Originally Posted by
Eivind E
Piston/Sleeve/Rod - same part number
Crankshaft - same part number
So no, it's not "completely different".. Same engine, different bearings.
Seems like you had some mighty big placebo.
Bearings and case not same, only That makes a huge difference! but again, you talk about the btt, fine with me, but you never tried the keep off 4, so in fact you can not really compare the two....

Why on earth do you think That nova made the keep off 4 if it is not any different from the btt, just for the fun of having two same engines with a different name?