecu tuned with a pro,not some regular indian Yamaha mech who cant even find out the problem...... or there are good ecu's available in the market ,both tunable and fixed mapping .... u can get those to fix the problem in ur bike ...... simple

it actually was a case of over-tightened tappets. since the appropriate valve clearance was not maintained, the engine could not "breath" properly in the initial few minutes; untill, the engine used to get heated up and some valve clearance was achieved due to the expansion of metal under hot surroundings. got the tappets adjusted properly and it got cured.

solution

hi dude.

1.check cam timing.

2.fuel injector clean up.

3.change plug.

4.check fuel pump in master filter.

Faced the same prob again