Novak issues

[Carver86]

Hi all
I've got a novak gtb with 5.5r motor fitted in my b44 and i got a few issues with it that I can't seem to solve, was wondering if anyone could help

1.The motor seems to intermittently cut out and will only start when it is turned on and off again. This has only started happening recently. I think it could be a sensor wire issue, can these be changed or does the whole motor need replacing? Is there anything else it could be?

2. When the motor did work i struggled to finish a 5 minute run as the speedo kept thermalling even though i drove it really smoothly. I managed to blow the speedo up today and fitted a spare but still have the same problem. The car is geared correctlyish and there is plenty of air flow so i can't work out what the problem is! Any ideas?

Cheers in advance