[Darren69]

Originally Posted by Darkness

Take a look at the head castings on the left of the cam bearing cap. If it says V2 it is one of the big valve engines which is the same as the SS. These were used as standard from ‘93 to about ‘96.

When the M750 was introduced they put their small valve head and cams on the M900 as well. The heads of these are marked W.

V2 heads came back with the M900s and the injection models.

What he said. The SS and Monster engines are essentially the same with the above exceptions, 750 head 900 monsters were about 10bhp down on the S versions for a few years (would have to look up the years) which had the normal V2 heads.

Maybe yours has been breathed on a bit; hi comp pistons, head work or maybe it is the non-standard exhaust manifold? A good exhaust will let the engine perform loads better than the standard restrictive 40mm header version. 45 or 50mm headers with a tuned length (spaghetti system) and big 50mm link pipes and open cans is the way to go.