Bike won't start after stalling it. Ideas and theories needed!

[lien]

I'll be as brief and informative as I can about this because I'm still frustrated as hell. lol
This is my first real motorcycle and after three months of restoration I've finally got it started and running. A few days ago I attempted to ride it, or at least fiddle with it in the neighborhood. The thing is, I've never driven a manual motorcycle so it was very new to me. Nervousness and excitement sort of took over when I started the bike and I kicked it into first gear for my first ride. And of course I was so nervous and excited that I didn't even touch the clutch when I shifted so I just immediately stalled it. Tiny hints of smoke started wisping out of my right head pipe, right by the engine. This is because that pipe is a tad bit loose because the nuts are closed ended and the bolts are too long for it so they don't completely seal the headpipe in. I'll take care of that later. So yeah, little bits of wispy smoke. After that I called it a night.

Today I got my helmet in the mail and thought "this is a good time to try that first ride again, SAFELY, and make damn sure to hold that clutch for the first shift." So I set up everything. Made sure my battery was charged, lights working, petcocks were open, opened the gas tank and checked to see if I had enough and good fuel in the tank, and kick started her up. Doesn't work. I try again. It works but it lets out a brief put put put put into an immediate shut off. I try again and try to rev the engine to see if maybe it just needs some helping going. Nope. Just completely ignored my rev and still shut off. So I'm pretty upset because just the other day it was working fine and idling fine and now when I really get a good chance to make this thing go, it craps out on me.
Did I really jack it up from that one time of stalling it or do any of you have other theories? I really hope it's a simple fix. I'm so close to tearing up the highway!

I tried to be brief and I failed. Haha, sorry.

 

[TwoManyXS1Bs]

I'd pull the plugs, inspect them, clean them, reinstall, try restart.

If the plugs were wet and/or dark, you might be over-choking it.

If the plugs were clean and dry, you might be under-choking it...

 

[figure8]

The stalling out wouldn't do that to my knowledge. I can't see your signature right now but a more information would definitely be helpful. What year? What mods? Carbs are clean?

 

[lien]

The stalling out wouldn't do that to my knowledge. I can't see your signature right now but a more information would definitely be helpful. What year? What mods? Carbs are clean?

'75 650B, bike is nearly all new or good condition stock parts so no mods really, and I peeked at the carbs about a week ago and they were surprisingly quite clean.

 

[lien]

I'd pull the plugs, inspect them, clean them, reinstall, try restart.

If the plugs were wet and/or dark, you might be over-choking it.

If the plugs were clean and dry, you might be under-choking it...

Thanks I'll check them out in the morning!

 

[gggGary]

Yes sounds like you wet the plugs I am big on drying them with a propane torch. Kick the motor through a few times while the plugs are out helps get rid of excess gas.
Speaking of excess gas you have known good petcocks? You can remove the fuel lines and no drips? You HAVE gone through the carbs? A full by the carb guide overhaul is the only way. Check for intake, throttle shaft leaks. Sync the carbs, get used to doing THAT on twin cable carbs....
Clean cable routing, well lubed cables are REQUIRED on twin cable set ups. check for up and down throttle shaft slop at the cable arms
A 75 is points ignition if you haven't gone through THAT now's the time. Weak 40 year old ignition and "not quite right" carbs will have you pasty with sweat and pulling plugs on a daily basis.
All that said running a tank of gas through an engine that runs well enough to do it will cure a fair amount of "start up" issues. No matter how careful my carb work I find my bikes run better after they have gone through a few heat cycles and a couple gallons of gas!

 

[peanut]

it might just be as simple as putting the choke on and turning/kicking the engine over with the throttle firmly closed until it starts. providing you synched the carbs reasonably well and set the idle adjust screw so that the butterflys are slightly open it should start.

If you give it lots of throttle when starting from cold it will defeat the cold start mechanism ie slide, pilot jet and air mixture setting and is likely to flood the engine

 

[gggGary]

it might just be as simple as putting the choke on and turning/kicking the engine over with the throttle firmly closed until it starts. providing you synched the carbs reasonably well and set the idle adjust screw so that the butterflys are slightly open it should start.

If you give it some throttle when starting from cold you defeat the cold start mechanism ie slide, pilot jet and air mixture setting and are likely to flood the engine

But I find that cracking the throttle open "just the tiniest amount" is the sweet spot on a cold start. If the carbs had a fast idle setting it wouldn't be needed.

 

[peanut]

I think you are right Gary... every bike has its own foibles some seem to respond well to a severe kicking

 

[XSLeo]

www.amckayltd.com/carbguide.pdf may help you with your carbs. What you think is clean is not the same as what your bike thinks is clean.
The carb guide will help you get them clean. Follow the steps in the guide, don't buy anything till you get things clean and inspected. Often the only thing they need is cleaning.
Leo

 

[hmusket]

Check to make sure your advance weights are retracted, also for your header pipe double check for a gasket, one per pipe, did you use lock washers under the nuts?

 

[lien]

I pulled the spark plugs. They were dry and dark?

 

[TwoManyXS1Bs]

That was 3 days ago? Gasoline evaporates. For wet/rich and dry/lean plug readings to have any meaning, they need to be pulled and inspected immediately during difficult start attempts.

For now, try again, with more choke...