WR400 AP Diaphragm, Which one should I order?

3 replies to this topic
  • chickenstrips

Posted May 19, 2008 - 09:09 PM


Need to get a new AP diaphragm for my carb and I am wondering if I should order the stock one or one of the "optional" stock ones.

Stock one is

I believe there is also:
5BE-14940-17-00 (optional)
5BE-14940-19-00 (optional)

From what I have searched for I see that they have varying lengths of studs on the AP diaphragms to increase of decrease the squirt duration, but I didn't find anything stating if one was really better than the other. A longer squirt duration would help with the off idle bog and rapid throttle openings wouldn't it? I am not even sure which part # is the longer squirt one. Thanks.

  • Solo

Posted May 20, 2008 - 09:19 AM


I put the standard one in mine when I replaced it. Use caution going with a longer squirt as it can cause as much trouble as a short squirt. If you did the BK mod which allows you to tune the length of the squirt then I'd say get the one that generates the largest squirt.

You might also try asking in the Jetting forum to see if you can get some more info.

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  • turbohead

Posted May 22, 2008 - 02:17 AM


Go for an Edelbrock carb instead. Adjustable pump, among other benefits.

  • chickenstrips

Posted May 22, 2008 - 07:52 AM


Go for an Edelbrock carb instead. Adjustable pump, among other benefits.

What? :thumbsup:

Pony up the extra $380 for me and I'll try it out. :ride:

I went ahead and ordered the standard one. I found out I can do the "taffy" mod.


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