'75 HS Bing 54 will not idle

[lancestrahl]

I know there has been a fair amount of coverage of this type of issue on the forum, but there are still a few things I need cleared up.

The bike kicks over without an issue on the 3-4th kick and revs nicely, if a bit tinny. Problem is, it will not idle at all. It slowly revs down to where an idle would be, then keeps going down until it shuts off. I have tried adjusting the screws until I'm blue in the face but cant seem to find a spot at which it will idle.

I replaced all seals and gaskets on the carb, although there does seem to be gas still getting out of it somewhere as there is some gas pooling on top of the engine case.

Also what should the jets and needle be for this carb? I have read 3-4 different sizes for the same carb on POG, and before I order a new set, I want to make sure they are right.

Any help would be appreciated.

Thanks,
Lance

[Dale Sonnenschein]

Jetting depends on elevation. It sounds like it's lean by your description. And there is always the chance that the carb is worn out. Try going up with the pilot jet. It might take a few trys to get the right size. If you have a carb on another running bike, you can fit it on the penton and see how it runs. Last option would be a new carb.

[lancestrahl]

Sorry should have included that, I am at sea level.

[Daniel P. McEntee]

Make sure your pilot jet is open and not clogged. This is often overlooked. Make sure you can pass a thin wire through it. I use a welding torch tip cleaner or the correct size number drill to clean them out if varnished. If the pilot jet is clogged, it will not idle.

  Type at you later,
   Dan McEntee

[slvrbrdfxr]

Lance,
Welcome to the POG site. I'd recommend that before proceeding much farther, you do a leak down test on the engine to determine if there might be an air leak through a crankshaft seal or gasket. The smallest of air leaks can cause problems like what you're describing. Basically, you have to cap off the exhaust and intake then apply approx 6psi of air to see if the engine will hold that pressure. A good tight engine should not leak down more than 1psi in 5 minutes. If the pressure bleeds off quicker than 1psi in 5 minutes then you just use some soapy water solution to determine where the air is escaping. I've built a home-made tester using common plumbing connectors from Lowe's and a metal scrader valve from a local auto parts store. I use a hand bicycle pump to supply the air pressure. I'd be glad to send you pics of the tool I built if you contact me through the website.
Dave McCullough

[lancestrahl]

Thanks Dan, Dale, and Dave for your advice on this. I have pulled the carb back off the bike, and will be going through and checking and replacing jets and needles. While I have it off, I have wanted to take a look at the slide, as I had read on several other posts about slide wear. The reference I keep hearing is that if it has a "smiley face" it is time to replace it. I have no idea what this would actually look like, as I advent been able to find pictures of it.

I have uploaded several pictures of the slide, and hope you might be able to tell me if it has this "smiley face" and if it is time to replace it.









Thanks,
Lance

[Larry Perkins]

Yours has some wear but it is not bad.  It is still good to run.

Larry P

[lancestrahl]

Thanks Larry!