I have a 23 GDLT on a Go Devil 1838. I have always run 9x6 props, but when I ordered one from Backwater last week they were out and suggested I try a 9x7.

The motor will turn about 4300rpm out of the water. If I run the motor just like I always have it turns 3260rpm. If I push down on the handle until the cavitation plate is just at the surface I can turn 3500rpm.

Are my RPMs ok or do I need to go back to a 9x6? Or do I just need to weld a piece of flat bar on the back of the cavitation plate so I can trim the motor a little?

Also, this brand new prop only measures 8.5" in diameter. Does anyone have experience with how fast these wear out? Compared to other true 9" diameter props.

No change in speeds?


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If your speeds are the same I wouldn't worry too much about the low rpms are, though they should be a good bit higher. But yes, backwater props wear out faster than any other prop I have run.

I never checked the speeds before, but it does seem a little slower now. Hopefully trimming the motor will help a little. It feels alot faster when I run it with half the prop out of the water.