Watermota Sea Panther - CAV DPA Injection Pump

[ncritchley]

Hi everyone, still needing help I'm afraid. I've got a query regarding the correct positions of the throttle and stop/start levers on a CAV DPA injection pump (model number 3247F160). I'm attempting to start the engine for the first time after the rebuild, and I want to have the throttle fully open, and the stop/start lever of course in the "run" position. If I look at the pump from the side with the drive shaft on the left, should the throttle and stop/start arms be fully rotated clockwise or anticlockwise? I can't see any indication on the pump itself. I hope I've explained what I mean! Thank you all.

 

[rogerthebodger]

I have a similar pump on my Perkins 4236

This shows the stop/run lever in the run position and the speed control in the idle position but will have the fueling fully open as controlled by the governor

The lft hole on the run/stop id the control cable and the right hole is for the return spring

 

[oldharry]

The throttle lever should normally be held in the tick over position by the spring, so that opening the throttel pulls it against the spring, anti clockwise seen from above. The governor will hold the internals at full speed until the engine fires and then shuts down to prevent it from racing. Its unwise with a newly rebuilt engne to rev it out to maximum on first start, It needs time for the oil to circulate and build pressure. The normal start posiition is aorund 25-30% throttle.

 

[ncritchley]

I have a similar pump on my Perkins 4236

This shows the stop/run lever in the run position and the speed control in the idle position but will have the fueling fully open as controlled by the governor

The lft hole on the run/stop id the control cable and the right hole is for the return spring

Apologies, I should have said that mine's the other type. I'll post some pictures shortly.

 

[ncritchley]

The throttle lever should normally be held in the tick over position by the spring, so that opening the throttel pulls it against the spring, anti clockwise seen from above. The governor will hold the internals at full speed until the engine fires and then shuts down to prevent it from racing. Its unwise with a newly rebuilt engne to rev it out to maximum on first start, It needs time for the oil to circulate and build pressure. The normal start posiition is aorund 25-30% throttle.

Thank you!

 

[rotrax]

Its unwise with a newly rebuilt engne to rev it out to maximum on first start, It needs time for the oil to circulate and build pressure. The normal start posiition is aorund 25-30% throttle.

Surely at first start you would crank the engine with the injector pipes loose so as to circulate the oil and build up pressure?

I always do. Simple enough and the amount of fuel squidged out is tiny. A bit of rag or paper towel in the right place sorts that.

 

[rogerthebodger]

Surely at first start you would crank the engine with the injector pipes loose so as to circulate the oil and build up pressure?

That to me is part of the bleeding process to remove any air in the injector feed pipes.

 

[rotrax]

That to me is part of the bleeding process to remove any air in the injector feed pipes.

Yawn......................................

Of course it is.

But, with a brand new or rebuilt engine that needs oil circulating around its vitals before startup, please suggest another way of achieving that outcome without decompressors, which no modern engines have.

 

[penberth3]

Yawn......................................

Of course it is.

But, with a brand new or rebuilt engine that needs oil circulating around its vitals before startup, please suggest another way of achieving that outcome without decompressors, which no modern engines have.

Crank the engine with the stop lever at "stop". We've all done it !

 

[rotrax]

Crank the engine with the stop lever at "stop". We've all done it !

Cant do that with my engine - advice is not to hold the 'stop' button in for more than enough to stop the engine to avoid overheating the electric solenoid coil. Which is why I just crack the injector pipes a tad. Simple with the Genset-that has a stop cable, but not the main engine.

 

[oldharry]

OP said he was planning to start the engine at full throttle... of course there are many ways of priming the engine lube oil galleries and bearings before starting, but OP seemed unaware of the need. Hopefully everything specially the shells was well lubed on installation, but a new engine racing on first start without fully priming the oil system?

 

[Roberto]

Apologies, I should have said that mine's the other type. I'll post some pictures shortly.

