Frequently Asked Questions: General Information

Parts and Services for the Universal Atomic 4 Engine
Parts: Phone: 717.625.3891 | 410.810.8921 | 717.625.1587 (fax)
Technical Service: Phone: 410.810.8920 | 410.810.8922 (fax)

FAQ: General Information

1. We removed our Atomic-4 2 years ago and had it rebuilt and tried to install it last week and once we got the motor in we found that we were 2in. out of alignment withe the prop shaft? the motor is setting to high. we had the rubber mounts installed even after removing them we are still too high. help

2. What would be the appropriate fuse and wire sizes for the main circuits within the engine DC power supply?

3. Have stuck valve on #4 cannot get head off. Managed to pry up about 3/8". Cannot get any looser. Just took off nuts. Studs are still on. Should I remove studs? if so, how do you remove them?

4. Looks like I need to remove the carburetor & exhaust manifold to adjust valves. Is that correct?

5. We recently purchased a 28 Newport with an Atomic 4. We were told the engine hasn't run in two years. What steps do you recommend to prevent any damage to the engine as we prepare to bring it back to life?

6. I'm planning a long trip, and although my engine is running quite well, I'm wondering what kinds of things I could check to make a breakdown less likely during the trip.

7. How can I tell the direction of rotation of my prop?

8. I have an Atomic 4 in my sailboat. I just measured the compression and got 0 for cylinder #1, 80 for cylinder #2, 120 for cylinder #3 and 120 for cylinder #4. I know the zero reading means a stuck valve, but does the 80 reading in the adjacent cylinder mean anything? Any recommendations on a plan of action?

9. What is the difference between an Atomic 4 and a Stevedore Atomic 4?

10. What is the proper torquing technique for head studs?

11. Where is the serial number on the engine?

12. Early or late model? How can I tell? What difference does it make?

13. A general approach to troubleshooting

14. Troubleshooting intermittent shutdowns

15. What would cause my engine to run with almost no power in forward, while it runs OK in neutral? It also seems to have more power in reverse than in forward.

16. What would cause my engine to falter, sometimes even backfiring slightly,as I advance the throttle too rapidly from idle?

17. Age

18. Things to look for when buying a boat with an A4

19. Starting with a hand crank

20. What would make my engine start hard, but then run perfectly OK once it starts?

21. Precautions when starting up an engine that has been sitting idle

22. How can I deal with head or manifold studs which fail to hold the specified torque values (35 foot-pounds for the head, and 25 foot-pounds for manifolds)?

23. Is it possible to use 3/8" coarse-threaded bolts in place of studs for installing heads and manifolds?

24. Knocking sounds in the lower part of the engine

25. Clicking sounds in the top of the engine

26. My Catalina 30 won't start.

27. I was coming back from a long trip with the engine on, when all of a sudden, the motor ran quieter. I quickly turned off the motor and raised the sails. I had to start the motor again when returning in the harbor, but it still was running poorly. Recently I checked it and found that it is only firing on 2 cylinders, but the plugs, plug wires and distrubutor all seem to be in good shape. Where do you think the problem lies?

28. Gas is ok, carb ok. Compression good on all 4 cylinders and I get spark ok, yet it will not start. Turns over ok with new battery. Do you have any suggestions?

29. What should the compression be?

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: 1. We removed our Atomic-4 2 years ago and had it rebuilt and tried to install it last week and once we got the motor in we found that we were 2in. out of alignment withe the prop shaft? the motor is setting to high. we had the rubber mounts installed even after removing them we are still too high. help; 2. What would be the appropriate fuse and wire sizes for the main circuits within the engine DC power supply?; 3. Have stuck valve on #4 cannot get head off. Managed to pry up about 3/8". Cannot get any looser. Just took off nuts. Studs are still on. Should I remove studs? if so, how do you remove them?; 4. Looks like I need to remove the carburetor & exhaust manifold to adjust valves. Is that correct?; 5. We recently purchased a 28 Newport with an Atomic 4. We were told the engine hasn't run in two years. What steps do you recommend to prevent any damage to the engine as we prepare to bring it back to life?; 6. I'm planning a long trip, and although my engine is running quite well, I'm wondering what kinds of things I could check to make a breakdown less likely during the trip.; 7. How can I tell the direction of rotation of my prop?; 8. I have an Atomic 4 in my sailboat. I just measured the compression and got 0 for cylinder #1, 80 for cylinder #2, 120 for cylinder #3 and 120 for cylinder #4. I know the zero reading means a stuck valve, but does the 80 reading in the adjacent cylinder mean anything? Any recommendations on a plan of action?; 9. What is the difference between an Atomic 4 and a Stevedore Atomic 4?; 10. What is the proper torquing technique for head studs?; 11. Where is the serial number on the engine?; 12. Early or late model? How can I tell? What difference does it make?; 13. A general approach to troubleshooting; 14. Troubleshooting intermittent shutdowns; 15. What would cause my engine to run with almost no power in forward, while it runs OK in neutral? It also seems to have more power in reverse than in forward.; 16. What would cause my engine to falter, sometimes even backfiring slightly,as I advance the throttle too rapidly from idle?; 17. Age; 18. Things to look for when buying a boat with an A4; 19. Starting with a hand crank; 20. What would make my engine start hard, but then run perfectly OK once it starts?; 21. Precautions when starting up an engine that has been sitting idle; 22. How can I deal with head or manifold studs which fail to hold the specified torque values (35 foot-pounds for the head, and 25 foot-pounds for manifolds)?; 23. Is it possible to use 3/8" coarse-threaded bolts in place of studs for installing heads and manifolds?; 24. Knocking sounds in the lower part of the engine; 25. Clicking sounds in the top of the engine; 26. My Catalina 30 won't start.; 27. I was coming back from a long trip with the engine on, when all of a sudden, the motor ran quieter. I quickly turned off the motor and raised the sails. I had to start the motor again when returning in the harbor, but it still was running poorly. Recently I checked it and found that it is only firing on 2 cylinders, but the plugs, plug wires and distrubutor all seem to be in good shape. Where do you think the problem lies?; 28. Gas is ok, carb ok. Compression good on all 4 cylinders and I get spark ok, yet it will not start. Turns over ok with new battery. Do you have any suggestions?; 29. What should the compression be?

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