trouble shooting 81 HE restore

[BigJosh]

First post! Been using this forum for a couple months while restoring my FIRST bike - 1981 xs400 HE.

She's teasing me guys.
Cold start is great but after short test drives, getting up to speed and downshifting, dies EVERY time and will not start electronically or by kick. Floods, drains battery, etc.

Within last 2 months has
New spark plugs
New battery
Complete new carb (and gaskets) sonic cleaned twice and pro-tuned
Fresh engine oil
Starter button reassembled
All grounds/terminals cleaned
New fuel line

Looking for a good shop to have it serviced at because maybe compression, spark plugs, engine valves need to be adjusted?
What are the first things to check when a restore consistently runs-great-then-dies?

 

[NewHavenMike]

If youre draining the battery, you could have wiring issues at the coils from the engine. The wires get frayed and become exposed. Your regulator could be bad too. You need to get a fully charged battery and a volt meter to do tests.. You should see around 13.5v at idle.. Im not sure of the exact numbers at the moment, but if youre volts are around 12.5 or below, theres a problem. Volts should go up to around 15.5 when you rev to 3k+

My bike did this after I took it out of Winter storage... The mechanical regulator went bad and didn't produce a charge. Well I rode the bike for a few miles before it stalled.. Id wait a couple minutes and itd be fine until it died again.. This was in the dark too!

If it starts, idles and has some power and doesn't smoke like crazy, you probably have OK compression.

Valves are pretty easy to adjust yourself and all you need is a couple feeler gages. I have a switchblade style master set. You can get them at any auto store or Harbor Freight.

Flooding could be from a bad petcock, or the needles and seats are worn inside the carb. Have you replaced them and set the float heights?

It sounds like an electrical problem for sure though, coupled with a bad petcock or mal-adjusted carb with bad seat/needles.