Perkins 4.236 low RPM

Edwmama

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Hello fellow sailors


Thx to the internet I get tips advices and help on how to trouble shoot and fix problems

This time I have a new problem with my 1968 perkins 4.236 85 bhp engine in my cal 46 sailboat, Lahlia which hails at Marina del Rey CA


I seem to remember that I was able to rev my engine passed 1500 rpm before

Recently it'd only go to 1000, achieving only 5 knots. Most of the time the engine starts right away, (requiring rebleeding at times) No black or white smoke. It runs smoothly. No water in the oil. It's not burning oil, no funny vibrations. Sounds great according to visitor engineer. Engines feels smooth and doesn't get hot fast
It has 1100 hours ( almost new)

Yesterday I had replaced my secondary fuel filter fearing ( on someone's suggestion) that I had reversed the O ring placement on the engine-attached fuel filter.... That was okay

But I did discovered that the O ring on the primary Racor 500 had been TWISTED. After this rectifying this and After bleeding the engine, I ran the engine to 180 F temp and I was able to reach 1500 under no load ( while at dock)

My stainless steel fuel tanks have been cleaned 5 years ago. The auxiliary
Electric fuel filter is clear and the fuel looks sparking clean coming out of the Racor before it feeds into the engine

When I ran my auxiliary fuel pump it puts out fuel readily indicating there is no impediment
Or obstruction to the flow from the hoses and fuel tanks, which contain biocides and stabilizers

Does anyone know why my RPM is not reaching maximum? And how can I rule out
Problems with injector pump or perhaps lift pump

Thanks in advance

Edwmama
Cal 46 Lahlia
MdR CA
 

Edwmama

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Thank you kindly for your response
I did take it out after fuel filter replacement and it's the same: lacks power and RPM only tops 1000
I had a mechanic do differential testing and now I'm in the process of removing the fuel injection pump

I am at the last and final step: the 3 nuts that hold the pump to the engine are removed and the injector pump won't budge. I am at step 7 of the workshop manual
I've etched the lines on the flange and timing case etc

Is there anything special when I actually pull it out?
 

Edwmama

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23 Feb 2014
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Thank you kindly for your response
I did take it out for a test run after fuel filter replacement and it's the same: lacks power and RPM only tops 1000
I had a mechanic do differential testing and now I'm in the process of removing the fuel injection pump

I am at the last and final step: the 3 nuts that hold the pump to the engine are removed and the injector pump won't budge. I am at step 7 of the workshop manual
I've etched the lines on the flange and timing case etc

Is there anything special when I actually pull it out?
It's stuck and I'm afraid to twist it
A friend suggested a putty spatula and a gentle rubber mallet

One it's loosen anything special or precautions when I ACTUALLY DO PULL IT OUT?


Edwin
Lahlia
Marina del Rey CA
 

WFA

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Before getting too technical it is always worth checking the basics.
Engine flight speed OK ie out of gear and open the throttle by hand.
If the engine revs are OK then check the shaft free to turn by hand, gearbox oil etc.
Then have a look at the propeller (from the dock, take a swim or when the boat is ashore) for any fouling material.
 
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