TAMD41P max revs

[R400]

Does anyone know what the revs should be at full bonk. Our MF 805 is doing 4200 at wot giving 24 knots on the gps. Don't get me wrong I'm delighted with the performance but my previous MF with 200bhp wasn't as quick . This one has a20x21 pitch prop 4 blade.
Does anyone know where to buy QL trim tabs.
Many thanks

 

[duncan99210]

Might do better posting this on the motor boat forum.

 

[VicS]

Does anyone know what the revs should be at full bonk. Our MF 805 is doing 4200 at wot giving 24 knots on the gps. Don't get me wrong I'm delighted with the performance but my previous MF with 200bhp wasn't as quick . This one has a20x21 pitch prop 4 blade.
Does anyone know where to buy QL trim tabs.
Many thanks

Maybe not exactly the answer to your question but according to the table in the Operators Manual (q.v.) the rpm at WOT should be in the range 3700 to 3900

 

[Plum]

Does anyone know what the revs should be at full bonk. Our MF 805 is doing 4200 at wot giving 24 knots on the gps. Don't get me wrong I'm delighted with the performance but my previous MF with 200bhp wasn't as quick . This one has a20x21 pitch prop 4 blade.
Does anyone know where to buy QL trim tabs.
Many thanks

Should be between 3700 and 3900. I have the same engine in a 3tonne displacement. What is your displacement.

Www.solocoastalsailing.co.uk

 

[Quandary]

Might do better posting this on the motor boat forum.

Why? PBO used to be a very broad church.
As a recent (and reluctant) convert I tried asking stuff on there, I don't think they are much in to technical stuff, I suspect that they usually get a man in.

 

[Momac]

You will potentially damage the engine if you exceed the rated engine speed.
Even then you should be cruising at less - say about 3300 rpm which is the max I do on volvo penta engines with the same rated maximum engine speed.
Sounds like the prop may have been changed as you suspect. I really don't know why people change props from when the boat builder has gone to the trouble of getting it right.

 

[Plum]

You will potentially damage the engine if you exceed the rated engine speed.
Even then you should be cruising at less - say about 3300 rpm which is the max I do on volvo penta engines with the same rated maximum engine speed.
Sounds like the prop may have been changed as you suspect. I really don't know why people change props from when the boat builder has gone to the trouble of getting it right.

You are right about having an underpropped engine alowing it to over rev, however, the owners manual for this engine states "Volvo Penta recommends a
cruising speed approximately 200 rpm lower than maximum rpm at wide
open throttle" so at 3900 max that would be 3700. I am not saying that is what you should cruise as, just that VP are saying it is acceptable.

Www.solocoastalsailing.co.uk

 

[duncan99210]

Why? PBO used to be a very broad church.
As a recent (and reluctant) convert I tried asking stuff on there, I don't think they are much in to technical stuff, I suspect that they usually get a man in.

Because there is something of a bias towards sailing boats in this forum. In addition, I've never seen any mention before of the trim tabs part of the OPs post on this forum. And the post was half way down the page with no responses, so it seemed reasonable to suggest a repost elsewhere whilst also bringing the post to the top of the page again.

 

[alancollins]

I have a TAMD41P engine and the handbook states max revs are 3800. You are a bit under-propped and, rather than change it, I would simply keep the revs down.