SailNet Community

SailNet Community (
-   Atomic 4 (
-   -   Atomic Is No Bomb (

sailnaway 04-07-2006 07:42 PM

Atomic Is No Bomb
I guess I am the only guy who loves this motor well me and Dom Moyer oh and Indigo Inc. This little gas motor is easy to maintain. It will take allot of abuse and keep you running. I have pushed my 22.000 LB boat for over 7000 KM in three years. I use it to power my inverter and watch movies because its quiet enough to do this. I do have to keep up with the points and all that because I am to cheep to buy the electronic ignition which is sold by Moyer and Indigo. My motor is fresh water cooled always was so it has a little longer life than some salt motors. For the gas worry I run the blower and sniff after a few seconds of running the blower if no raw gas smell then fire the puppy up. I also have the electric fuel pump and all the manuals which are as simple as the engine maybe 65 pages total. This motor was built from 1946-1979 with some being sold a little later. some where around 48.000 were built and many are still around. a rebuild will cost nearly $4000 from Moyer much less if you can do it yourself. All the parts are aftermarket and can be had easily. The company is now Universal and builds the small diesel which you can put in place of this ATOMIC if you want. I like this engine and do not plan to re power unless I loose a rod through the block or something. They all came with the Tranny attached which is also simple straight forward and a reduction in reverse. Never pass up a good boat because it has an Atomic you will be pleased at what you will learn from the ATOMIC 4 groups and die hard ATOMIC enthusiasts like me. Thanks to Don Moyer and Indigo for the fine products and service they offer. The ATOMIC is no BOMB.:)

Henry Stafford 04-18-2006 02:00 AM

Re: atomic4 no bomb
I have an atomic 4 in my 1974 Ericson 27'. The impeller went to pieces and overheated the engine (to the point of discoloration). I did not see the temp guage since it was mounted on the inside of the cabin on the instrument panel. So I added a panel in the cockpit, moved the gague, and added a tackometer. Before I could replace the impeller a leak developed in a hose an put the motor under water. I had a tech who had worked on atomic 4s get the engine working again. The engine starts as soon as you hit the switch and runs fine. It appears it can not be killed no matter what happens to it. My problem is that the steel gas tank has crap in the bottom (probably rust) and there is a Fram "special marine" gas filter (FBM1110-PLM) that I can't find a replacement for. I would like to replace the gas tank with a plastic one and replace the filter that sits between the tank and motor. Any suggestions?

Henry Stafford

Jim H 04-18-2006 08:08 PM


Originally Posted by Henry Stafford
My problem is that the steel gas tank has crap in the bottom (probably rust) and there is a Fram "special marine" gas filter (FBM1110-PLM) that I can't find a replacement for.

As for your filter, could this be it:

Note that the replacement filter is linked at the bottom of the page, and costs about $7.50.

Thanks for the stories about your Atomic 4 "surviving everything." I've only had mine a short while, but it runs really well and I hope that it's as bulletproof as yours.

Jim H

captainbrad 05-25-2006 04:55 PM

Yes, this is a great little engine. It's simple, quiet, easy to maintain, and everything is easy to get to (well, depending on your boat too I guess).

The impeller incident Henry writes about is not uncommon. Same thing happened on my dad's old Columbia 31. One fin of the impeller wedged itself in the cooling system and essentially stopped all water flow. It didn't sieze, but it did require a major overhaul. I remember as a kid having one winter with A4 parts spread all over the basement :-).

3 key things w/ A4 impellors:
1) Always carry at least one spare and know how to change it at sea. If you want to make it easy on yourself, get one of those aftermarket kits with the thumbscrews and the quick release cover.

2) Change it every spring religiously. Doesn't matter how much you used the boat last year, just change it. If you didn't use it much, keep the old one as a spare, but mark it with a tag as limited lifespan spare only.

3) Install a simple temp and oil pressure alarm. I found one at Boat US for under $20. Very easy to wire and install. Put the buzzer where you can hear it from the helm, and maybe wire a light to it as well. That way if the engine does begin to overheat, you'll know hopefully before any damage is done.

Othewise this is a great engine. I've got mine running so well that it'll idle at about 100 RPM IN GEAR!

This is always a good resource if you have questions or problems with your A4.


mschwarz 05-25-2006 09:05 PM

I'm another atomic fan! I have the Atomic 4 in a 1961 Pearson Triton (hull #229) that has been a work horse for many many years. Moyer rebuilt her in 2001 and the few upgrades that were added make her better than ever. We just put this '61 Pearson Triton up for sale due to our finally being able to afford something bigger, but we'll miss that dependable motor!

russell32 06-04-2006 04:25 PM

After some research, I decided to replace my Atomic four with another A-4 takeout. The mechanic doing the installation assures me the takeout is a good motor and it should bolt right in. People on the dock come by and offer advice and encouragement regarding the A-4. Wish me luck!!!

SeattleIanReilly 07-16-2010 05:45 PM

Hi - My 1978 raw water cooled Atomic 4 has spent most of it's life in the salt. It now has a cracked head. Starts easily, runs rough. New coil, waterpumps, some other bits. I am curious how easy it is to determine if it is a good rebuild candidate. I have heard stories of ppl rebuilding them only to be destroyed shortly after by corrosion. compression ranged 95/105/108/113. Is there a way to inspect the guts/waterpassages without removing the block?

nightowle 07-17-2010 02:28 AM

you can probably attach a new head. Why not repost your question under a new post to get more input rather than attached to this old thread? BTW - love my A4

Hackettsan 10-21-2011 12:23 PM

Where can one find a replacement impellor and how simple is the install?

imagine2frolic 10-21-2011 12:43 PM

The pump is an Oberdaffer, and readily available. You can get tune up parts at places like Pep boys. It is the same engine on a million fork lifts, and parts are A/C Delco......i2f

All times are GMT -4. The time now is 03:35 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
(c) LLC 2000-2012

For the best viewing experience please update your browser to Google Chrome