Making progress, but still wont idle!! (Video works now)

[bennecc]

So I have been trying for days to get this thing ('81 w/ stock carbs) to run. It was running until a few days ago when it died and hasn't wanted to start since.

I've pulled the carbs 3 times, so I'm pretty sure they're clean; mix screws are 2.5 turns out. Compression is good. I have adjusted/checked valves 3 times also. I have a Pamco ignition; I did my best to check timing using a light while kicking it over and timing seems good. Battery is freshly charged, 13 volts.

Then last night I pulled the baffles out of the mufflers which seemed to help! Now at least there is combustion and it will sometimes run for a few seconds. There's some popping/backfiring when it does run. It wont idle anyway, but if I give it any throttle it dies even quicker.

After the start attempts the plugs are black and barely wet.

Any suggestions?

 

[twinsarehot]

video is set to private.

 

[bennecc]

Whoops, it should be fixed now. Thanks for the heads up.

 

[Travis]

So it was running just fine until a few days ago and then it just randomly stopped working?

Try new plugs first and if that doesn't help much see if it'll start with no throttle and no choke.

 

[bdholsin]

Stupid question but I'll throw it out there...does it have enough gas in the tank? I'm not trying to be a smartass.

 

[Earz]

Is that the longest you've gotten it to run? If you let it idle will it run longer?

If it will idle and run longer, I'd think that maybe the float height is set too low not allowing the bowl to fill as much as needed. When you give it throttle, there is not enough fuel in the bowl to keep up with what's needed for the engine to run at RPM.

If float height is ok, I'd make sure that the float bowl vents are not clogged. This can also reduce the amount of fuel that goes to the bowl. (similar to plugging off the top of a drinking straw while it is submersed in your drink. When you lift the straw, the liquid stays inside. As soon as you move your finger, the liquid pours out). I've seen the bowl vents plugged on dirt bikes & atvs more than street bikes, but older bikes have to deal with flying insect nests, mouse nests, etc if they have been sitting.

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[bennecc]

I think its fixed!

A couple days before it stopped running in an attempt to quiet it down I had put a drag baffle inside the baffle that comes in the short reverse cone mufflers I'm using. I was able to get it started today with all the baffling pulled out, but barely a pop with them put in. So I pulled out the drag baffles and put back in the regular baffle and it seems to run pretty good. It idles nice and I even took it for a put down the street ; it finally died when the fuel bottle ran out. Shifts kinda clunky though, I almost never found neutral.

The strange part is that it had started and ran 5 or so times in the garage/driveway with the drag baffle setup.

Now that it seems to be running again I noticed 2 things.

1 is that there is a lot of smoke that I think is coming off of the header wraps. Maybe because its the first time they've gotten hot? Or maybe its the bbq paint on them? Anyone know if that is normal?

The other is that it takes more effort to kick it over now. After I got the baffles shoved back in (the packing is all messy now after pulling them out so many times, so it takes some effort to get them in) I stood on the kicker and it didn't budge. I used a wrench to turn the motor over once then used the kicker to start it up. Wonder why that is?

Thanks for everybody's help!