Visit our Popular Forums

Hoohaa · 01-01-2012, 14:45

Hi All
I have a 50 hp Perkins 100 series on my Yacht. It runs smoothly, starts easy. But will not go over 1000 rpm. The manual states it should rev as high as 2500.
The problem is not in the cable linkages as we have disconnected it and throttled it manually.
When you rotate the accelerator lever on the engine by hand it stops well short of the stops which are meant to limit the movement of the arm. It feels like there is something internal which stops it moving past a point.
ie. It rotates normally to a point and bumps on something internally which prevents it from rotating any further, which in turn restricts the rpm to about 1000.
I have only owned the boat for 1 month and did have a marine mechanic survey the motor before purchase and he tells me he was able to rev the engine past 2000 rpm.
Any ideas would be greatly appreciated.
Regards Jeff

**atoll** · 01-01-2012, 14:57

sounds like you got a screw loose!
best get a diesel maccky on it,unless yr confident to take the pump/guvner off yourself.

B.O.A.T=bring on another thousand..........

delmarrey · 01-01-2012, 15:33

Quote:

Originally Posted by Hoohaa

Hi All
I have a 50 hp Perkins 100 series on my Yacht. It runs smoothly, starts easy. But will not go over 1000 rpm. The manual states it should rev as high as 2500.
The problem is not in the cable linkages as we have disconnected it and throttled it manually.
When you rotate the accelerator lever on the engine by hand it stops well short of the stops which are meant to limit the movement of the arm. It feels like there is something internal which stops it moving past a point.
ie. It rotates normally to a point and bumps on something internally which prevents it from rotating any further, which in turn restricts the rpm to about 1000.
I have only owned the boat for 1 month and did have a marine mechanic survey the motor before purchase and he tells me he was able to rev the engine past 2000 rpm.
Any ideas would be greatly appreciated.
Regards Jeff

Sounds like the governor.

Hoohaa · 01-01-2012, 16:12

So if I chuck another thousand at it? Where do I wedge the $20 $50 or $100 bills? Sopose it will get fixed quicker if I use hundreds.
But seriously. What is the governor for and does anyone know why it would start behaving like this? I may of missed its monthly back hander?

**atoll** · 01-01-2012, 16:18

it is probably a spring that is broken,or one of the internal set screws that have vibrated loose.
use your initiative with cash.......welcome to the world of yachting

CharlieCobra · 01-01-2012, 17:07

My old Perkins 50 would rev to 3400. The one in the Mariner will limit at 2500.

delmarrey · 01-01-2012, 17:09

Quote:

Originally Posted by Hoohaa

So if I chuck another thousand at it? Where do I wedge the $20 $50 or $100 bills? Sopose it will get fixed quicker if I use hundreds.
But seriously. What is the governor for and does anyone know why it would start behaving like this? I may of missed its monthly back hander?

The governor is a throttle device in the injection pump that keeps the motor from over reving. Diesels can only run at slower speeds due to their compression ratio. If they go too high, they'll blow apart.
Yours may be hydraulic, don't know w/o a parts list. Older boats just need more attention.

**Tellie** · 01-01-2012, 17:31

Are you reving it in or out of gear?

delmarrey · 01-01-2012, 18:27

Here's a steam locomotive governor form 1857 that I had to rebuild. The spinning balls expand out which closes the valve that controls the steam flow, that injects steam into the cylinder lines.

ATC · 01-01-2012, 18:40

Quote:

Originally Posted by delmarrey

Here's a steam locomotive governor form 1857 that I had to rebuild. The spinning balls expand out which closes the valve that controls the steam flow, that injects steam into the cylinder lines.

and, Then you have 'Balls to the wall".

JiffyLube · 01-01-2012, 19:25

Quote:

Originally Posted by Hoohaa

Hi All
I have only owned the boat for 1 month and did have a marine mechanic survey the motor before purchase and he tells me he was able to rev the engine past 2000 rpm.
Any ideas would be greatly appreciated.
Regards Jeff

Ask the surveyor to come back to your boat, and show you how it got over 2,000 rpms.

Hoohaa · 01-01-2012, 20:45

Quote:

Originally Posted by Tellie

Are you reving it in or out of gear?

We are reving out of gear & in gear.
Jiffylube
I have spoken to the surveyor (Marine mechanic) who is on holidays ATM and yes, its amazing what he wants to do with the engine to pring it up to a profesional standard, I got the impresion that I could spend a fortune on it if I let him off the leash but he never had an answer for the current problem at this stage.
I am shore he is good intensioned and I think he would not have much trouble getting to the heart of the problem. But, I would prefer to fix it myself, as much for the learning as for saving a couple of dollars. Thats why I am talking to you guys.
I can usually work my way through most repairs once pointed in the wright direction.