[corvair969]

Got stranded today. My 02 f650gs suddendly died down a long descent.
Tachometer behaved strange, jumping all over from 3-6000. And got ticking sound from engine on right side.. and maybe from top
Checked spark. Ok
Checked to see if there was loose connections. No
Starter sounds very bad, and as i was stranded high on a mountain, without phonesignal, i tried to roll start it on my way down..
It tries to fire. But almost as the timing is wrong.

Thoughts are: timing?
: chain jumped?
: broken rocker arm/lifter?

Any ideas?

 

[Godoh]

Ok, bit hard to diagnose from the other side of the planet but.
It could be the old metal filings on the crank sensor. They are a sensor that collects small metal fragments and that stops the sensor working. The most likely place metal fragments come from is the sprag clutch on the starter.
Does the bike sound like it has enough compression?
If the rocker arm is damaged then the bike would have too much or too little compression. There is also a valve lifter mechanism that lessens compression on start. They can fail too.
If the timing chain has jumped then that is pretty easy to see, take the rocker cover off and see if the timing marks are lined up when the engine is at top dead centre.
Let us know what you find
Pete

 

[anthony]

Check battery connections.

 

[kuyajonathan]

Contaminated fuel, refuel recently ? Filler cap-Blocked vent, Blocked fuel filter
Echo battery connections, may spark, can fail under load

 

[corvair969]

Ok, bit hard to diagnose from the other side of the planet but.
It could be the old metal filings on the crank sensor. They are a sensor that collects small metal fragments and that stops the sensor working. The most likely place metal fragments come from is the sprag clutch on the starter.
Does the bike sound like it has enough compression?
If the rocker arm is damaged then the bike would have too much or too little compression. There is also a valve lifter mechanism that lessens compression on start. They can fail too.
If the timing chain has jumped then that is pretty easy to see, take the rocker cover off and see if the timing marks are lined up when the engine is at top dead centre.
Let us know what you find
Pete

Have tear it down. Checked timing ok. The chain and cams look super good.
Crank sensor was full off metal pieces.
The sprag clutch is totalled.. very bad noise when starter ingages.

But cleaned the sensor and put it together.
Still no start.. it wants, and no jumping on the tach..

Can the sensor gotten a smack from the fillings?

 

[Godoh]

Have a look a this link http://www.crossroadz.com.au/F650GS/EngineSensors.html
scroll down to engine speed sensor, then click on the Engine sensor link.
Hopefully that will give you the information you need.
If it is just the spring that is cactus on the sprag clutch then there is an easy fix. Get hold of an oil seal with the same size spring and use that spring to replace yours. Here is the link to a great article on them
http://www.crossroadz.com.au/F650GS/StarterClutch.html
good luck
Pete