Rosa master model db

georgelemon

New User
I have this Hercules power unit that has a rosa masters db injection pump. I went to start it n no go. It has the electric shut off device (12 volts ) set for energized to run. Should you hear a click when you turn the key on? In other words should you hear the solenoid close pulling the governor linkage hook rotating the metering valve to open. I hear nothing. I have voltage to the retaining nut. I checked the ohms between the two contacts and it read zero. I would think there would be some resistance . Eight years ago I sent the injection pump in to rosa masters and they completely went through it. When I got it back I put in on the engine and it started right up. I ran it for twenty minutes. Then I put the unit in heated storage until now. Can I take the governor control cover off with out removing the whole pump. Any experts have any ideas? If anyone would like to call me I would love to talk about this problem. Or email me at [email protected] . My number is 608-697-8508 .after 8:30 am n before 5pm thanks guys.
 
Yes, you should hear a distinctive little "click" when the solenoid gets energized.

The shutdown solenoid doesn't actually move the governor linkage and metering valve, it just retracts out of the way so a small spring can move the linkage to the "fuel" position.

The terminals of the solenoid are typically both insulated from the pump body, so if you are applying 12 Volts to one, the other needs to be grounded, either with the little factory-made ground strap to one of the cover mounting screws or a separate ground wire.

Is one or the other in place?

As to your Ohm reading, I'm NOT sure what would be normal, but if the one terminal is grounded and power is actually being applied to the other, it's NOT shorted, or you'd be blowing a fuse or "letting the smoke out" somewhere.

If the ground is in place with no results, it's possible the solenoid plunger has stuck in it's bore.

You can easily remove the three screws and cover and have a look, nothing's gonna "jump out at you".

Putting the cover back on takes a little more detail, the "tab" protruding from the cover unit has to properly match up with the tab on the governor link and pull it to the "no fuel" position before the cover is lowered into place, or the linkage will be jammed/mangled leading to full fuel/no engine shutdown. NOT good!

For some models, Stanadyne sells a little hook tool to hold the solenoid retracted during assembly, making this easier, or the solenoid can be energized into the "run" position with jumper wires during installation accomplishing the same thing.

But with care, it can be installed without resorting to either of those options, just be sure it sits down up against the pump housing easily by hand before snugging down the three screws.

Good luck!
 
Hi bob
I read about a grounding washer of sorts. Is it possible there is one on mine and that's why it started before. Or did I just forget I grounded the other terminal
 
sounds like the metering valve in the pump may be stuck. May have to lift the top cover and check it out.
 
If you are checking resistance between the two terminals - it has to be 6-7 ohms. When hooked to 12 volts, it will draw around 2 amps.

Yes, you can take the cover off with the solenoid attached to it - with the pump in place.
 
Make sure you are checking resistance AT the two studs and not between any connectors or chassis ground. There are various versions of
solenoids used in DBs and DB2s, but all have two studs with rubber insulators.
a263956.jpg
 
(quoted from post at 02:28:21 04/05/18) Pictures are labeled wrong..
Mid & new are backwards.
Hello,
I didn't have to do anything except hook up the ground wire. When I did that and hit the starter it sat there and purred like a little kitten. Just beautiful . I would like to thank each and everyone of you for taking the time to help out. Thank you.
Now I have one other question. The unit starts up and runs counter clock wise. Is there a way to make it run clock wise. I see there is place to mount the started on the other side of the engine. Can it be as simple as that. (In my dreams right). If there is a way could you please advise. The reason is because my 1932 frick saw mill is a left handed mill. I have an 87 horse silver diamond IH engine running it now but it just doesn't have enough power to do the job. The IH PTO runs clock wise so all I need is a drive shaft. So if I can get the Hercules to run clock wise that would simply things. Again thank you for all your help, please advise.
 
No, not labeled wrong. Newest solenoid in that photo is the open-coil dated 1982. New ones after that again have closed-coils. Order is correct as I labeled.
 
I am no Hercules expert although I have a few (gas and diesel). Like any other 4-stroke-cycle engine - the camshaft is the main issue. You
need a way to make it run in reverse. How you do that with your Hercules? I suspect if Hercules made another version with opposite
rotation - it came with a special reverse camshaft. Chevy did that with many gas V8 truck engines.

That is just the basic engine change needed. You'd also have to convert the fuel injection pump to reverse rotation.
 
CCW at the shaft should be correct for both engines. You may have a reduction gearbox on the IH engine that
changes direction. If so, it may mount on the Herc engine.
Is that engine a 339?
 
Hi George, your shop gave me a fond memory of
a very dear friend. He could do anything involving
machinery. His shop looked 'busy' as does yours.
sorry I don't know much about Hercules engine but
a neighbor needed a ring gear for his little Hercules
engine and he found one to fit off an old Datsun
pickup. Good luck to you! Ed Will Oliver BC
 
Hi Ed, thanks for the comment . It seems to be a nice size for me. I seem to work on four projects at the same time. Seems to be cheaper for buying parts. Thanks again, george
 

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