If it's the one with the hydraulic regulator, then fuel supply increases by turning the lever arm clockwise, the stop lever moved in the same direction stops the fuel flow. Be extra careful with the fuel supply, a few millimeters (degrees) of movement yield very different RPMs, I once disconnected the engine control cable to move the lever by hand, the engine rpm skyrocketed, be ready to put it back into a more normal position very quickly.
Also, the pump has a priming bolt on its body, plus the regulator can also be primed, when I need to prime mine (mounted on a 4108) that's all is needed, no need to touch the injectors.

 

[ncritchley]

OP said he was planning to start the engine at full throttle... of course there are many ways of priming the engine lube oil galleries and bearings before starting, but OP seemed unaware of the need. Hopefully everything specially the shells was well lubed on installation, but a new engine racing on first start without fully priming the oil system?

Thanks for this advice. I have actually turned the engine over a good few revolutions both manually and then on the battery to get the oil circulating to the essential areas. I hope this is sufficient. Everything was also well lubricated on reassembly.

 

[ncritchley]

Apologies, I should have said that mine's the other type. I'll post some pictures shortly.

Hi everyone, still needing help I'm afraid. I've got a query regarding the correct positions of the throttle and stop/start levers on a CAV DPA injection pump (model number 3247F160). I'm attempting to start the engine for the first time after the rebuild, and I want to have the throttle fully open, and the stop/start lever of course in the "run" position. If I look at the pump from the side with the drive shaft on the left, should the throttle and stop/start arms be fully rotated clockwise or anticlockwise? I can't see any indication on the pump itself. I hope I've explained what I mean! Thank you all.

Here are a couple of pictures of a (very dirty) pump of the same model as mine. You can clearly see the min/max positions for both the throttle and stop/start levers. I just wasn't sure which position was which. Thanks for all the pointers already supplied.

 

[ncritchley]

If it's the one with the hydraulic regulator, then fuel supply increases by turning the lever arm clockwise, the stop lever moved in the same direction stops the fuel flow. Be extra careful with the fuel supply, a few millimeters (degrees) of movement yield very different RPMs, I once disconnected the engine control cable to move the lever by hand, the engine rpm skyrocketed, be ready to put it back into a more normal position very quickly.
Also, the pump has a priming bolt on its body, plus the regulator can also be primed, when I need to prime mine (mounted on a 4108) that's all is needed, no need to touch the injectors.

Thanks Roberto, that's very helpful.

 

[oldharry]

Thanks for this advice. I have actually turned the engine over a good few revolutions both manually and then on the battery to get the oil circulating to the essential areas. I hope this is sufficient. Everything was also well lubricated on reassembly.

I would still not want to run a newly rebuilt engine at much more than fast tickover for the frist few minutes, not just to ensure theres plenty of oil, but to minimise damage in the event of faulty new components or incorrect assembly. I know of someone who wrote off his engine and boat because the flywheel broke free after a faulty bolt snapped.

 

[rogerthebodger]

After any rebuilt of both petrol and diesel engines I turn the engine over with the starter motor without sparkplugs or injectors to ger the oil circuiting using a oil pressure gauge to ensure there is oil circuiting and there is pressure without having compression pressure on the bearings.

I used to rebuild and tune BMC A series in my younger days.

We all have our different ways of doing the similar things

 

[ncritchley]

I would still not want to run a newly rebuilt engine at much more than fast tickover for the frist few minutes, not just to ensure theres plenty of oil, but to minimise damage in the event of faulty new components or incorrect assembly. I know of someone who wrote off his engine and boat because the flywheel broke free after a faulty bolt snapped.

Good advice, I appreciate this. I don't know why I was thinking of starting it on the fully open throttle setting. I wasn't thinking at all! In fact I used to fire up this engine on a halfway setting at most.

 

[ncritchley]

Thanks Roberto, that's very helpful.

And in fact if I put the throttle lever at a midpoint between the two stops, that should be about right I guess. Tomorrow morning I'll be trying it out. Fingers crossed.