Help Diagnose my No-Start

Those carbs may have a strainer screen on the needle valves like mine. Spray backwards to clear it.
Steve

Modrummer wrote: Ok so I took the carbs off to do the clear tube float bowl test. I got the first carb perfectly set. Went to do the second carb and no fuel would come out of the drain plug??? Gas VERY slowly goes down the funnel and gas line I was using to feed the carb, but none came out of the drain. When I took of the float bowl again it was wet with gasoline in there (though definitely wasn't filling up all the way). The floats move freely and appear to be operating perfectly.
Thoughts?

The float valve might be stuck closed (pointed tip of the float needle stuck inside the seat orifice).

Clear tube test:



It's often possible to perform the clear tube test without the special tool by using a tube size that fits snugly into the drain hole.
Minimal leakage from where the tube is inserted doesn't invalidate the test.

Good Fortune!

Ok I am more confused than ever. UPDATE: Both carbs have been adjusted per the clear tube test. I managed to get the stripped pilot jet out and replace it with a new one. I cleaned the pilot circuit as well as I could and it seems to be functioning (can spray carb cleaner in one hole and it comes out the others). I have the pilot air screw turned two turns out from all the way in. I have a good strong spark. And yet, it still won't start. I can get it to sometimes POP (backfire) out the exhaust, but that's it. If I use starter fluid it will act like it's going to start for about half a second, and then die.

Ideas?

Coil leads switched? Sounds like it.
Steve

swest wrote: Coil leads switched? Sounds like it.
Steve

What does that mean? Sorry for my lack of knowledge.

Did the engine start and run before the recent carb rebuild?

Good Fortune!

Patton wrote: Did the engine start and run before the recent carb rebuild?

Good Fortune!

The engine never idled, but i was able to get it to rev up and i could keep it running with the throttle. Bike had been sitting in a garage for almost 20 years previously. When i did get it to start (before i knew it needed a carb rebuild) the carbs overflowed and i believe some of the gas got into the engine. I drained the oil immediately after and replaced with new oil.

Is it possible that that did something to stop the motor from starting?

Modrummer wrote: Ok so I took the carbs off to do the clear tube float bowl test. I got the first carb perfectly set. Went to do the second carb and no fuel would come out of the drain plug??? Gas VERY slowly goes down the funnel and gas line I was using to feed the carb, but none came out of the drain. When I took of the float bowl again it was wet with gasoline in there (though definitely wasn't filling up all the way). The floats move freely and appear to be operating perfectly.

Thoughts?

Would assure that the float isn't installed upside down (if that would even be possible in this model carb).

The float tang may require adjustment (i.e., set float height) in order to allow the float valve to remain open until the correct fuel level is reached.

Good Fortune!

Starter system (enrichener circuit) might be clogged, resulting in non-functioning choke.









Good Fortune!

Patton wrote: Starter system (enrichener circuit) might be clogged, resulting in non-functioning choke.

Good Fortune!

Ok I cleaned the choke circuit as described and still no go.

I did notice something though, one of my pilot air screws is seated much deeper than the other (pictured below) even though they are both set 2 turns out. How is this possible? And could this be my no-start problem?

Also, could my ignition timing prevent the bike from starting, even though I'm getting strong spark at the plugs?

Have you compared the two screws? Timing would prevent starting.
Steve

swest wrote: Have you compared the two screws? Timing would prevent starting.
Steve

The two screws are identical (they came in the K&L rebuild kit)

Well now I'm gonna have to go mess around with the timing. I had to take the plate off to check the clutch (wasn't disengaging, ended up being stuck clutch plates) and I just put it back on in roughly the same position (took a picture) thinking I can fine tune it later. But maybe I didn't put it back right,

I'm assuming there is a guide somewhere on setting timing? I'll do a search for it tomorrow when I have time to work on the bike again if you don't have it off hand.

Thanks.