Adjusting Governor Perkins T6.354

[db2]

Hi all,
I have a 1974 Californian 42LRC with 2 Perkins T6.354 engines fitted with hydraulic governors. While investigating a potential over prop situation, i discovered that the problem may be too low of a WOT set point. I have found that the control cables are set up with too little throw and I can handle that. However, the hydraulic governors have me scratching my head and I could use some help. There does not seem to be much information in the CAV user manual and the Perkins workshop manual is next to useless about the governors. OK, so here is my problem: the control lever on the governor moves up and down to regulate fuel and I get that, However, the lever also rocks back and forth to activate another function which I don't understand. It looks like the rocking regulates fuel enrichment or something. Any way, my control cable angle of attack makes the lever rock which makes the idle speed increase. How is the cable and lever supposed to be set up. Also, once I get the control cable to lever issue resolved, how do I set the WOT limit to 2400 rpm?

thanks in advance,

Dan

 

[jleonard]

You must first set the High Idle (or WOT with NO load) to 2950.
After that your WOT under load will be determined by the load on your prop (diameter, pitch, boat loading). If you don't get 2400 rpm, then you'll have to adjust the prop.
I don't have a good diagram showing the governor adjusting screw, but it's on the aft side of the pump (if memory serves) and it's "sealed" with a lead thingy and a wire. You'll have to break the seal and turn the screw to adjust the high idle to 2950.
The idle adjusting screw is spring loaded (external spring) and should be easy to find.
That was how my circa 1978 Perkins was set up.

 

[gaston]

First thing I would do is check for slip in the gearbox it dosn't take much to loose a few 100 rpm's

 

[Brooksie]

The WOT no load should be set to about 3150 but check your pumps for exact rpm. It is part of the model number on the tag. The actual adjustment is a small slotted screw, under a rubber plug, beside the low idle screw. Hard to find

The "rocking" you refer to does nothing and may be a function of the angle that your cables enter the levers This too may need to be corrected to prevent other problems.

 

[Baker]

I was once told this thing is rarely out of whack and you are opening a can of worms by messing with it. Not sure it is as easy as it sounds. Which is why they safety wire it and cover it. They don't want you jacking with it....just my scared little opinion...

 

[Ski in NC]

If rpms change when bumping against idle stop, sounds like the bushing in the cover is sloppy.

 

[db2]

Thanks everyone for the information. I will take a hard look at the pumps with good lighting. It looks like I will need to find the WOT adjustment under a cover and/or safety wired. I will also evaluate the shaft/bushing for wear. After all, these pumps have been in service for the lifespan of the original engine build and 1-2 overhauls. they seem to be functioning fine, just out of adjustment.

thanks all,

Dan