Modern Vespa

I've been riding my wife's GTV regularly, but this morning it would not start. It ran great just this weekend. Turning the key to ON and you can hear the fuel pump prime, 1/2 tank of fuel, battery stays on a trickle charger. The starter turns strongly, so not a battery problem. It just spins and spins but no starting. If it was a immobilizer problem, it would not even turn over, is this correct? Any ideas on where to start?

I had to ride my '66 VLB this morning, funny that the 56-year-old is more reliable.

Thanks

I'm pretty sure the starter will turn over the motor regardless of the state of the immobilizer. Have you checked the HT lead to the spark plug? Maybe it's something simple like that. Make sure it's tight on the spark plug. I believe you need to apply either front or rear brake for the engine to start too. Make sure the brake light is on when you try to start. This will tell you the brake light switch is working properly.

Kill switch?

Kill switch is on, won't even turn over if it's off. I'll go take a look at the spark plug lead. Seems so odd that it ran great Sunday, now this. I'm really suspicious about the immobilizer being the problem. Dead in the water in that case I guess.

I wiggled the cap a bit, and turned is slightly to get it fully under the little plastic retainer on the 300's, then it striated right up. Hard to believe that was it, but it must have been. This bike has only 955 miles, hard to believe little stuff like that is already acting up. Maybe I'll order a new cap and screw it on.

I'm really glad it wasn't the immobilizer!

Thanks for the replies!

I'm a fan of NGK caps, YMMV