Is there a way to check if a center seal is bad on a 175

[rwgibbon]

Larry Young has been trying to get a BS 175 running. He can get both side running and then then right side cuts out and
stops running. He has replaced the points, condensers, and even the coils. He checked the compression against his BS 175
rider and it is the same. He has tried swapping carbs with the same results. It will run on both sides for about a minute then
the right side will cut out and not run. If he lets it cool down it will start up again but will quit after it warms back up.

He has even replaced the wiring harness.

Is there a way to check if the center seal is leaking?

Thank you for your advice.

Randy

[AlanJohn]

l know this sounds stupid but has he checked the fuel tank cap vent l had this problem on one of my 350s and it was that simple new cap from Richard never had a problem since and the symptoms were exactly the same as your describing

[OldSwartout]

I bought a 175, couldn't kickstart it, did a leakdown test by plugging the exhaust and intake. When one cylinder was pressurized, you could hear air leaking from the other side. That center seal was torn really badly, but even it would run AND idle once you got it running by push starting it fast, so the normal stiff seal or slight leak wouldn't cause it to stop once it was running.

[rdwilroy]

Had the same symptoms with another twin I owned. Turned out I had a dirtdobber build a nest in one of the carb vents. Finally realized it after taking the carb off about half a dozen times.