High-Speed FZ Needle Seat for Carburettor YSF1555 by YS Engine  [YSF1555]

YS ENGINE HIGH SPEED NEEDLE SEAT FZ #F1555
Price:
£4.39
Brand:
YS Engine
Model:
YSF1555
GTIN:
4560105735703
Condition:
Brand New
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High-rpm needle seating details

The YS Engine YSF1555 FZ high-speed needle seat improves repeatability of the high-speed needle to deliver stable high-rpm performance in glow-engine carburettors. The FZ designation describes the seat profile used at higher engine speeds.

For fitment, remove the carburettor bowl, withdraw the needle assembly and replace the seat using standard hand tools. Clean the threads thoroughly and align parts to avoid cross-threading; light lubrication on the needle shank can aid smooth travel.

Although not a tuning item by itself, the seat condition has a direct effect on how repeatable high-speed needle adjustments will be. Regular inspection, cleaning and confirmation of free needle travel after assembly will help preserve consistent top-end behaviour.

Is the YSF1555 compatible with non-FZ needle geometries?

The seat is specified as FZ style and is intended for use with FZ high-speed needles. Compatibility with other geometries is not guaranteed and depends on the needle profile and carburettor design.

Will fitting this seat alter needle travel or response?

When correctly fitted, the seat does not change travel range but provides a stable seating surface that improves response consistency and repeatability at high rpm.

Any tuning tips to maintain consistent top-end after replacement?

After replacing the seat, re-establish your baseline high-speed needle setting and run incremental adjustments. Verify consistency across several runs and check for any external factors such as air leaks or fuel quality that affect top-end behaviour.

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