Rubber Diapraghm on Keikin CVK 24mm

[jbcinzio]

Hey guys.

Finally got time to install my new Keihin CVK 24mm Carb in the Like 50 4T!

Well.... sort of.

Everything bolted up better than I thought, with the new carb even fitting into the original inlet hose from the airbox.

The problem is, that I left a sneaky vacuum hose off the manifold (didn't see it hiding!), and proceeded to try and start the scoot.
After 20 minutes of cranking and pouring fuel manually into the bucket, I gave up for the night.

The next day I tried again. I eventually found the elusive vacuum line and connected it, and pulled the top off the carb to pour some fuel in.

When I went to put the slide back in the bucket, I noticed that the rubber diaphragm had stretched so that it won't fit into the groove correctly, and threfore won't provide a good enough seal for vacuum.

WTF? I thought thhis type of rubber would be fuel-proof....

Any ideas?

Josh.

[sidthesloth]

I recently heard of boiling o~rings in water to shrink them back to original size, I don't know if that would work with a diaphragm.
Otherwise persevere and try to get it back into the groove, with patience, you might get it. Good luck.

[mrbios]

Just adding a solution even though this is an old post.

You can brush or apply grease into the groove that the diaphragm sits in to seal things back up.  Depending on how much is got messed up you might need to put a weight on part of the diaphragm and apply rtv a section at a time.

[wheelsoffreedom76]

   When your carb is empty, best to disconnect the vacuum line for the vacuum operated fuel valve and suck on it for around 10 seconds. This will allow fuel to refill the carb bowl. No mess, flooding, or damaged carb parts.

[mrbios]

   When your carb is empty, best to disconnect the vacuum line for the vacuum operated fuel valve and suck on it for around 10 seconds. This will allow fuel to refill the carb bowl. No mess, flooding, or damaged carb parts.

Great tip thanks!  I'm hoping to put together a how to for the GV 250 to troubleshoot and clean the carb I will be sure to include this and footnote the reference.

Paul