ok what is the "sound when you put the key to "on"? and why would it not go on

[sbrguy]

ok basically today i did one of the ride like a pro classes, all slow speed stuff for a few hours. all below 3k rrpm

got on the bike and basically for a while it was surging, like loseing power, thought it was the gas, but filled up and still had half a tank.

went to start it up 2003 620, and no "whirring sound", gauges sweept and motor cranked but wouldn't start, did this 3 times and nothing.... let it sit for a few minutes and then redid it and it started up could hear the fuel pump start when it was "on".

now while riding on the way home it felt like a couple times that it lost power, the idiot lights didnt' go on, and then an instant later its like it went back on with a surge,

what could this be?

ok figrued somehiint out, the bike wouldn't start again, but the thing that "fixed" it each time was unlacthing the tank tilinting it upwards then putting it back down, the fuses are good...

when the tank was put back down the bike started up you could hear the "fuel pump" or somthing going, what could this be?

thanks.

can you sort of "foul' the engine for a little bit by only doing slow speed stuff for hours.?

[zarn02]

hm...

let's see here. i'm not sure what the cure to your problem would be, or even what your particular issue is (you'll need to wait for someone smarter), but i'll take a whack at a couple things:

the "whirring noise" you hear when you start the bike is indeed the fuel pump.

i don't think that an afternoon of low-RPM work would have any ill effect on the bike. that said, have you pulled your plugs to see how they look?

if you can "fix" the issue by lifting the tank and putting it back down, perhaps you're pinching or pulling a wire somewhere. have you done a spot check of the electrical connections?

i'm not immediately aware of any ECU issues with the '03 620, though i could be simply uninformed on the topic.

what sort of modifications have you made to your bike?

no real remedies from me, but a couple questions to give info that might shed more light on the issue, and a couple of simple things to check out.

[CairnsDuc]

Also check things like Battery terminals are tight, Make sure your Fuses are all OK and sitting tight in there terminals (Physically check them, sometimes they can be a little lose and this can cause arcing within the terminal, but the fuse will look OK from the outside), maybe check the voltage with the engine off and while running to ensure no over or under voltage problems.

[NAKID]

If lifting the tank "fixes" it for a while, it may be that you are pinching the vent hose and the tank is developing a vacuum. Make sure the vent lines aren't pinched anywhere when the tank is properly latched...

[sbrguy]

i did a search could it be that when the fuel filter was replaced a month ago that the lines are now loose?

but the fuel pump like i said sometimes works sometimes doesn't and yes the fuses are all good took them out and checked individually.

[DuciD03]

+1; +1 above;

not much experiance with this one but; pinched / clogged hoses; fuel lines; fuel filter connections; fuel filer installed properly (ie theres an arrow direction for the fuel filer, but that shouldn't effect the flow of fuel) ) and vents is where I'd start; ... air filter really clogged?  Air intake; fuel injectors electrical problem???

.... IF the fuel filter was recently replaced; there are also of hoses in the tank on my bike that would be pinched or knocked off so you may want to empty the tank and look there too ...

the "wirring" sound of the fuel pump should be there; if it isn't then maybe theres a loose connection or your fuel pump is going; I'm not aware of any issues with fuel pumps and if they go there usually just dead.

intresting  .... post the fix when you find it ....

[NvrSummer]

I had a similar issue on my 900, turned out one of the supply lines inside the tank had worked it's way off.  The bike would run but would bog really hard.  Took me forever to figure it out.  Actually happened on a road trip as well, and I had to fix it on the side of the road.

I would recommend popping the cap out of your fuel tank and having a look around to make sure everything is connected correctly.

[erik822]

Did you leave the key in the ignition? That might be the "no fuel pump" part of the problem.

If I turn my bike off I need to remove the key, wait a few seconds and reinsert it before it'll fire again. Something to do with the immobilizer.
I'm guessing you left the key in the ignition. Went back to start the bike, tried three times. and then when it didn't fire you pulled the key out and came back a little later, reinserted they key and then it started.

That in no way explains the surging problem, but it might explain the "whirring" noise.