Bike sputtering - why?
 

Motor was running fine… in 6th gear then bike started to lose power like I'd run out of gas… but I hadn't. Kept riding - every time I opened the throttle it would sputter. Got home thinking dead battery because I had been having a start up problem: 1 out of 10 times I'd take my finger off the starter and it wouldn't turn over - it would stop and when I would push again it would have lost the trip setting / time. Checked battery - it is fine. What else should I check? It has a new spark plug. Checked vent hose for fuel tank - fine. Checked boots for carb - no air leak.

Where is the battery grounded on the bike?

More Info
 

I also just installed a 351 and did the vales and was running a 90/100 watt h4 headlight but pulled it out after the lose of power and replaced with 55/100.
Did I do sum thing wrong in this proses?
I have about 150 miles on the bike sins doing this work.
It dose fire right up and in neutral I can rev it up just fine.
but under a lode it will just bog and sputter.

Thanks for your thoughts:confused:

Sounds like your main jet is clogged but as for the electrical no idea, but it has happened to me before

Another possibility is that the slide in the carb is not moving when you rev it up. Easy way to see if that is a problem is to remove the boot from the air box to the carb and rev the engine. You should see the slide moving up when you rev it-if it doesn't then there is a problem with the rubber diaphragm on the top of the slide.
Get your electrical problem sorted first-that will cause all kinds of running issues.

Yep, that's where I would start. Good Call Frampton. ;)

Ok I will pull the carb and let you know who was right.I will check slide first then main jet and report back. hope one of you gets a thums up! Thanks for your respons.

Pulled the gas tank thinking I was just going to pull the carb and check main jet, then remembered GBAUTO slide idea. pulled the boot on the air box and twisted the throttle without bike started I did not see the rubber slide move. Do I need the bike running? I am going out so I will get to it later today. Thanks again you all are very helpful and I would not be doing any of this stuff without you. ie 351 valves carb thanks again

The slide on stock carb is vacuum actuated. It won't move unless the motor is running. Opening the throttle opens a butterfly valve on the motor side of the slider, which in turn when the motor is running increases vacuum on the air box side. This vacuum is transferred to the top of the carb, upper side of the diaphragm, which causes the slider to rise.

Just put the tank back on and checked the slide it was working. So on to the main jet. If there are other ideas out there bring them on.

When the bike is running and in first gear I noticed it seems fine until about 3000 rpm then the sputtering begins if more throttle is applied it just lurches and sputters.Would the floats have an affect in this situation? Sorry for the lack of basic understanding.Just learning.

Jets are clear. Put carb back on and now have fuel coming out right side vent tube and bottom drain tube.:eek::confused::o