{"product_id":"mcs538405","title":"Compu-Fire, Ignition Module. Electronic Advance for Harley-Davidson 1970-1999 Big Twin (Excl. Twin Cam, Excl. Injection Models); 1971-2001 Sportster (Excl. 1200 S) - 21835","description":"\u003ch2\u003eDescription\u003c\/h2\u003e\n\u003cp\u003eFor electric start models only. Same as 538404 but with slower advance curves for high compression engines that struggle with detonation issues. Full advance is reached at a higher RPM. Comes with selectable single\/dual fire and\/or single\/dual plug. Selectable advance \u0026amp; RPM limiter. With 8 advance curves and 8 RPM limits; from 6000 up to 7500 RPM; it can be adjusted to fit your specific engine. Easy selection by a rotary switch on the ignition unit. All modules come with a built-in static timing light and feature a extended temperature and low voltage operation with soft-start circuitry for easy starting. Note: A tach adapter (MCS 538408) is required to correct tacho-output when using single fire ignition; for correct RPM representation.\u003c\/p\u003e\n\u003ch2\u003eFitment\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e70-99 Big Twin (Excl. Twin Cam, Excl. injection models)\u003c\/li\u003e\n\u003cli\u003e71-01 Sportster (Excl. 1200S) (NU)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eProduct Details\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Compu-Fire\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Electrical \u0026gt; Ignitions\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct code:\u003c\/strong\u003e 538405\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003ePart Numbers\u003c\/h2\u003e\u003cp\u003eMCS Part Number: 538405\u003cbr\u003eManufacturer Part Number: 21835\u003c\/p\u003e","brand":"Compufire","offers":[{"title":"Default Title","offer_id":57360649421187,"sku":"MCS538405","price":441.43,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1329\/4265\/files\/538405k.jpg?v=1775723362","url":"https:\/\/hogparts.co.uk\/products\/mcs538405","provider":"Hogparts UK Ltd","version":"1.0","type":"link"}