Q: I have a Jonway scooter and I just cannot get it to start. The warrantee has expired so I'm trying to fix it myself. The engine has only done 7,560km. I've checked all the hoses and cleaned out the carb, fitted a new fuel and air filter and the automatic choke seems to be working because I connected it to a battery and saw it move, as recommended. I've also fitted a new spark plug. Any ideas before I kill myself?

Grim Reefer

A: Check the inlet manifold rubber to see if it's perished, but I doubt it with only that mileage on the bike. So I would say you have tight tappets, which is very common on these types of air-cooled engines. So take off the body panels and then the tappet cover, turn over the engine until one valve goes down and check the other for free play. If not, back off the nut and give it some. Then do the other. I'm positive this will be the problem because we get it in my workshop a lot. Check your manual for the clearance gap or call Jonway (jonway.co.za) if you don't have one.

Q: My 2001 Kawasaki ZX-12 (with 72,000km on the clock) has a very annoying misfire and I just cannot seem to find the problem so I'm hoping you can help? I've cleaned and gone through everything I can think of but after hours of swearing in the garage the problem is still there.

If you could shed any light on where to look next I would be eternally grateful.

Colin

A: If you haven't changed your spark plugs, and I doubt you have one in particular, it will certainly be that. You see number four plug is just about impossible to get to without dropping the motor forward or making some kind of spanner to get under that 'up and over' box frame.

Most shops when servicing tend to change just three plugs and ignore that troublesome fourth because of the time consuming and frustrating work involved to get to it.

So I'd check that first and it might just be quicker to remove bolts and tilt the engine forward, as suggested in the manual!