850GS won't start

[Noely]

Hi Guys

A friend of mines having some trouble with his 850GS, went kaput on him the other day, now, when he attempts to start it it will idle very badly but as soon as you throttle it will cut out, and if you leave ignition on it will constantly activate fuel pump and all you can hear is the fuel pump and a sort of electrical noise? kind of like the noise of a spark plug sparking but its coming from under the tank???

Any help would be appreciated

Noely

 

[Womble]

Just wondering, has he been doing any work on it before the problem? The key thing is whether there has been any work around the tank or the RHS of the bike.

http://www.ukgser.com/forums/showthread.php?t=92541

 

[Noely]

no nothing, last time the bike was worked on was the service about 8 months ago, has been running sweet since

 

[Womble]

My gut reaction says it's the Hall sensor, but it doesn't sound like a 'normal' Hall failure.

Maybe someone who actually has a clue will be along in a minute...

 

[Wrigsby1]

Simplest start is to check the throttle cables are seated at the injectors... 30 secs.

Sound possibly more like an electrical prob though. Don't be shy and remove the tanks and activate the ignition to see if anything is shorting or not connected properly. Many of the connectors control a small charge so corrosion/dirt can feck thing easily but is easily fixed with spray cleaner.

Also possible coil prob. They don't sound too smooth when working on one cylinder

Most of this is very easy and its one bolt to remove the tank...

 

[Noely]

ok, we just removed the tank ( VERY EASY) and all connections seem fine, checked spark of coils and they are both fine

So hall sensor? since i disconnected fuel tank, when i leave ignition on its not doin the sparky electrical fault noise anymore ( don't know if that info helps but....)

 

[Womble]

As Hall sensors tend to be all or nothing, try a few other areas first.

Put the tank back on and start the bike, then see if both exhausts get hot at the same rate - it could be a dodgy lead/coil/plug.

Also, don't discount the fact that the fuel may be contaminated.

 

[Gecko]

better late than never

 

[Womble]

Nope, just late

 

[Noely]

throttle cable is fine, gonna put the tank on and try the exhaust heat thing....we had a spin planned for the weekend....what a nightmare

 

[Steptoe]

Everything you describe points to one of the many different types of hall sensor failure.

 

[Noely]

Thanks a mil guys...it was the hall sensor indeed

 

[motobiker]

Now that IS interesting. I always believed that a hall sensor dies and the engine dies with it. seems thats not always the case.

Cheers for the tip.

 

[Pat]

Now that IS interesting. I always believed that a hall sensor dies and the engine dies with it. seems thats not always the case.

Cheers for the tip.

My 1150 gs did the exact same thing. New hall sensor cured it....Expensive items though

 

[motobiker]

My 1150 gs did the exact same thing. New hall sensor cured it....Expensive items though

when it happened to my bike.. the engine wouldn't turn over at all. The big giveaway was the rev counter needle bouncing round like it was posessed.

 

[Steptoe]

Everything you describe points to one of the many different types of hall sensor failure.

Now that IS interesting. I always believed that a hall sensor dies and the engine dies with it. seems thats not always the case.

Cheers for the tip.

As i said - That was one of the many different types of typical hall sensor failure. There isn't just the one type of failure.