Topic: 3rd cylinder not firing

[Bastaldo]

Recently had the carbs redone and a top end rebuild. Been driving around for a couple of months and in the last two weeks the bike had been dying after 30 mins or so of solid riding, good in first and then bucking in 2nd. The hive mind thought it could be a fuel cap vent issue so I cleaned it out with a vinegar soak and then drilled it, and replaced the gasket.

Was just riding around and same thing happened. I limped the bike home and checked the cylinders with some spit and the 3rd was not boiling hot. I also drained the Bowles and they all were full except the 3rd, which had some drips (as opposed to the solid trickle).

The jets are all new so I don’t think they are clogged, so does anyone else have a thought? Could it be a stuck float?

[ekpent]

Yep it sounds like it could be a float that is jammed in the up position or the float needle stuckin the holder or its set way out of spec. Try the old hitting of the carb bowl trick with a screwdriver handle and see if it jars something loose.

[Bastaldo]

Great. I’ll see if I can knock it loose or poke at it.  Can a float be fixed without removing the whole rack?

[Bastaldo]

I dropped the bowl and there was still a little gas at the bottom and the float isn’t stuck. Could be that banging my hand against it 1,000 times while unscrewing it knocked it loose.

Since the bowl is dropped, anything else I can/should check when I’m down there. Should I stick my carb wire into the jets, just in case there is something?

[ekpent]

While your down there and doing Cals suggestions also make sure your bowl overflow and other vents are clear and not blocked including the rubber hoses.

[Bastaldo]

Ok- just a little trickle coming off the end of the carb when the bowl is dropped. Pushing the float up does nothing. I kicked it for good measure to see if that increased the flow, but it didn’t (the tried it with the ignition on and got it going on for a sec).

I stuck some carb stick things into the jets and nothing came out (they are all new- only a couple months old).

Is it fair to say it’s not getting the fuel from the fuel line? It’s a single petcock that runs into a filter and then breaks into two hoses with a wishbone before hitting the carbs. Wouldn’t the 4 carb also not be getting fuel? Maybe I missed that but I thought the pipes were hot.

[robvangulik]

Pushing the float up does nothing when there isn't any fuel flowing, obviously.
It reads as if the siff behind the float needle assy is dirty

[Bastaldo]

Oh yea- duh....

I think I can pull the needle out of the carbs as is- probably just worth cleaning that at the moment, or is it something behind the needle that will necessitate pulling all the carbs off?

Thanks Cal.

[robvangulik]

IF you can see what you're doing and IF your fingers are thin and nimble enough to pull out the float pin, needle and seat, you can leave the carbs in....