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Thread: Ear Shave
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post #3 of (permalink) Old 01-16-2006, 08:50 PM Thread Starter
Vulcan Verses
 
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You may read some posts about Sherm's rebuild kit that includes a replacement needle. Here's some posts from October 14, 2005 that may help answer the needle question:

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I'm ordering the parts separate from sudco.com per Jason's previous post. Jason never made reference to needles but I have seen other files where someone made reference to Sherms needle's #965h7- 44u7_ss, part of the Ear Shave kit.

Since I did not purchase Sherm's kit, do I need to change the stock needles? And if so, does anyone have the Sudco's PN that cross references with Sherm's PN#965h7-44u7_ss? I emailed Sherms but appartently they're no longer in business (or so the homepage says) and I have not gotten any responses from them.- Frank Braun
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Sudco doesn't have replacement needles for our carbs (maybe factory needles but not "shorter ones" for ear shaves). After the ear shave, the needles need to be shorter. As far as I can tell, no one makes a shorter needle for these carbs. The only way to shorten the needle is to add shims (obviously doesn't shorten it but raises it up a little). I put two under each needle and that seems to work fine. Two shims seems to be the standard that works for most people. -Jason
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Just to clarify -- I used 40s and 140s, but 4 shims ON "TOP OF" each needle, not under. -Pick
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The shims go under the "Head" of the needle (like the head of a nail). If someone said that they put a washer under a nail, it would most likely be understood that the nail went "through" the washer, not that the point of the nail was on top of the washer. The needle is tapered, and with more air flow from the ear shave, more fuel is needed to maintain the correct fuel to air mixture, so raising the needle opens more area around the needle to flow more fuel. I removed each needle, slid two spacers on, then put the needles back in. This puts the spacers on the top end on the needle but not on top of the needle. ??? I'm confused. What does putting spacers on top of the needle do?-doowriter123
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OK, I don't claim to know the whys and wherefores, but I got the ear shave kit from Sherm's before they went out of business. I got a selection of jets, shims, and new needles with the kit. I used 40 pilots and 140 mains, with the clip in the 3rd position on the new needles. IIRC, that was in the middle slot. I did not use any shims. The bike ran fine while accelerating, but when I let off the throttle, it would stumble badly -- sort of like it was running out of gas or something (maybe it was flooding?). I popped the tops off of the carbs and put 4 shims on top of each needle, and the stumbling disappeared. The bike ran great all the time, throughout the rpm range, accelerating or decelerating. I don't know why this worked for me. It didn't make any sense to me either. I thought the shims would have to go under the needles. I can only guess that putting the shims on top causes more pressure to be applied downward, keeping the needles from "floating" as much, or something like that. -Pick
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Sooooo.... You didn't use the original needles. You had needles that used clips that came with Sherms kit. The clip position limits the maximum down limit of the needle. This explains the 3rd clip position.

If the clip on the needle is enough smaller than the vacuum slide spring seat, the needle could possibly be able to wiggle around and up and down, so putting shims on top could hold the needles down where they should be.

The needles and clips are a more expensive way to get the result, but they may have been chosen because of their profile. -doowriter123
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That sounds plausible to me. The new needles came with the Factory Pro jet kit, so I thought I may as well use them. If I had stayed with the stock needles, I would most likely have used a different configuration to get it to run right. -Pick
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After the ear shave, the needles need to be shorter. As far as I can tell, no one makes a shorter needle for these carbs. The only way to shorten the needle is to add shims (obviously doesn't shorten it but raises it up a little). BOTTOM LINE- Use the stock needle, and two shims "UNDER" each needle. -Frank Braun

Last edited by Vulcan Verses; 01-16-2006 at 08:52 PM.
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