CB350 Engine PROBLEM!

My dad and are in the middle of an overhaul on my 350. rebuilt the engine last fall and recently sorted out the wiring. trying to fire the bike up on the bench has been a fail so far. Sputters and huge backfires like the timings off but everything is spec'd according to the manual and timing sprocket and crank marks are all properly aligned. This last time he had tried to start it after confirming the valves were adjusted properly he noticed the left plug was completely dry and right was wet. Both carbs seems to be functioning properly and bowls are filling up but still the same sputtering and backfiring. he's out of ideas and I barely had one to begin with. Thoughts?

Have you set points gaps and timing with a test light or multimeter? Have you at least bench synced the carbs?

advCo said:

Have you set points gaps and timing with a test light or multimeter? Have you at least bench synced the carbs?

Click to expand...

Yeah the timing was set with a test light and carbs were bench synced.

Spark advance 180 degrees out? Should run at all if that's what you mean by sputter but it'll backfire like a mofo.

carnivorous chicken said:

Spark advance 180 degrees out? Should run at all if that's what you mean by sputter but it'll backfire like a mofo.

Click to expand...

Exactly what I was thinking, happens a lot.

carnivorous chicken said:

Spark advance 180 degrees out? Should run at all if that's what you mean by sputter but it'll backfire like a mofo.

Click to expand...

Sorry I'm not in front of the bike. He's telling me it's keyed and can only go in one way and doesn't understand how it can be 180 out. thanks for the replies, guys.

The center of the advance unit can be installed two ways; one correct the other incorrect (180 degrees out). So, your ignition could be going off on the wrong stroke.

coil wires? swap them?

justahunk said:

Sorry I'm not in front of the bike. He's telling me it's keyed and can only go in one way and doesn't understand how it can be 180 out. thanks for the replies, guys.

Click to expand...

Nope, spark advance can definitely be installed 180 degrees out. Ask me how I know...

So my dad was able to get into the bike and flip the advancer 180 and says the right point is opening half a turn before it's supposed to open when trying to set the timing. basically saying that since he's flipped it 180 the timing is impossible to set. I found a post about what seems to be this same issue on the forum that was never quite resolved. Thanks for all your guys help so far, much appreciated.

http://www.dotheton.com/forum/index.php?topic=25197.0