Ran fine last year, now nothing, HELP

[Chrisbobchuck]

I've had my 77 XS400 for a few years now. All i have ever done is drain the gas and put the battery on a trickle charger for the winter. I only use 90 or better no ethanol gas. this year i put fresh gas in and it took awhile, but she fired up and ran great...for three minutes. after that, it would not run. it would chug a little on the starter motor, but never catch and run.

this is my first bike and i never had any one to teach me, so what i know is from this site and you tube.
i took the carbs out and cleaned them step by step while watching a vid on the same carb, the only thing that i didnt touch were the fuel mix screws. i put it all back the way i found it. put in new air filters, rebuilt the petcock (it always leaked). I got fresh gas, she started up on the second kick, i have never even used the kick start, and ran great...for four minutes.

i have done this processes four times now and always get the same results. I know enough to adjust the choke and all, but the shroud of wizardry that encompasses most carbs is beyond me. I understand how they work, but i dont really know what to tune, so that's why i left all of that the same. I pulled the plugs, they were damp, not wet, and one was clean wile the other was black. and they had both spark tested well before i tried to start it.

basically i cleaned the carbs a lot, and nothing changed,

PLEASE HELP!!

 

[amc49]

One plug being clean and the other black says no way are things right there. Black plug is flooded or oiled out and can easily stop starting up. If the clean one is even worse then it never got hot to get black, staying washed clean by fuel to again not work.You may be starting up and easy with a dried up motor but then it floods and dies to not start again.

Dunno much about these but if not electronic ignition then you need to go after your points, they don't stay set forever.

You don't 'tune' carbs that were already set to run well. Meaning stock OEM setup if bike is not modded.

 

[amc49]

Just checked, you have points there, you can't leave those to last forever as they don't. You likely need some adjustment there. Probably way out of whack and being so can easily make trouble like yours.

 

[Chrisbobchuck]

thanks amc49. Sorry it took so long to respond, but i first had to fight with a stripped oil plug and then we had a major house fire! things are getting back on track now and, with all that was going on, I really needed to just go for a ride. I brought the bike in to a local shop, they dealt with the drain plug, adjusted the points and she runs great now.

Thanks!