Onan CCK round head vs UN opinion please

[Dan H]

On the horns of a dilemma. Contrary to popular belief, one can have to many gen sets. 30 years ago with a young family in the country and older relatives, we had a urgent need for hydro. Than came grandchildren and hydro outages of a week. Always had at least 3 CCks, 2 round heads and 1 UN. Now with 4 round heads and 4 UNs (and 1 JB 5k round head and 1 AJ) I wish to downsize. I need to concentrate on 1 design only. Both styles have very obvious good and bad points that I am aware of. Everyone has a opinion, be it right or wrong. I am hoping with this post I can gain some more insight into the 2 designs for reliability and abuse. What started this line of thinking was the post earlier this week on the history of Onan where they mentioned a better gen set for RVs that would start AC better. Thinking about it the UN always started my old 220 compressor a lot nicer. Thanks in advance for your insights, Dan

[Motorhead]

The UN seems to turn the engine over better than the round head for starting.
Obviously, the square UN head is newer so parts availability should be better and that design was used in several models. I wouldn't have any issues if they were mine to take the best and quietest engines be they newer or older and pair them up with the best of your generator heads. In other words, take the best of your components and match them up together.

[Kevin K]

I would say go with the UN generators. The starting current is less, the weight is less, and they are easier to get parts for. For example, the brush holders on the round head generators are getting hard to find, and pricey when you can find them.

I have two round head CCK's and one square head CCK. Any CCK's I purchase in the future will be 5CCK's with a UN generator and reconnectable to 120/240 or 120 only.