Cavitation.

[twinfisher]

I,ve got a cat with a single motor, now when i,m in a bit of a steep chop i can,t trim the motor up as far as i,d like to bring the bow up. I,ve got a long shaft motor . It,s not a big deal as the boat goes well but if i can improve it i will. Good luck all. Norm. l

[Guest Jocool]

So is there a question in there somewhere????

[Geoff]

Norm Let me guess , Webster 4.6mt with a 60hp & 13" prop. If correct , a permatrim will help.

Would be interested to know what speed your running at in the conditions described.

If it is the Webster , the boat rides best around 30km , 16 - 17 knots

Regards

Geoff

[twinfisher]

Norm  Let me guess , Webster 4.6mt with a 60hp & 13" prop.  If correct , a permatrim will help.

Would be interested to know what speed your running at in the conditions described.

If it is the Webster , the boat rides best around 30km , 16 - 17 knots

Regards

Geoff

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Geoff i,ve got a 4.3 with a 60 and a 10inch prop i can get along in a good chop at about 25 km. I,m happy with that but i just think that if i can trim up a bit it would improve it,s peformance. Maybe a bigger prop or as you suggest a permatrim. Thanks for your reply Norm.

[twinfisher]

So is there a question in there somewhere????  

57328[/snapback]

Sorry mate i wasn,t very specific was i

[Geoff]

Norm A friend has a 4.6 Twinfisher with a 60hp 4s Yammie , origionally supplied with a 13" prop.

Had all sorts of problems with cavitation but most was due to incorrect trim settings.

Tried an 11" Yamaha prop & then an after market prop. Not much change.

Fitted a Permitrim , refitted the 13" prop , this, combined with more familarity of the trim settings has all but elimated the cavitation problem.

Initally , suggest the 13" , see how it goes & fit the PT only if necessary.

For interest I have a 4.6 Twinfisher with a 70. It origionally came with a 13" & it was difficult not to cavitate. Changed to a 15"& the problem has gone.

Have no intention to fit a Permatrim or any other "wing" accessory at this time

Regards

Geoff

[twinfisher]

Norm  A friend has a 4.6 Twinfisher with a 60hp 4s Yammie , origionally supplied with a 13" prop.

Had all sorts of problems with cavitation but most was due to incorrect trim settings.

Tried an 11" Yamaha prop & then an after market prop.  Not much change.

Fitted a Permitrim , refitted the 13" prop , this, combined with more familarity of the trim settings has all but elimated the cavitation problem

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Thanks for that Geoff, good to hear from otherowners that have had the same problem.Regards Norm.