Perkins engine help

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scottmain

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I have Perkins range 4 200 engines in a 1990 DeFever. I have been unable to find the wide open throttle limit for this engine in spite of hours of searching. Info on the web runs from 2400 to 3000 with all sorts of numbers in between. Does anyone have the wide open throttle number for this engine so I can target the props I am putting on the boat. Original props turned 2700 wide open. The four blade replacements are turning 2900 rpm WOT. If there is a place to fine this info I would appreciate the help
Scott
 
Scott

It depends on your HP rating.

135 HP -- 2800 RPM Natural
165 HP -- 2400 RPM Turbo
200 HP -- 2400 RPM Turbo and AC
240 HP -- 2600 RPM Turbo and AC
275 HP -- 2800 RPM Turbo and AC
 
Agree with Sunchase:

200hp--2400 wot

To verify the number is stamped on the injector or the flat surface it is mounted to. I am learning towards the injector though. It will be a number 10% higher than your wot. So for the 200 HP motor it would be 2640 which is 10% higher than the wot of 2400. If they did not set it over by 10% you would not be able to reach 2400 under load. The number stamped on the injector is referred to as high idle.
 
Check your reported rpms with a phototach. They sound too high. I would be a little surprised that a 2,400 rpm rated engine would run up to 2,900. Usually only 300 more. Also see what the engine will rev to with wot throttle in neutral.


David
 
It's stamped on the data plate for the injection pump. Located on the pump.
 
Just ran boat with old props. 3000 rpm wide open throttle. No load in neutral revs to 3500. Going to check readings for accuracy. Was told by shop the number stamped on the fuel pump is no load limit rpm setting will be less under load.
 
Check your tach. That is awfully high rpms for that engine.


David
 
Last edited:
Don’t do anything without a photo tach +/- 1 RPM
 
just happened across this picture of my injector pump. Note the last digits are 2640 which is 10% over the rated 2400 RPM of my engine.
 

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Thanks for the great reply’s. Mine is also stamped 2640 on the pumps. Getting 3000 rpm wot. 3500 no load. iPhone photo tach app showing 300 rpm less than ships yachts. Duvie, what is your WOT rpm? Looks like my tacos indicating high some but corrected rpm st
 
My Range 4 135 is a bit shy of 2500 at WOT. I doubt very much you're actually getting 3000 RPM. Quite a few of those engines get their tach data from the alternator. Might be worth a check on that. Do you have the correct alternator on there?
 

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