throwing in the towel soon

I started a custom build on a 76 kz400 a year back. I hard-tailed it, new tank, new wiring, forward controls & did a gasket replace on the top end. After putting it all back together & trying to start it for the last two months, I'm ready to call the local MC shop for help!
Any advise on this would help make this build complete...finally!

So, I've triple checked the cam timing, carbs have been rebuilt, the points worked fine before tare down and are in the same place, I have compression, I have spark, I have fuel, it turns over & backfires.

I can't help but wounder if its something simple like a neutral switch or a timing issue. It wants to fire off but it just wont.

Thank you in advance for your comments.

Hi need more information.
Follow this check list.
1. Spark
Do you have a good spark? Fat blue?
Do you have the spark leads connected right? (common)
Does it fire at the right time (I belive you wrote that you had checked that)
2. compression? (does not need much explanation)
3. Fuel?
Are the spark plugs wet after you have tried to start it or bone dry?
Do you smell gas when trying to start it?
Will start spray help ?

Best regards H

One more thing, You are completely sure that you have enough battery power to drive the starter and the ignition?
My bike has CDI ignition and are probably a lot more sensitive on that matter but a weak battery = backfire.

My initial thought is a weak battery. I get this behavior when I take my bike out of storage.

Very nice build, much talent and vision you have. I really don't get into the bobber seen, but real smart looking bike.

On subject, when I hear the word backfire I know that a valve is open during ignition.

check out:

Cam timing
valve clearance
ignition timing
timing 180 or so out of sequence
firing order

Good luck and stay the fight.

jaggedtoaster2 wrote: I started a custom build on a 76 kz400 a year back. I hard-tailed it, new tank, new wiring, forward controls & did a gasket replace on the top end. After putting it all back together & trying to start it for the last two months, I'm ready to call the local MC shop for help!
Any advise on this would help make this build complete...finally!

So, I've triple checked the cam timing, carbs have been rebuilt, the points worked fine before tare down and are in the same place, I have compression, I have spark, I have fuel, it turns over & backfires.

I can't help but wounder if its something simple like a neutral switch or a timing issue. It wants to fire off but it just wont.

Thank you in advance for your comments.
]

see if the advancer mechanism is installed 180 out.