onedownfourup

Bike won’t hold an idle. You can hear it try to start; it wants it. Yesterday my neighbor (a car mechanic & motorcycle rider) had it holding for about two seconds before it’d give out.

I know the ignition is set up correctly, new coils with great spark, new PAMCO electronic ignition with proper wiring. I haven’t checked compression, but the kickstart clearly has some. As far as fuel, tank is completely clean thanks to tips from the folks at onedownfourup. I cleaned out the airbox & replaced the filter. Carbs are clean with all new kits, including gaskets, O-rings, floats, jets & needles. Fuel is flowing fine from the tank. I drained the float bowl on carb #4 & got nothing but clean gas out of it.

Some things I can think of that may be issues (brainstormin’):

1) I didn’t clean & fully inspect the accelerator pump on carb #2. They’re a bitch to fully clean. So I opted to just spray a good amount of carb cleaner down into the ball valve. Still, I don’t think this would keep the bike from starting, just give it throttle issues.

2) Maybe the accelerator pump is clean, but not set up correctly?

3) Air screws are incorrect. I tried playing with them after originally setting them 1.5 turns out of their seats. My neighbor recommended trying .5 & even .25 turns out instead. I never tried anything greater than 1.5 turns out though.

4) Maybe float levels are incorrect? I can’t remember if I set them to 14.5 or 12.5 mm – the shop manual suggested one while the Clymer manual suggested the other. It’s one of the two though, so I doubt this is the issue.

5) Maybe the slides in the carbs are not set at the right height. I didn’t base their height on anything other than eyeing a photo of another set online. There not completely closed, but they’re not far from it.

6) Felt washers in the carbs got melted off by the carb dip. Not sure if this would have that much of a difference; seems like some guys on the forum believe it’s a huge deal while others have run bikes easily without them. If mine got fried, it’s going to be a pain to try to make my own (they are not available anywhere as far as I know).

7) Something has made a nest up in my exhaust. Several guys on the forum report having changed everything with fuel, compression, ignition, eventually going so far as to switch out motors, only to later find the problem was that some small creature had collected things into a nest & been living in the exhaust pipe while the bike had sat for so long… Clean out the nest & the bike starts right up.

8) Aftermarket exhaust. I bought repair kits with stock jetting. My bikes been changed to a 4 into 1 exhaust. Again, don’t think this would keep it from starting though.

Damn.