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Stage 4 is the step to turn your motorcycle into a cannon. Of course everything from the Stage 3 kit but now with Big Bore kit from S&S consisting of cylinders and pistons and the hot 550 camshaft from S&S, combined with high lift valve springs.  

The kit is available for all M8 models, the 107 goes to 124 and the 114 and 117 models to 128 ci (2100 cc) with a compression of 11.1 to 1.

The kit comes with chain driven camshaft or sprockets each with its pros and cons. Also the choice of a torque or power camshaft and black or chrome push rod sleeves. There are also various options with the paint of the cylinders that perfectly suits your Harley.  

Included in the price are ARP studs for the rocker arms and a set of black reusable S&S head bolts. Larger injectors also go into the injection body.  The coupling with a TPP pressure group is also changed to handle the high power. New valve cover gaskets and oil and oil filter.

The costs of Stage 4 are 7500 euros.

(including assembly and adjustment and dyno proof)

I assume that there is already another muffler and air filter housing on it, otherwise I can also supply and install these.

This kit can also be combined with a special custom cam for an extra 400 euros.

This kit can also be combined with a Thundermax instead of Diag4Bike for 800 extra.  

The kit can also be expanded with machining the head with larger valves and seats.

Larger Throttle body, a Screaming Eagle head, call for the possibilities........

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