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What's the deal with the Mikuni carb slide needle seat?

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Hey everybody. Long time listener, first time caller.

So finally going over the carb of a new-to-me '03 S, and I think I'm missing that steel shim that sits at the lowest position of the needle assembly. BUT when I look into the bottom of the plastic slide I see a small tab/protrusion around about 1/8 of the hole the needle slides through.

Crude drawing for clarification:

4QDXRJU.png

Is this normal? It seems to skew the needle so it wants to sit at an angle if it weren't for the main jet/needle jet holding onto it. And even if I got that steel shim, again, it seems like it would sit cock-eyed down in the bore of the slide..

Any DRZ gurus know what I'm talking about and can reassure me it's as-intended? It runs fine for what it's worth, compensated for the missing washer with shims and clip position for now, just perplexed. I would think the whole needle assembly should sit flush and flat at the bottom there but I could maybe see a case where that "shelf" keeps any foreign debris from impacting the needle height and ruining your day in the field.

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You should have 1xthick washer,1x thin washer and 1x plastic spacer there.VERY CAREFULLY insert the needle assembly into the plastic housing-it must fit in straight until you barely hear a click,needle nose pliers work best.Also my washers dont have tabs on them,this tells me that you probably have the wrong washer there.The posts that i have read says it is very important to have these washers on the Mikuni Bsr36.

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There is usually a "D" shaped washer or plastic shim that goes under the clip and fits that tab in the slide so the needle sits flat. Yours is missing or it's made a bit different than the cv carbs I'm thinking .

You should have #8 and #9 , http://www.partzilla.com/parts/search/Suzuki/Motorcycle/2006/DR-Z400S/CARBURETOR/parts.html

I believe #8 will be the D shaped one .

 

 

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Edited by jjktmrider

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neither of mine was d shaped.....

 

but the needle doesn't sit flat in there, well, I had to manually line it up into the hole below

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So it took me awhile to get around to finally installing it, but I decided to OEM order the thick washer I seemed to be missing and the thin washer+plastic spacer just to check against what I had already. Spacer and thin washer were the same OEM parts. Threw the thick washer in first then the rest of the stack as usual.

Same comment as 74jimbo, little tab built into the slide causes the needle to skew ever so slightly, no D-shape on the washers or spacers when ordered direct from 'Zilla. But regardless, with that extra height put back in place via the thick washer, plus leaning out the needle clip position, the bike pulls from 0-100% like I felt it always should with the 3x3 mod.

That little tab still just seems...wrong, but everything is running well so good enough for me! Thanks for the input dudes.

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The molded tit in the slide is normal.  It is there on purpose so the needle sits sideways in the jet rather than flop around. Seems wrong but obviously Mikuni does not think so.  Keihin needles sit flat.  Difference of opinion.

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Possible I'm remembering CVK's with that D , don't know . Thought my Raptor660 carbs had a special shaped spacer under the needles , Mikuni BSR's . Probably to to stop the needle from jiggling and wearing out the emulsion tube then . They may as well have flat needles then with the taper on one side and the straight side against the carb , basically how it's being run . Lectron has that shape in their needles and use it as a main jet as well.

 

 

 

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Edited by jjktmrider

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