PRM-90 Problem

[Obi Wan]

I purchased my PRM-90 and installed it back in April (on a Universal Atomic 24hp). It only has 15 hours on it. A few weekends ago, I backed my sailboat out of the slip as normal, then headed out in forward. The next time I put it in reverse about 10 minutes later, it killed the engine. I thought maybe I had wrapped a rope around the prop, so I dove under but it was clear. I put it back in neutral (which was difficult) and started it again. It worked fine in forward, but when I put it back in reverse, it killed the engine again. It is obviously locking up somehow when placed in reverse and it is difficult to get it out of reverse when it locks up. The fluid is fine. This is a serious issue and shouldn't be occurring on a new transmission!

I have tried several times to contact PRM via the email on their website but they have not responded (though they had responded to this form of contact previously for another question I had so I know the address is good).

Has anyone else had this happen to them? Any ideas?

[Diesel Bill]

Sounds like fwd gear is staying engaged while going into reverse or some component in the reverse gear is locking up the shaft killing the engine. I've seen parts of internal shift
linkages (band strut) actually fall off the adjustment screw and rattle around inside the transmission. Sound like a warranty claim. Good luck with it and let us know what it was .

[Obi Wan]

PRM did honor this as a warranty claim and sent me a replacement. I have been very busy since receiving it and only recently got around to the replacement.
However, I had this replacement transmission in for only a few hours of operation, AND THE EXACT SAME THING HAPPENED AGAIN!
While in reverse, at relatively high rpm, the transmission seized, killing the engine. From that point on, reverse, once again, was completely seized, and only kills the engine when placed there.
What are the chances of this happening twice in a row unless their transmissions are substandard/faulty?
The installation is fairly straight forward and I spent quite some time ensuring the engine was aligned with the shaft. There can be no installation issues causing this that I can see.
My major problem now, besides buying a product that has twice proven defective, is that I cut one inch off my prop shaft to accommodate the PRM's larger dimensions. Now it will cost me considerably to go back to the original (but at least, apparently more reliable) Hurth transmission, including a new shaft and the considerable time and cost to haul the boat out of the water to replace the shaft.

[kmacdonald]

What kind of drive plate are you using? There are some with known problems with low HP engines not providing enough damping.

[Obi Wan]

Don't remember the name off the top of my head but it was a brand new replacement of the original of German manufacture.