XS1 won't start, sounds like a gun shot

[vorhese]

I need some help diagnosing this 1970 XS1 I'm trying to resurrect

Rebuilt Solex carbs, bigger jets (ditched rotten air box)
45 pilot, 140 main, 1 turn out on mix screw
Did cam chain, valves (xs1 spec), head torqued, new plugs, got bright spark
Only points/condensor/plugs hooked up, stator/rotor not hooked up
Running off fully charged battery.
No throttle cables hooked up yet, want to get it to idle first.
I have not messed with the points, saw good spark, didn't bother.
It sounds like a gun shot, one side at a time, per kick.
Ideas?

VIDEO

 

[DogBunny]

My money is on the following:
No matter how careful you are, it is very easy to get the sparking of the two cylinders reversed. I have done it, and so have plenty of others. It takes about two seconds to test. Either swap the plug wires or swap the points wires at the connectors, then try to start your bike.

 

[DogBunny]

The other possibility is that you aren't really getting fuel to the cylinders. Squirt 1/2 teaspoon of gas directly into each spark plug hole.

What about air? Back the idle stop screws all the way out, then back in till they just make contact with the stop screw, then further in for another 3 full turns. That will really let the air in, and it will rev really fast if it starts, so be prepared to quickly back the stops back out again.

 

[vorhese]

Swapped plug wires, started right up! HOLY CRAP love it. Thanks once again

 

[DaveO]

Not going to guess cos it could be anything or a combination of things. If it were me though I'd hook up the tank and the throttle. Mine likes the throttle to be slightly cracked. Also mine wouldn't start last week when I filled the tank after a long time empty of fuel. It ran fine the next morning (first kick) so I guess it was maybe a fuel airlock. This could be your problem.

Top marks on the barbeque BTW. That's bigger than my house.

EDIT - Damn - too slow.

 

[DogBunny]

Next for you is to add baffles. Your bike will never run right without them. Read this:
http://www.xs650.com/forum/showthread.php?t=26822

 

[vorhese]

I 100% agree, I actually yanked out the originals as they were crusty. I run a BUB Exhaust on my '80, and I really like it. Very high quality. I also have an old pair of cones.

 

[vorhese]

Here's another question. Changed the oil. It was horrible. The filter had sealant from the former head job. Anyway, the filter is moreless the same as my later model XS, but it had a black gasket behind it. Also on the new filter there are 2 little holes by the big hole, and none on the old one/ MikesXS says the same filters are used on all models. Do I need that gasket?

 

[vorhese]

http://www.ebay.com/itm/NOS-Yamaha-Oil-Pump-Gasket-256-13445-00-00-XS1-A246-/270659541073

 

[DogBunny]

It's not a filter, it's a reusable screen that lasts forever. Clean it at every oil change. The oil change interval is 1,000 miles. I said 1,000 miles. That's the factory spec. It's an air-cooled engine that cooks the oil and there is no true filter to clean that cooked oil.
Yes you need the gasket. The color of the gasket doesn't matter. It should last through several oil changes, maybe dozens, maybe more.
You also need the round gasket for the cover. Explore this site:
http://www.biker.net/650parts_index.html
and find the exploded drawings for your year, find the drawing with the screen, and find the round cover gasket that you need. It should also last through many oil changes.