No start GS650

[eldoradoman]

If you are holding the choke for longer, then you are giving it more fuel, longer, which could mean you have fuel supply issues, a weak spark, or both. However, 10V is a big drop in voltage, so connector cleanup and/or coil relay mod should help there.

Backfires can be lean or rich. When you say backfiring, is it firing on the exhaust side or back through the carbs and airbox?

I'm pretty sure it's the exhaust that's backfiring, loud snap at the back.

You can hear the misfiring if I hold the rpms up a few thousand, but at full throttle it really boogies just fine. The exhaust will smoke if I hold the choke too long and I smell fuel when I come back from a quick drive.

[BigD_83]

All of that sounds familiar...and pretty much all went away when I switched to the Dyna Greens to get a hotter spark.

it sounds like you are overly rich at low rpms, which could be a symptom of weak spark, but I don't get why you'd have to give it choke longer to startup, that suggests lean.

Do you also get backfiring (crackling/popping) when you suddenly roll off the throttle? That's more typical of a lean condition...

What did you do to get it starting again, and is it consistently starting up for you?

Okay so I got it running again.

[eldoradoman]

All of that sounds familiar...and pretty much all went away when I switched to the Dyna Greens to get a hotter spark.

it sounds like you are overly rich at low rpms, which could be a symptom of weak spark, but I don't get why you'd have to give it choke longer to startup, that suggests lean.

Do you also get backfiring (crackling/popping) when you suddenly roll off the throttle? That's more typical of a lean condition...

What did you do to get it starting again, and is it consistently starting up for you?

I can't really pinpoint what I did to get it going, I just took it back apart and started over, it must have been a loose connection somewhere. It doesn't crackle/pop when I roll off the throttle, just occasionally backfiring while giving it throttle.

Thanks for all the input, I'll go back out and try it again tomorrow and take note of all the symptoms again.

[tom203]

Okay so I got it running again. It's backfiring periodically, more at lower rpm's, less at high rpm's and once it's been running for a few it's a bit better. .....?

It seems to start harder now where I need to hold the choke in much longer also, is that still a symptom of weak spark?

Sounds to me that the low speed carb circuits are plugged.. you said before....
"I did have the carbs apart and cleaned them, but didn't mess with the jets, just adjusted a couple floats."
I'm guessing the carbs did not get thoroughly clean.The "choke" circuits are there to supply additional mixture at cold startup, but the low speed circuits must also supply fuel . To me, the backfiring is a lean condition.

[Nessism]

Sounds to me that the low speed carb circuits are plugged.. you said before....
"I did have the carbs apart and cleaned them, but didn't mess with the jets, just adjusted a couple floats."
I'm guessing the carbs did not get thoroughly clean.The "choke" circuits are there to supply additional mixture at cold startup, but the low speed circuits must also supply fuel . To me, the backfiring is a lean condition.

Agree. Short cuts are long cuts when it comes to the carbs.

Carb rebuild tutorial and Newbie Mistakes thread linked in my signature. I suspect both could help you about now.

Good luck