M900 Cutting out

[CarloL]

Hi

1997 M900

Cold Monster keeps cutting out even with the choke on , got it to idle after it warmed up and with some persistent throttle to stop it dying , but if you give her too much throttle she cuts , feed throttle and slip clutch it cuts , on a hill she instantly cuts if you try to put load on the engine , new plugs ,oil and oil filter , fuel filter about 100km ago

any Idea's ? Fuel related ?

I did notice rust sediment in the old Fuel Filter

Any advise on how to approach this , test procedures?

Fuel system cleaner , redex type products?

Carb needs cleaning ?

thanks

[IMG]blob:https://web.whatsapp.com/1d45d986-628b-4f8a-9d7c-c32c09771cf9[/IMG]

[utopia]

The rust sediment sounds a little ominous but ...

At this time of year, are you sure its not carb Icing ?
A dose of ProFST in the fuel should sort that.

Back to the rust, it might be worth draining the floatbowls and seeing what comes out.
You may even have water in there, in addition to further rust sediment.

I might also be inclined to drain (or at least siphon and flush) the tank.
Again, you might even find water in there, perhaps from condensation during storage.

Anything to avoid having to strip the carbs out completely really.

Further along ..... fuel pump could perhaps be an issue.
I'm told that they don't like standing idle for long periods as the diaphragm can dry out and perish.

For my money, first job drain floatbowls, maybe also flush tank, and also try some ProFST.

[Dukedesmo]

As above icing is a possibility but I had similar symptoms on my Moto Guzzi last year, it would start and run fine but would cough and splutter at high RPM under load.

I took the float bowls off and they had small bits of tank rust/sediment/water in them, not a lot and not enough to block anything fully but enough to kill the main jet when sufficient pressure was pulling them up the spout.

Fortunately cleaning out the float bowls on a Guzzi is only a 5 minute job, given their outboard location - takes a bit longer on a Monster but then a Monster does have a proper filter so a less frequent operation.

[Darkness]

How old is the fuel?
That sounds a bit like "gone off" petrol with ethanol in it.
Try syphoning the old stuff out and replacing with some nice new Esso Super Unleaded.

Edit: Can you still get ethanol free petrol in Dublin?

[CarloL]

Originally Posted by Darkness

How old is the fuel?
That sounds a bit like "gone off" petrol with ethanol in it.
Try syphoning the old stuff out and replacing with some nice new Esso Super Unleaded.

Edit: Can you still get ethanol free petrol in Dublin?

Thanks

Bike is used 5-6 days a week , I only filled up the fuel about 2 days ago, she was running great after I serviced her

Maybe the low tank of fuel caused the fuel pump etc to clog up

you can only get 95 crap here , all petrol is obligated to have 7% ethanol

[CarloL]

Originally Posted by Dukedesmo

As above icing is a possibility but I had similar symptoms on my Moto Guzzi last year, it would start and run fine but would cough and splutter at high RPM under load.

I took the float bowls off and they had small bits of tank rust/sediment/water in them, not a lot and not enough to block anything fully but enough to kill the main jet when sufficient pressure was pulling them up the spout.

Fortunately cleaning out the float bowls on a Guzzi is only a 5 minute job, given their outboard location - takes a bit longer on a Monster but then a Monster does have a proper filter so a less frequent operation.

Originally Posted by utopia

The rust sediment sounds a little ominous but ...

At this time of year, are you sure its not carb Icing ?
A dose of ProFST in the fuel should sort that.

Back to the rust, it might be worth draining the floatbowls and seeing what comes out.
You may even have water in there, in addition to further rust sediment.

I might also be inclined to drain (or at least siphon and flush) the tank.
Again, you might even find water in there, perhaps from condensation during storage.

Anything to avoid having to strip the carbs out completely really.

Further along ..... fuel pump could perhaps be an issue.
I'm told that they don't like standing idle for long periods as the diaphragm can dry out and perish.

For my money, first job drain floatbowls, maybe also flush tank, and also try some ProFST.

Thanks!

Will do , I want to POR treat the tank this summer

She was on low fuel light so I reckon the fuel pump picked up all the crap

Wahts the best way to clean out?

[slob]

Originally Posted by CarloL

... I only filled up the fuel about 2 days ago...

When did the problem start? ...Duff batch of fuel?

When was the air filter last cleaned/replaced?

What do the spark plugs look like?

Igniter box(es) or coil(s) failing?

[CarloL]

Originally Posted by slob

When did the problem start? ...Duff batch of fuel?

When was the air filter last cleaned/replaced?

What do the spark plugs look like?

Igniter box(es) or coil(s) failing?

The only thing that changed is new fuel

Will take the plugs out and check

Air filter is as new, 5 month old K&N

[slob]

Drain the tank and floatbowls, stick a gallon of fresh in. If that fixes it get rid off the duff stuff a pint/per tankful in a car (if you have one)

[CarloL]

Thanks lads

I had a look online and youtube , how do you drain the floatbowls, I comprehend via the screw but where is it on the bike , under the airbox

What exactly is a floatbowl, used for?

[Darren69]

A floatbowl is used to regulate the fuel flow into the carburetpr and also to maintain fuel height/pressure in the main jet and venturi which will affect the air/fuel mixture.

[CarloL]

Thanks Darren , every day is a school day

all I can see is the ball cock in the Toilet tank :P

[CarloL]

With a K&N Filter and Termi's , do you guys get the bikes fettled ? Carbs re-tweaked?

[Darren69]

Originally Posted by CarloL

Thanks Darren , every day is a school day

all I can see is the ball cock in the Toilet tank :P

Yes similar principle, it stops and starts the fuel from flowing and more importantly maintains a constant head of fuel available for the main jet, if the pressure/level varies too much then too much or too little fuel will be sucked in.

The engine will still run with air box and exhaust mods but may well be weak or not ideally setup which may cause heat damage. or running issues, flat spots etc. So tuning is advisable and a dynojet kit with modified jets and needle will ensure more accurate fuel control and better performance all round.

[CarloL]

Thanks Darren

One of the lads said this is a great site for the Monster , how to do mechanics

http://www.ducatisuite.com/basicmaintenance.html