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I’ve got an Oman 2.5AJ that won’t start. Nat gas, was

Customer Question
Hi I’ve got an...

Hi I’ve got an Oman 2.5AJ that won’t start.

Mechanic's Assistant: Do you have fuel in the tank? If so, is the shut-off valve open and the fuel clean?

Nat gas, was running Beautifully, low oil triggered shut down. Changed oil, but no luck. No spark, I think it’s tied to the low oil sensor kill switch, if such a thing. The unit is a 1972??? . It’s been running great through our latest Nor’easter, power is going to be out for three days anyway.

Mechanic's Assistant: Do you plan on doing the work yourself?

Yes

Mechanic's Assistant: Anything else we should know to help you best?

Is there a simple fix that I’m missing

Submitted: 1 month ago.Category: Small Engine
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Customer reply replied 1 month ago
Unit was running excellent until low oil shut off triggered. I believe it’s a shut off safety sensor or something like that? Any help would be greatly appreciated.
Thanks,
Jack
Customer reply replied 1 month ago
I held the on/off switch to the off side for 15-20 seconds during the last storm and it fired right up after the same situation occurred.
Answered in 1 hour by:
3/14/2018
Technician: Hank F., Technician replied 1 month ago
Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 15,637
Experience: Certified on Onan and Generac generators
Verified

Hello, my name is ***** ***** I am going to assist you with this.

AJ is only the basic series .

What is the full model and serial number of the genset?

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Customer reply replied 1 month ago
Hi Hank, thank you for your help. The unit is a 2.5AJ-3R/12K SN-0273565261 Thanks, Jack
Technician: Hank F., Technician replied 1 month ago

Ok.

First, your unit was manufactured in February of 1973.

This unit has a low oil pressure switch, not a low oil level switch.

The LOPS is bypassed during cranking, so if you do not have spark during cranking, it is not the LOPS.

This unit also came with 2 different types of ignition systems.

Does your unit have an automotive type coil, or not?

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Customer reply replied 1 month ago
I don’t know which ignition system, I would have to pull the magneto, correct. Would you know of any unpublished sequences to bypass the fault? If you have a couple of potential solutions, that would be great. The unit runs beautifully, but there is a signal or code deterring ignition. Thank you, Jack
Technician: Hank F., Technician replied 1 month ago

You don't have to pull anything.

Just follow the spark plug wire. It will either go to a coil mounted on the outside of the engine, or it will go down under the engine cover.

I can't tell you how to test anything until I know which system you have.

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Customer reply replied 1 month ago
It goes into the backside of the mag. Under the head and sheet metal to the coil. I took all the sheet metal off the other day when it happen, 5 days ago due our last storm.
Technician: Hank F., Technician replied 1 month ago

Then you have a magneto type ignition, and not a coil type ignition.

The first thing you need to do is to remove the plug wire from the spark plug, and ohm from the plug wire to a good ground. You should get a reading of about 10,000 ohms.

What do you get?

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Technician: Hank F., Technician replied 1 month ago

Have you tested this yet?

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Hank F.
Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 15,637
15,637 Satisfied Customers
Experience: Certified on Onan and Generac generators

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