SECA: Same Engine Crap Again

Is this why nobody wants these bikes?
I have my 750 running GREAT for weeks. I let it sit for a week, then I start it up, let it warm then it dies. I can only get it to start before it craps out.
Last time I went through this I ended up changing the plugs, that worked for a while now it's got the SECA syndrome again. Everything checks out so don't ask stuff like: is there gas in the tank? or did I do a coil test?
Do I have to change plugs every 500 miles?
Bill

 

Not sure what 750 Seca-specific ailment you're referring to... I can leave my Seca parked for a month, and as long as the battery is topped off, it will fire up first bump every time... This is with over 50K miles.

What do the plugs look like right now? Wet? sooty? bone-white? Did you set petcock on PRI for a few seconds before trying to start it?

 

My '83 has sat for a week or more at a time and fires right up.

Likewise my '81. However, it has a less than 100% battery, and will occasionally require a quick "top off" charge if the bike has sat for more than a week.

Remember, it's possible for these things to have a battery strong enough to spin the motor and yet not have enough "juice" left to light the plugs. Maybe you just have a slightly low battery.

 

I can say it started up today on the first bump. It did, but I must have flooded the plugs, it needs to get on the road before I can turn off the choke. Today I tried waiting for the engine to maintain an idle before I pulled out, and that started this current syndrome. I pulled all the plugs and they looked ideal, not wet. It starts up, then stalls. I do prime first as you do. My intention is to wait some hours, then try all over, and then try with new plugs.
The battery is new, and it cranks good. I will try a little charging. It does ignite better when the headlight is off, when the light comes on, it stalls. Is that related, or coincidental?

 

Proto,
Man, you sound SERIOUSLY frustrated! As you know, this problem could be a number of things, fuel-related, from the sound of it. Just don't give up. Have a cold one, ponder the alternatives, check them one-by-one until you locate it. My 750 Max had some issues at first, but, after going through it carefully it is basically bulletproof. Yours will be, too. Keep the faith. Sitting for a week should not be a problem, unless you have water or sediment settling in the tank or carbs. Good luck and keep us posted.

 

Just came from putting a charger on, the bike voltmeter read only 10 volts. I know it reads 14 when running. The charger LED is on meaning the battery is taking in juice. I ran down the battery some trying to restart after the stall, like anybody would.
As for frustrated, I should know better, sorry to whine.

 

Float needle s Old and Worn?? dying Petcock, are the 2 things that jump to mind and fairly typical for these oldsters.. especially if they have not been recently replaced.

 

After a test ride I decided there was a not enough fuel getting to the cylinders. I pulled the carbs, and found one carb had the floats set too low (5mm). Checked all the jets, put the carbs back in and then noticed stuff in the fuel filter. I think that was the problem, so I replaced the filter. The last thing I checked!
Runs great again, idles better too!
Bill