Idle problem.

Thank you all for the help you have given me so far, I really appreciate it. Hopefully this is the last problem I will have. 8)

Last fall I got my bike. Removed the carbs, cleaned them, and rejetted for pods (the po broke the air box in a drop and I did not want to pull the motor to replace it) Reinstalled the carbs and she fired right up and idled like a dream at a little over 1100 rpms. The gas tank had a leak and since it was getting colder I decided not to worry about the bike again till spring. I drained the carbs and put the bike in the back of the garage till spring.

Well spring is here and I got the bike out. I fixed the gas tank, put in a new charged battery and fired up the bike. It ran and idled just like it did before I put it up for the winter. I went about fixing up the problems with the bike, rewired fuse box, changed oil/ filter, new plugs, added fuel filter, rebuilt petcock, cleaned starter clutch, and so on.

The problem that came up during this time is that the bike has quit idling. It will run fine with the enrichment circuit engaged, but turn it off and the rpms drop and it dies. As soon as the rpms get below 2k they drop off and it sputters and dies. I can turn the idle control screw (between the #2 and 3 carb) all the way in and it makes no difference. It is like it is not even turning the blades, but it is. Turn off the enrichment circuit and it dies.

I took the carbs back off the bike and they are still clean inside. The little passage in the front of the bowls is still clean as a whistle and shoots a beautiful spray of carb cleaner out it when sprayed into. The carbs are all still synced up like they where after I bench synced them in the fall. The little tube that goes into the well in the front of the bowl is clear.

This thing has me beyond perplexed and I am hoping some one here can shed some light on my problem and point me to a fix for it. Thank you for all your help so far and thank you for taking time to read this. Sorry for the long post, I am just trying to give as much info as possible.

 

Good luck on this being your last problem

Anyway did you check the pilot jets carefully? Haw about float levels?

 

Yup, the pilots are clean and the float level is where I have read it is to be. The weird thing is, when the problem started I had not even touched the carbs since the initial clean and sync. And they worked fine one day, then the next the would not idle.

 

Try it with the petcock on prime. I see you rebuilt it and possible that maybe somehow there is a related issue? On prime it should just flow.

 

I thought that at first as well, so I gave it a try. The filter stays full and the bike still dies as soon as the enrichment circuit is clicked off. If I give it throttle it will stay running. When I replaced the vacuum line, I did leave it longer than it was originally. Wonder if that could be a problem, not enough vacuum at idle to force fuel into the carbs, because of the longer line? Hmmm......

 

But the pri would have taken care of that. Additionally, the longer line would not lower the vacuum unless it is collapsing or kinked.

Something in the idle circuit of the carbs not allowing fuel flow. (Since you verified that cranking the idle speed screw open the flys that control air, then it is not getting enough fuel...

...or wait perhaps your loosing spark below that speed do to the charging system not being strong enough? How's the battery?

 

Perhaps you got some c--p in the beanie filters when you have messed with the tank & petcock.

 

Batt is new and has a full charge. Plus after long cranking times I have put it back on the charger.

Where are the beanie filters? I'll check them out.

 

Under the float needle seat.