Bike cuts out when warmed up

[Sycamore]

Hi All

I have a 2010 ER6F.

Starts up fine, yet when warmed up the revs will go a bit lumpy and it'll then cut out, and it wont be happy to restart until it has cooled. Sometimes it'll fire up for a second or two, other times I get nothing at all.
By 'warmed up', I'm meaning ticking over in neutral for 10 mins.

Any ideas?

Spark plugs? Fuel?

Cheers.

[trickywoo]

I'd bet on fuel.

[Alex@POD]

My mate had that sort of symptom on a 675 Daytona, turned out it had spun a main bearing due to a crash and (I think) oil starvation on that side of the engine.

Does the starter sound "right" when you try to restart if after it cuts out?

[Krikkit]

trickywoo said:

I'd bet on fuel.

I'd say this is most likely, try opening the fuel filler when it's warmed up.

After that I'd say maybe something like crank position sensor - once warmed up it's not reading correctly.

[bimsb6]

Choke sticking ?

[archie456]

bimsb6 said:

Choke sticking ?

Pretty sure it's fuel injection.

[Weso]

I'd start by looking at the coils.
Classic sign of a dodgy coil is running worse as it warms up.
Wes

[Sycamore]

So fresh fuel didn't sort it.

Think I'll pull the plugs and coils next.
One step at a time ....

[tvrolet]

I'd be betting something in the electrics breaking down when it gets hot...and not the plugs. Before messing about with fuel and so on, when it won't start take the plugs out and check for a spark. That would be the very first check - if there ain't a spark then it ain't going to fire-up and that would point the finger firmly at something in the ignition. If there is a spark then it's not ignition (but I bet it is).

As mentioned before, coil would be the first thing to check. Then if it's on points check the condenser, or if it's electronic ignition check the crank position sensor (or hall sensor or whatever it's got).

[Mr Squarekins]

I had a cbr600 which did exactly this. I couldn't trace any fault, but a conicidental conversation with a mechanic suggested it perhaps wasn't holding charge, though cold start was fine (!?!).

Replaced the battery, problem was sorted.

[xeny]

I've had this problem when the ignition pickups were faulty. As the engine warmed up they stopped sending a signal to the CDI module to trigger a spark.

Edited by xeny on Thursday 6th April 07:04

[OutInTheShed]

I saw a similar problem on a mate's bike.
The clue was it seemed to be worse if the fuel was low and riding in town.
Turned out to be the fuel pump.
A new generic fuel pump is not expensive.

The ideal way to diagnose would be to measure the fuel line pressure and the pump current, but on many bikes you can hear the fuel pressure regulator working before the engine starts.

Some bikes, a dying fuel pump, or even a nearly-blocked filter can make the pump draw a lot of current which stresses the charging circuit or even flattens the battery.

What colour is the plug?
That's still a clue as to whether you have a sparks problem or a fuel problem.

[fred bloggs]

From my experience with ER6's , the generator is faulty.

[Sycamore]

Figured I'd may as well round this one out having gotten to the bottom of it.

Neutral light switch!

As the bike gradually gets warm, it turns out it was losing its idea of being in neutral, and with the stand being down it cuts it out. I'm assuming that with the heat, the resistance somewhere was just about conking it out. As it would cut out within 5 mins every time, I'd never bothered to try and ride it anywhere and so the stand would've always been down when trying to sort the issue.

£9.85 for the replacment. Doh!

[conkerman]

Was the Neutral light flickering at all?

[Sycamore]

conkerman said:

Was the Neutral light flickering at all?

No, that would've been rather helpful if it had...
It displayed as normal and as you'd expect.
Seems as though the neutral switch was working, but not quite, then working again, etc.
Annoying but there we have it

[spoodler]

Sycamore said:

Figured I'd may as well round this one out having gotten to the bottom of it.

Neutral light switch!

As the bike gradually gets warm, it turns out it was losing its idea of being in neutral, and with the stand being down it cuts it out. I'm assuming that with the heat, the resistance somewhere was just about conking it out. As it would cut out within 5 mins every time, I'd never bothered to try and ride it anywhere and so the stand would've always been down when trying to sort the issue.

£9.85 for the replacment. Doh!

Thanks for bothering to post that... so many stories on the 'net never reach a conclusion. I hadn't seen how old this was and was just about to post re: the various clutch and neutral cut outs. My Legend is sensitive to both, but when wet and cold rather than dry and warm! And years back, I spent a whole summer chasing a similar problem that turned out to be a coil, by the time I'd stopped and checked for a spark, it had cooled enough to be working properly again. Finally found it by the expensive method of replacing any suspect part one at a time...

[bimsb6]

spoodler said:

Thanks for bothering to post that... so many stories on the 'net never reach a conclusion. I hadn't seen how old this was and was just about to post re: the various clutch and neutral cut outs. My Legend is sensitive to both, but when wet and cold rather than dry and warm! And years back, I spent a whole summer chasing a similar problem that turned out to be a coil, by the time I'd stopped and checked for a spark, it had cooled enough to be working properly again. Finally found it by the expensive method of replacing any suspect part one at a time...

We had a similar thing with a yam xt250 it would run and ride for a few miles then conk out until it cooled , turned out to be the ignition pickup with a hairline crack in it .

[bimsb6]

spoodler said:

Thanks for bothering to post that... so many stories on the 'net never reach a conclusion. I hadn't seen how old this was and was just about to post re: the various clutch and neutral cut outs. My Legend is sensitive to both, but when wet and cold rather than dry and warm! And years back, I spent a whole summer chasing a similar problem that turned out to be a coil, by the time I'd stopped and checked for a spark, it had cooled enough to be working properly again. Finally found it by the expensive method of replacing any suspect part one at a time...

We had a similar thing with a yam xt250 it would run and ride for a few miles then conk out until it cooled , turned out to be the ignition pickup with a hairline crack in it .