Air Cut Off Valve. How to tell if it's bad.

5 replies to this topic
  • carfan87

Posted January 20, 2008 - 08:31 AM


I have a 1996 XR400 and after pulling the carb apart I noticed the air cut off valve is a bit stiff and if I hold it up to the sun I can see a number of VERY small holes in it. How can I tell if I should replace it? Is a Honda dealer the only place to get one as they are $40 from them.


  • Trailryder42

Posted January 20, 2008 - 07:15 PM


Doesn't sound good. Is the bike backfiring on decel?

Do you have to stretch the rubber to see the holes or do you see them without stretching it? If stretching it and the holes close up when released and the bike runs ok as is, I'd let it go.

  • carfan87

Posted January 21, 2008 - 04:50 AM


It did not seem to backfire on decel but I've not had the bike for that long. It was hard to start though. The holes are there without stretching. I'd say the rubber is more like cardboard than rubber so it's not going to stretch much. It's sounding lik it's probably bad to me. Is Honda the only place to get it?

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  • Trailryder42

Posted January 21, 2008 - 11:08 AM


Sounds bad to me too. There are a couple of places to get Honda OEM parts. They're all about the same price from what I can see. You get the whole assembly, not just the rubber diaphram. You might call and see if the diaphram is available by itself.

  • ganshert

Posted January 21, 2008 - 12:26 PM


I've found these guys to be the cheapest source of OEM Honda stuff and they have great customer service.

  • Trailryder42

Posted January 21, 2008 - 12:33 PM


Yeah, they seem to be the cheapest yet, $36.

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