This is our racers favourite way of dealing with the worn or troublesome front primary gear bush.(this is NOT the top hat type rear bush)22.5mm wide. Racers and professional engine builders will use their own tolerances but these are set for road use.
PLEASE NOTE: This floating bush is not suitable for early Cooper S primary gears (which have a larger internal diamension), original A+ helical primary gears OR our own straight cut primary gears manufacturered before 2015. They are ok on Minispares manufactured helical gears and straight cut gears after 2015.
Ideal for use on the stepped type 1275cc type cranks this bush is fully floating and does not require the extra costs of fitting and machining. Always ensure that the bush buts up squarely to the shoulder with the oil holes in the trough and not on the edge of the stop step, as the oil drain holes can
act as cutting tips on the edge of the bush. Remove old bush and clean area with wet and dry, check the inner bush area is not machined on an angle by the oil hole as this will shred the new floating bush, this is how most A plus gears were machined. Remove old bush and clean area with wet and dry, stick in the new oiled bush and you are ready to go. Ensure crank is not worn or blemished.
Another product developed by Minispares technical department.
Front bush ID 1.628" +0.002" -0.0" never undersize as it requires clearance.
For race allow an extra thou 1.504" +0.001" only.
The ID of the gear 1.750", our bush measures at 1.748" +/-0.5 thou.
measurements 2024 are 44.40/44.38mm o/d and 41.375/41.34mm and 22.50m long