anybody know whether 1600sss/180bsss or SP311 1500/1600 twincarb rebuild kits are better suited for a12t hitachi carbs??? from pictures i've seen the needles are different lengths??? thanks

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yeah cheers I've read that one during my search, it mentions both 510sss and sp311 roadsters. Just wanting to know if one is better than the other. Gaskets are the same but needles different (never had anything to do with hitachi's as you may guess from my newbie questions!!)

Most rebuild kits don't come with needles. Just a needle & seat assembly and a couple of gaskets. If you get one with needles, none of them will be correct for the A12T, unless you get A12T rebuild kit.

The 510 SSS (1600 SSS or 1800 SSS) uses HJL38W
311 1600 uses HJB38W
311 2000 uses HJG46W

None of these are flattops.

so are you saying that none of these will work with flat tops?? from what i've read i was under the impression they were basically the same inside??

No, not saying that.

Question: flat top hitachi rebuild kits... anybody know whether 1600sss ... or SP311 twincarb rebuild kits are better suited for a12t hitachi carbs?

Answer: Neither 311 nor 510 (1600) twin carbs are flat tops.

Answer 2: I would guess the 180B (1800) kit would be closest as it is probably flat top type. But don't use the needles that come with the kit unless yours are damaged. Just use the needles you already have.

Hmm the Hitachi sidedrafts use the same fuel inlet needle & seat as the Hitachi downdraft.

So no special repair kit is needed. You can use regular needle & seat and make your own fuel bowl gasket (or just reuse the original), it is a very simple design. The gasket holds no vacuum.

None of these parts normally wear out:




The needle/seat sometimes need replacing, but rarely. The gaskets usually can be reused.

oh right, i see what you mean now. Thanks for that guys, that should help me sort them out. Cheers

or just go stright lpg like me and dont need needles and seats, just the piston to rise and fall.