Originally Posted by jamie mac
I am the third owner guy i bought it from told me original owner turned it bsck because he was old school and didnt think a diesel should turn 3800 .it is a 6lpastp 315 it has the microcommander engine controls under load it is 3000 rpm in neutral i wont know til monday when i am home.it does have a five wing prop but i dont know if that is what it came with. thanks for the info.ps wot 21 knots
Well here is a start. I would go to Boat Diesel.com. Join as a level 2 member . That is $50 a year. Then go to the Engine section and then to Yanmar. Then to the older engine numbers an you will see your engine listed. The High Idle is 3,800 RPM. 80% of that is 3,050 which is where your engine should run most of the time. So what that means is that in neutral your engine should be able to rev up to 3,800 WOT and in gear it should be able to do the same at WOT. Now it may take it a minute or two to get there but it should obtain something real close to that in semi calm water. So is it doesn't get to 3,800 in neutral someone has tampered with the set screw on the fuel injection pump. This is not good. If it gets to 3,800 in neutral and not to 3,800 underway then the prop is not correct. This is not good either. If it does both then you can run at any RPMs you want but that engine needs to see 3,800 for a little time every time you leave the dock so to keep the engine clean and the turbo clean.
The folks on Boat Diesel will help you out. Tony Athens is one of the top Yanmar Technicians in the country and he can answer your questions as they come up. He has a very good article called 'Propellers Move Boats - Engines Only Turn Them" right on the front page of the home page.
I have the same throttle control system as you do and that I know of there is no way to dial it back.
The question is how did it get past the survey on the sea trial ?