as the MV is now road legal. So I’ve been out riding to find out what is good… and not so good.
First the good. It’s amazingly fast, extremely comfortable with fantastic brakes. At least compared to my Cyclemaster! It also generates quite a bit of interest – probably because it’s red and Italian, a bit like a Ferrari to the 4 wheel petrolheads.
But there are some less good aspects. First, it’s smoking a little but I’m hoping that’s because the motor is running in, after the new piston was fitted (eternal optimist at large). And the fueling is very poor. It won’t idle and seems to be running rich. It hesitates at full throttle and then picks up as the throttle is rolled back.
So it’s another carb strip to check the idle jet and pilot circuit. Everything looks fine apart from the pilot jet is very small at No.35. Such a small pilot jet is most often used on smaller engines around 125cc and research saws the early version of this engine was fitted with a No.45 jet. As luck would have it, the spare carb bought with the MV has a No.40 jet, so it’s worth a try. Good news, it now idles OK but still won’t rev out correctly, regardless of slide needle position.
A quick bit of research on the excellent Dellorto website uncovered the original carburettor settings and for some strange reason both the main jet and throttle needle are the wrong parts. The main jet should be 102 and a 109 is fitted; the needle should be E12 and an E10 is fitted. The E10 needle is much smaller at the pointed end and this is the cause of the rich mixture at large throttle openings – problem solved.
But not quite.
The engine now pulls and revs much better but the extra torque is making the clutch slip….
and the battery is not charging……
and the petrol taps drip…….
and the speedo reads wrong…….
and the sump plate is leaking a little oil……
and the cam box cover is leaking a little……
and finally (for now) there’s the cam shaft oil feed mod I want to do. The standard method is to drip oil onto the camshaft from a tube mounted above it but this isn’t very effective as the spinning cam shaft just throws the oil away, leading to premature camshaft wear and failure.
The better method is to feed the oil through the camshaft (like all modern OHC engines) and this is the mod I want to do – WHEN I FIGURE OUT HOW.