Prop 1999 30 Mainship pilot sedan

Cboyle · Sep 15, 2016

Looking at changing prop, due to vibration issues , after 2200 rpms
All major systems were check, and passed .... Alignment , shaft, cutless bearing, and old prop, 22X26X4 LH,
Running Cummins 6bta, WOT 2600,
I understand there were vibration issues on the older boats, and Mainship added a 5 blade prop to help the issue.....

Any suggestions
Thanks charlie

Ricor · Jul 31, 2017

Same issue

I also have a 1999 Pilot 30, same vibration at higher RPM's but with a Yanmar 240hp.

Would love to see a reply to this post.

Keysdisease · Jul 31, 2017

I have followed this issue for a number of years. It seems as if Mainship in an effort to get maximum Kortz nozzle effect from the tunnel reduced the tip clearance. This resulted in "tunnel burn" in some boats and vibration in others. The 5 blade prop allowed the diameter to be reduced and the extra blade offset the blade area loss.

Hopefully a few P30 peeps will chime in with 1st hand experience

:socool:

Ricor · Jul 31, 2017

Mine being a 1999 did not have the tunnel. I think my issue has more to do with this;

"In its first year of production the Pilot™ 30 encountered noise and vibration problems particularly on boats equipped with larger Yanmar engines. The cause seemed to be insufficient propeller tip clearance and was addressed and repaired under warranty by Mainship."

Hopefully we will get some input! Thanks for your response.

Keysdisease · Jul 31, 2017

The "rule of thumb" for tip clearance is 10-15% of prop diameter. Same logic applies, smaller diameter + 1 more blade.

I believe there were some that reduced diameter and increased pitch, but that never seemed to work. Again, no 1st hand experience, just an interest in vibration.

:socool:

Baker · Jul 31, 2017

The tunnel did not come until 2003(Hence the many "upgrades" to call it a "Pilot II")...along with the OEM 5 blade prop.

Ricor · Jul 31, 2017

I wonder how it was "addressed and repaired under warranty by Mainship"

Prop 1999 30 Mainship pilot sedan

Cboyle

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Ricor

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Keysdisease

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Ricor

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Keysdisease

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Baker

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Ricor

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