Cheeky-Thomas
INDEPENDENT VESPA SPECIALIST
Valve Clearances.
Another simple task that not mahy people do, and from experience a lot of dealers only claim to do but dont actually bother, but with these instructions youll see it only takes 30mins max and can save thousands in engine damage.
Right then we start with the machine in question.. this ones a 300 but they are all the same, so lets get into it.
Obviously the first steo is to open the seat and remove the seat tub so we can see the engine itself...
So we can now see the rocker cover with the breather pipe attached, youll need to remove this and just tuck it aside out of the way, the original clamp is a single use item and a bit fiddly to remove, just bin it when done, a cable tie is much easier to use.
Now we need to start removing the 5 bolts that hold the cover into place, make sure the rubber seal comes with them. The top ones are easy to get too, the lower ones are easier if you put your hand in from underneath unless you have skinny arms.
Some people undo the shock mounts on the rear allowing the engine to drop slightly as it gives a little more room, i dont find i need to, but the choice is yours.
So thats the 5 bolts out and the cover can now be allowed to drop down into the space below, it wont fully come out but you have the room to do the clearances then just put it back in place.
Now we need to get the engine on its timing marks, if you have the belt cover off you can turn the crank by hand, if not remove the sparkplug cap and use the starter in short bursts.
Theres an inspection window on the RH side engine case, its a large torx bit to remove it, inside you can see the rotor and its markings...
This is the timing mark on its point, the case has an moulded marking and the rotor has a line marked with a T and the 2 need to line up...
Once the bottom mark is lined up now look at the camshaft pulley and you see its on its timing mark, youll see it has 2 arrows, 2v and 4v depending on the engine, it refers to how many valves the engine has and you can count that to be sure... this engines a 4v so make sure the arrow is lined up to the casting on the head straight upwards.
So now the covers out of the way, the engines on its timing marks so we are ready to adjust the clearances. Top ones are inlet and bottom are exhaust. We need a 8mm spanner for the lock nuts and a slotted tool to move the adjuster, and of course a set of feeler gauges,
The process is simple, undo the lock nut, wind the adjuster out, insert the feeler gauge and then tighten the adjuster up until it gives a slight pressure to the feeler gauge, then hold it there and tighten the lock nut down. Do the same to all valves.
Aim to get 0.10mm for the inlets, and 0.15mm for exhausts.
Put the cover back on, put the bolts back in, not forgetting the rubber seals. Then reconnect the breather pipe and secure with a cable tie and jobs done.