No gas getting through carbs

[Anonymous]

Retrex, thanks for your to-do list. I really am hoping to be able to isolate what the problem is before I just go hog-wild and tear the whole thing down again.

I did pull all four plugs. I had installed them new maybe 400miles ago. They still looked good- had a little black carbon and the gap was still the same. They all got a solid spark.

I'm not exactly sure what test you wanted me to do with the airbox. After connecting the airbox boots to the carbs, I left the side-panel off (but had the air-filter in) and sprayed starter fluid into the top of the airbox- pretty much right into the carb boots. Do you want me to pull the air filter and cover the hole inside the airbox with my hand, or the hole on the bottom of the airbox (on the outside, with the side cover back on)?

Thanks again!

[retrex]

Retrex, thanks for your to-do list.
Do you want me to pull the air filter and cover the hole inside the airbox with my hand, or the hole on the bottom of the airbox (on the outside, with the side cover back on)?

Thanks again!

Pull the airfilter and cover the hole inside the airbox with your hand. If you have linked up the cams correctly to the crankshaft then as the pistions are on the downward stroke with the exhuast valves shut, intakes open, the resulting vacuum will suction the gas from the floatbowls through the various passageways into the cylinders. What we are trying to do is make sure all the passage ways are primed with gas. Sometimes normal operating vacuum pressure is not enough to get the gas through dry passageways. If this works your engine should start and rev fairly high until you pull your hand back a bit from the opening. If this doesn't work, meaning your sparkplugs are still dry then we have to check the compression. You may have hooked up the crank and the cams so that on the above mentioned downward stroke the exhaust valve is not shut down as it should be, or possibly the intake valves aren't open as they should be. Your comment on it cranking much better than before the redo may indicate this. Anyway what this results in is little or no vacuum on airbox side, or not enough draw or pull on the dry passageway to suction up the gas. It could also be pushing air back out on the upward stroke through either/and/or exhaust and input valves. Hence no compression. Try the hand thing. It don't cost nuttin.

I won't be online today after 4:00PM EST until Monday morning. Hope things work out before then. Don't get discouraged. These bike want to work, we just have to let them.

[KEITH KRAUSE]

The vacuum line is smaller than the other (?) line, right? The larger hose connects to the "T" fitting between carbs #2 & #3, right? The smaller hose connects to a brass fitting on one of the carbs, right?

The smaller hose, the vacuum, goes to the brass nipple at carb #2 (as you sit on the bike.) Make sure the vacuum goes there or you'll have no fuel flow except on prime. The other two nipples are for the float bowl vent lines. Make sure they stay clear and route them so they don't kink.
Even if you do have the vacuum hooked up wrong, the bike should have gas in the cylinders from priming it.
Did you at least do a good bench synch? If the throttle plates are too closed from a poor synch, it'll never start. Also, did you re-set your mixture screws to their previous setting?
One more thing, if fuel is overflowing out the carb overflow lines, you have float valve needles that aren't sealing. The high fuel level in the bowls would hinder starting too.

[retrex]

Status update

So where are we with this j2x?