Re: [Amel Yacht Owners] Re: Yanmar 75HP - Cannot go over 2300 RPM


As I stated above in this thread, I also have low engine RPM. It was 2500 RPM maximum when I bought my boat. I have 75 HP YANMAR with transmission 2.8:1 ratio. I contacted US Autoprop representative. He forward my question to the factory. See below their reply.  I copied and pasted it below.

"As far as I am aware Amel have not advised us about using Yanmar engine so this prop was never set up for this engine. Our records show that they only used Perkins or Volvo so it is not surprising that the pitch is out. Probably never right from day one. Say that however, it should not be too far off the mark in terms of engine loading. My best guess is that if the turbo is not working this is the reason for the low maximum rpm and not because the prop is holding it down."

My boat is on the hard now. I plan to check torbo when boat is in the water. I will conduct some other tests. If I could not resolve the problem I will remove the prop and send it to US Autoprop representative for a pitch change.


On Jan 11, 2017 7:16 AM, "David Pawley pawleyd@... [amelyachtowners]" <> wrote:

Its possible there are 2 types of injectors for the same engine, one set for derated. The difference would be seen in the nozzle hole Dia. Have you still got the old injectors!. Visual examination should be adequate but better to use nozzle cleaners. I have no idea if Yanmar have derated injectors, but other large bore engine manufacturers certainly have.

On 11 January 2017 at 16:34, 'sailormon' kimberlite@... [amelyachtowners] <> wrote:


The autoprop rebuild is not difficult just tedious and takes the  good part of a day.

If you Contact AB the bruton distributor in the USA they will sell you the bearings needed and rent you the special tools needed for the rebuild at a nominal price.

Fair Winds


Kimberlite Amel Super Maramu #376


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