Atomic four replacement

Aug 29, 2014
1
C&C 30 Mark I Falmouth
I currently have an Atomic Four in my C&C 30 Mark I - I am going to replace it withj a diesel - either a Yanmar or Unioversal. Have any C&C owners done this and what was their experience?

Thanks
 
Mar 30, 2013
700
Allied Seawind MK II 32' Oologah Lake, Oklahoma
Why replace the A4? A rebuilt or "new" A4 from Moyer Marine would be cheaper and simpler than swapping to a diesel.
 

BJV

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Jun 8, 2004
61
Island Trader 41 foot Ketch, CC Arnold
dito on beta, they have mounts that will fit original beds.
 
Dec 6, 2010
50
Catalina 30 City Island
Ive had both the atom bomb and a diesel. Both have their good points but switching fuel types is more work than just replacing. Atomic 4 are great powerful engines in addition to the engine and fuel supply system youll also have to figure out the correct prop, a4's were typically direct drive while diesels have transmission. Very differnt props for these. The moyers rebuld / reconditioned with exchanging your block is likely the most cost effective and easiest. A problem with boats originally designed for the a4 when replaced with diesels because the rpm on the prop was lower with higher torque. Diesels want larger props to match the performance of the a4 dont go less than 20hp. Depending of the displacemnt possibly less than 25 hp.
 
Dec 6, 2010
50
Catalina 30 City Island
An A4 with the indigo ignition, and freshwater cooled will last a very long time, is powerful much quieter, especially if a waterlift muffler than any diesel will be.
 
Dec 7, 2012
515
Kittiwake 23, Irwin 43 .. Indianapolis / indianatown, fl
hello all

I have a 71 Morgan 35' sailboat... about 2 years ago the universal atomic4 went bad and the old owner decided to sell his boat.... I picked it up for a good price and I got a deal on a new Kubota diesel... I am very happy I changed to the diesel instead of putting another gas engine into it...

it is easiest to change same type of motor with another like motor, everything is the same for hook up...when changing to a new type of fuel source, you have to scrub the old tank completely or replace it, and install all new hoses for the fuel delivery system... it is more work than just installing another gas motor into the last ones place...

another thing to remember too, placement of all the other hoses too... fresh water for the cooling system, water exhaust system, motor mounts.... some or all of these things might not line up properly with the new motor unless it is the same type motor... I had to run all new hoses to everything, plus my old gauges had to have all new fittings, as they were different than what I had for the old motor or in different places and couldn't reach.... there is a lot to consider when changing to a different type of motor....

but I am not saying, don't do it... I did it and it was a lot more work than just a motor swap... but I prefer a diesel motor over gas on the boat... also I get a break on my insurance for having a diesel motor vs a gas motor... also my diesel motor seems to be quieter than the other gas motors I have heard running on other boats...

sincerely
Jess