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Cavitation...Swapped TRS with Konrads

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Old 05-26-2023 | 11:36 PM
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Default Cavitation...Swapped TRS with Konrads

87 Chris craft stinger 390 X. Owner replaced

the original TRS drives with Konrad's and injected 540s. I'm assuming in the stock location. The boat comes out of the hole OK but appears to be cavitating until it is up on a plane. My initial thought is the drives are not far enough down in the water. Thoughts?
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Old 05-27-2023 | 06:33 AM
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Those appear to be Konrad HP’s, they’re just under 2” shorter than the
TRS, this may happen when getting on plane, it’s a trade off for better performance at top end.
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Old 05-27-2023 | 06:46 AM
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I once drove a boat that was doing it too. Complete different boat though... i was putting tabs down and /or turning left and right to rock the boat from side to side so the prop could bite more, not perfect but it was the way that helped!
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Old 05-27-2023 | 08:04 AM
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Get a set of these

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Old 05-27-2023 | 09:34 AM
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Originally Posted by JaayTeee
Those appear to be Konrad HP’s, they’re just under 2” shorter than the
TRS, this may happen when getting on plane, it’s a trade off for better performance at top end.
Oh I see. So I'm assuming with powerboats this would be considered normal? My first thought was it needs bigger props but I don't think they could be more than an inch and a half longer blades.
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Old 05-27-2023 | 09:36 AM
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Originally Posted by Craney
Get a set of these

Those look nice. Were you having the same issue?
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Old 05-27-2023 | 09:39 AM
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There is nothing wrong with a little cavi when getting on plane, mine break loose around 3500 just pull the sticks back a bit and they'll bite
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Old 05-27-2023 | 09:43 AM
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Well it's good to know it's normal. I've owned a bunch of boats but never a power boat so I've got a bit of a learning curve ahead. As a drag racer (bracket racing) we don't like slippage of any kind 😂
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Old 05-27-2023 | 12:04 PM
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My boat had the propshafts 3” below the bottom of the boat.

They key to getting it on plane was to not exceed 3200 rpm’s, if you did,
it would blow out and you would have to let off and let it get hooked back up, or start over, if you kept it below 3200 rpm, it came on plane every time.

You might want to try and figure out if you have a particular rpm on yours
where this occurs
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Old 05-27-2023 | 12:55 PM
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Originally Posted by JaayTeee
My boat had the propshafts 3” below the bottom of the boat.

They key to getting it on plane was to not exceed 3200 rpm’s, if you did,
it would blow out and you would have to let off and let it get hooked back up, or start over, if you kept it below 3200 rpm, it came on plane every time.

You might want to try and figure out if you have a particular rpm on yours
where this occurs
good information. Thank you.
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