Re: spun prop, i don't think so
I may be nuts here but...I had a problem that sounded like yours with twin 150's. One engine would really rev high when I gave her some juice. I could settle it down by slowly applying the throttle. I had the lower unit torn down, the props checked out fine...turned out that when I installed the transducer for the fishfinder I set it too low and it was creating a ventilation issue. I rose the transducer and guess what, no more problem! Sometimes the simple stuff is the hardest to find!<br />Good Luck
I may be nuts here but...I had a problem that sounded like yours with twin 150's. One engine would really rev high when I gave her some juice. I could settle it down by slowly applying the throttle. I had the lower unit torn down, the props checked out fine...turned out that when I installed the transducer for the fishfinder I set it too low and it was creating a ventilation issue. I rose the transducer and guess what, no more problem! Sometimes the simple stuff is the hardest to find!<br />Good Luck