Need some help diagnosing a $700 bike

[mr72]

That 20 minute mark is right about how long it takes to warm up.

Could be ignition, that can be heat related. Check the "signal generator", that is a hall sensor under the cover on the right side of the engine. The test is to hitnit with some kind of compressed air or freeze spray to cool it when it's hot and the bike is not running, see if it fixes itself. If that's not the issue, could be one of the ignition coils or the igniter/CDI.

Do some searching and you will find good info on this.

Of course it could be bad compression. When mine had bent valves it behaved the same way. A compression test is easy and warranted.

[Bluesmudge]

I agree with mr72. Happened to me with my 2006 GS500.  It was the signal generator. Very hard to test it because it will always test okay when cold. Heat was causing a short somewhere. You just have to replace it.

[mr72]

technically, heat causes it to OPEN when it's bad.

[Bluesmudge]

You are right. I know how to use a voltmeter to check my battery and beyond that my electrical expertise is: replace things until it works again.

[The Buddha]

You can actually test that crank trigger - when its hot and is refusing to start, take off that round right cover and spray it with a can of compressed air.
It could cool it to get it to restart. If so, you replace that and you're good.
Cool.
Buddha.

[Bluesmudge]

You can actually test that crank trigger - when its hot and is refusing to start, take off that round right cover and spray it with a can of compressed air.
It could cool it to get it to restart. If so, you replace that and you're good.
Cool.
Buddha.

oh like...

The test is to hitnit with some kind of compressed air or freeze spray to cool it when it's hot and the bike is not running, see if it fixes itself. If that's not the issue, could be one of the ignition coils or the igniter/CDI.

[The Buddha]

Bwaaa ... he beat me to the punch.
Cool.
Buddha.

[IUsedToWrenchCars]

That 20 minute mark is right about how long it takes to warm up.

Could be ignition, that can be heat related. Check the "signal generator", that is a hall sensor under the cover on the right side of the engine. The test is to hitnit with some kind of compressed air or freeze spray to cool it when it's hot and the bike is not running, see if it fixes itself. If that's not the issue, could be one of the ignition coils or the igniter/CDI.

Do some searching and you will find good info on this.

Of course it could be bad compression. When mine had bent valves it behaved the same way. A compression test is easy and warranted.

You can actually test that crank trigger - when its hot and is refusing to start, take off that round right cover and spray it with a can of compressed air.
It could cool it to get it to restart. If so, you replace that and you're good.
Cool.
Buddha.

Man, you guys are sharp and helpful! Great minds definitely think alike  I'm gonna try the compressed air on the signal generator today after work and then I'll compression test it either today or tomorrow after I go pick up a used stock exhaust from Florence. You guys are awesome! 

[The Buddha]

Invert the can of compressed air and spray. But also ride with that round cover off first, the cover doesn;t have oil behind it, its just to protect in case of a crash- Yea dont crash on the right, just crash on the left with that cover off.

BTW Florence ? SC ? My area. How dare you buy a GS from my area. How dare you make fossil fuel co2 bla bla bla world is going to end in 20 mins and how dare you bla bla bla ... make co2.

Cool.
Buddha.

[Bluesmudge]

Old man Buddha is drunk again.