Carb 4 does not want to fill with fuel

[Chris Cochran]

Subject: Carb 4 not filling
Ok, today I put fuel in the fresh carbs (not in the bike) and carb 1 leaked like the Titanic. The gasket had moved out of place. Easy fix. But, when I drained the carbs, 1, 2, and 3 drained about what I would expect, but #4 was bone dry. Opened it up, rechecked the float height and cleaned out where the float valve is supposed to seat with a Q-tip and some SeaFoam. They proved to be clean. Re-assembled and tried again filling. This time "some" gas did drain out but not nearly as much as it should be. This is irritating. I am out of carb cleaner spray so I guess I'll have to make a trip in a few minutes. The only thing I can think of to do is push the red spray tip of the carb cleaner into the tube that feeds the float valve and let-er-rip. The other three carbs seem good to go.

[cushman eagle]

Chris,you might want to remove the float and valve,then blow backwards through the float valve seat.
If there is a chunk of dirt in there too large to flow forwards through the valve,you could probably blow it backwards
I have found that to work on poorly maintained gas tractors.

[Chris Cochran]

I've used the "blowback" method before on my 750 carbs also.

I sprayed some carb cleaner in there and shot a bit of compressed air in. Now NONE of the carbs want to fill.

Today I achieved a Voyager Owner's Milestone: I have finally started cussing in no uncertain terms!

I have walked away from it for the next couple of hours. Time to get some food in me, sit and relax, then get back to it. I may have to start all over again.

[Chris Cochran]

I sprayed a liberal amount of carb cleaner in the tubes and the plastic fuel intake tube, then shot some compressed air from assorted, meaning all, associated openings, backwards and forwards, then gave it a try to see if anything changed.

The result of this was that carbs #1, #2, and #3 flowed normally again and #4 was improved a lot, but still not to the point of the others.

My next effort will be to swap the floats and float valves between #3 and #4 and see if the problem follows the change. If it doesn't, then the problem must be in carb #4's tubing.

If the problem does follow the change, then I'll return just the float valves back but leave the floats where they are. This way should determine if the float is possessed or if the float valve is. The problem will either stay with the float, or stay with the float valve, or, hopefully, go away.

Or, so goes the theory, anyway.

[Chris Cochran]

The past several days have been filled with family affairs, none wanted, but that's life. Even today I only had enough time to do a fast check on things.

I had swapped the carb 3 and carb 4 floats and float valves to see if the problem followed the floats. But I did not yet have time to put gas in them to check. So today I put gas in them and here are the results. Note: all floats set at 17mm.

When draining carbs 1 thru 3 each carb took me to the count of 25 before the drain stream petered out. Of course, each screw was unscrewed to the same degree for each carb. Carb 4 petered out after a count of only 10. The "strength" of each stream seemed the same, just #4 didn't have as much.

This is a ton better than nothing coming out at the beginning of this adventure but again only half the amount of the other three carbs. So, the problem did not follow the float/float valve into carb 3, but stayed with carb 4. This leads me to believe there is something stuck, STILL, in carb 4's fuel fill passage.

Last week, I had poured a mixture of Berryman's cleaner and SeaFoam in the fuel fill passages, flushed it out with water, and air blasted the snot out of it.

The only thing I can think of now is to inject pure Berryman's cleaner into the black plastic fuel fill-point and rest the carbs up at an angle where it all runs down to carb 4 to soak for a while. Then air blast it again. But this also means dis-assembling the whole bottom half for them all so as not to damage anything when the air shoots through. I've already had this thing apart four times already and this is now old.

Any other thoughts?

[Nails]

When draining carbs 1 thru 3 each carb took me to the count of 25 before the drain stream petered out.

I'd measure the volume of fuel. Better yet, put very flexible clear plastic tubing on the drain and hold it up beside the carb to see where the fuel level actually is.

There's very little clearance around the floats. They can get stuck, especially on gasket seal. (You only want to use about "none" to about "almost none" -- use sealant only if you really need to hold an o-ring in place.)