kz400 starting issue

[rockcitycafe]

I'm helping a friend out with his 76 kz400, and we had it running a while back, now the problem is strange: timing has been set correctly, compression checked out okay, but now when trying to start, it backfires through the carbs and sometimes will backfire through the exhaust, won't start though, not even with starter fluid... could the carbs cause this?? (p.s. my friend did take the right case cover off and had to put the points back on, though I thought it wasn't possible to screw that up because it can't be put on wrong) (i reset the timing after he did it)

 

[Big R]

I've heard if the mixture is either too rich or to lean (just woke up and can't remember which) it can backfire through the carbs. I'm guessing too rich but wait for somebody else to chime in. Any changes to intake/exhaust since it was running last?

 

[HerrDeacon]

Have you check the valve clearances? Sometimes they can cause backfiring through the carbs.

 

[rockcitycafe]

haven't checked the valves as it was running before and they haven't changed... I wanted to try to narrow it down to things that could be different... not sure if this would change things, but I realized that at his place, we didn't have good tools, and had to use el cheapo digital voltmeter to do the timing, I'm thinking maybe I'd be better bringing my continuity meter over instead?

 

[rockcitycafe]

hahaha... nevermind... the symptoms were of a bike that had the timing off 180 degrees... just woke up this morning and realized the kz400 crank spins ccw at the points cover, whereas hondas are cw, so I was adjusting the timing to perfectly 180 degrees off hahah

 

[dielectric]

hahaha... nevermind... the symptoms were of a bike that had the timing off 180 degrees... just woke up this morning and realized the kz400 crank spins ccw at the points cover, whereas hondas are cw, so I was adjusting the timing to perfectly 180 degrees off hahah

Hee hee. The waste spark fooled you! I suspect you wouldn't have gotten any fire at all on a twin-coil machine.

 

[Stalin321]

Just found this thread, and have a quick question... and yes, I'am reviving this thread for a minute.

So, at closed points, I rotate the crank ccw 180 degrees? Or at open points? anyone got pictures perhaps?

I'm having same exact problem after changing oil seal ring on the crank. thanks for help.