chris walrod

Robin, this is one downside to a single ended fuel system (no return, regulated in the tank) is that there isnt constant fuel flow to help cool the rail (and keep cooler fuel flowing). I still think its a heat soak issue with the fuel.

Not related, I am back in Ginza now after two days testing in Sendai Japan. Just chillin' in the hotel overlooking a nice view of Ginza at midnight.

NC TRACKRAT

I'm going to put on my "old" hat here to recall my bought new '66 912 that developed the same problem after only a few years of ownership. Solved by adding the starter relay trick mentioned above. It was all related to heat soak contributing to high resistance. Suggest you run a test when it occurs by using a freon spray with an extension tube on the nozzle in the direction of the starter (NOT water!) to cool it down. If that allows it to start, then you have a starter going bad as mentioned above.

Robin 993DX

Chris, I am jealous, I would trade position with you any day of the week. I love Japan, especially Ginza.

NC TRACRAT - There are no starter issues as the cranking speed of the motor is the same cold or hot.