Adjusting minimec diesel pump

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Frank mellin

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Advice please.
My boat is fitted with 2 4ltr ford dover engines with minimec diesel pumps.
There looks to be an adjusting screw on the top of each pump adjacent to the oil filler plug.not sure which way to turn to reduce fuel supply as engines have been running very rich.
Some guidance would be appreciated.:o
 
I don't know those engines but I would be cautious about adjusting anything on the pumps unless they have already been adjusted and you are trying to get them back to where they were. Have you looked at other causes of overfuelling like air filters, fouling, blocked exhausts etc?

Richard
 
Leave alone as you are barking up the wrong tree. It is a diesel and not a petrol engine. Diesels are speed controller by varying the fuel supply and so if you feel the engine is running rich you need to look elsewhere such as exhaust elbow air intake system etc.
Those screws should probably only be tweaked by an injection specialist with the pump on a calibration machine.
 
I wouldn't touch the fuel metering, firstly because if you don't know exactly what you are doing then you'll make it worse. Secondly it's very unlikely to be the cause of your problem.
What symptoms are you trying to fix? Black sooty exhaust smoke and poor revs/performance?
If the engine was OK but isn't now, I'd check for prop and hull fouling.
It would be worth checking the air filter isn't clogged up and reducing air intake. If they are OK, next have a look for soot build-up inside the exhaust probably near the elbow.
 
Frank mellin said:
Advice please.
My boat is fitted with 2 4ltr ford dover engines with minimec diesel pumps.
There looks to be an adjusting screw on the top of each pump adjacent to the oil filler plug.not sure which way to turn to reduce fuel supply as engines have been running very rich.
Some guidance would be appreciated.:o
Click to expand...

You can reduce the fuel flow by undoing the locknut and screwing IN the screw, but as said elsewhere, it is not normal to have to do this. Pumps are set on a test bench to a set flow rate. If you do decide to do it I would suggest about one eighth of a turn. When I used to work at Ford Dunton test lab we used to do this while the engine was running at full load/ speed. It tends to concentrate your thoughts on the bits flying round and up and down near your Crown Jewels !
 
I had a 6 cyl Ford turbo, the pump was serviced and on return the engine would not achieve full revs. The engineer had adjusted it for a non turbo application. After ringing Mermaid, we removed the side plate, ran the engine up at sea under load and opened the screw until it smoked, then back a bit.
However, I'm guessing you have black smoke and there will be other reasons for this, fouled prop, lack of air or really knackered pump and injectors.
 
Thanks for all the informationand noted.
The pumps are from the 70s so guess they could be on the way out although both engines start very well.
Im told the boat was capable of 17 knots but the most i can get is about 10 and thats at about 1800rpm.
The strange thing is that if i open engines up to about 2800rpm the boat goes no faster.
Had hull antifouled at beginning of year but cheap paint used and i notice hull is collecting debris already.
Could this cause the loss of 7knots.?
 
I would be interested to know what hull you have. 17 kts is quite ambitious for twin engines that are, if naturally aspirated, about 80 hp each. The engines will be struggling to shift their own weight let alone get the boat over the hump and planing. When you open up to 2800 does the boat just stand on its tail and go no faster? Is there a lot of black smoke?
 
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