Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  

Powermax 4041 Rebuild or Repower?

Recommended Posts


Starting to think about restoring my 4041

the onan Cckb runs ok but blows some blue and the compression 

is only 90 pounds each side.

anyone rebuild recently ? What do you think it would cost?

carb is new ,muffler is ok ( not great)

i am guessing I would need 

gaskets, over size Pistons , rings 

boreing out the cylinders

Do I need new connecting rods ?


not sure what else?

i see that small engine warehouse would be about $1900 with shipping for a new 23hp with conversation kit

what are your thoughts what is your experience 

thanks for you help Gary


Share this post

Link to post
Share on other sites

I am pretty sure to rebuild the Onan would cost more than to repower with a brand new Kohler Commad with higher horsepower.  Onan's are ridiculously expensive to rebuild.  If you want to keep it original, than be prepared to spend some money.  I would look into either a Kohler Command 25 HP or if you want to stay cheaper, look into a Harbor Freight 20HP engine that sell for around $800.  There are other members who have more experience on these Onan's that will comment

Share this post

Link to post
Share on other sites
equipment guy

I hunted down a decent running used Onan from a power max, tuned it up, and installed it.  In my spare time, I have been hunting down reasonably priced parts to  rebuild my original engine. Used engine has a little better than 105 psi compression, and has been running great for the last year and a half.  I figure in the end, I will be into a rebuilt engine, and a good spare, for about 1500.00.   I use this tractor almost daily, for numorous chores, and prefer the fit function, and weight of the Onan.

Share this post

Link to post
Share on other sites

Check your engine before you start buying new parts. Not all engines need new pistons , rods and so on .

if everything checks out ok  you may only need rings , gaskets and the valve reground.

only reason I see for complete rebuild would be a total restore.

I rebuilt a CCKB couple years ago and cost me $300, rings, gaskets and rod bearings, mains were unavailable at time.

Just my $.02

Share this post

Link to post
Share on other sites

I agree with lloyd see what you have to work with first with the onan.

 A kohler command 25 will not fit with out trimming the hood and you wont be able to use rear pto because of the phisical size of the engine it has to sit high enough to clear frame and jackshaft for hydro drive. this puts the crank shaft around a inch higher than the onan and unable to use rear pto shaft. this is what i had to work around when i put a command in a 620 a few years ago.

the briggs kit from small engine warehouse is the way to go if you want a new engine. they are cheeper to maintain and eazy to get parts for unlike the onan.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Who's Online (See full list)

    • PGL
    • Bill725
    • RAC
    • Brian Shires
    • Bird76Mojo
  • Today's Birthdays

    1. 720nut
      (66 years old)
    2. Joe Scann
      Joe Scann
      (79 years old)
  • Recent Status Updates

    • Paul M.Murphy

      Paul M.Murphy

      Hello glad I got on this site. I hope to upload a couple of photos of my Simplicity Broadmoor 
      Model 707 Tractor. I have replaced all the belts on it and installed a new ignition switch.
      Have a mower deck which was in poor shape , repaced a couple of bushings and welded the
      deck where there was some holes. The tractor and mower deck came from a friend and the 
      mower deck metal was getting pretty thin. Some new metal was put in it and we also undercoated the underside of the deck. This was done by my friend Greg Toulman.
      I have not put the mower deck on the tractor yet, waiting for Greg to come home and give me a hand. Can you please tell me if there is a manual for the mower deck and where I could get one.
      I would also like to get some moon wheel discs as well.
      I will try and down load some photos of the tractor when my wife shows me how to. 
      I really love driving this tractor and also how well it is made compare today's tractors, especially the flexible rear end and the rollers.
      Tell the next time 
      · 9 replies
    • jbrooks

      jbrooks  »  Talntedmrgreen

      folowing  this from a link at the downloads.  I just rescued an AC 920 with the lambodini diesel. I can' t download  yet .  Where did you find the PDF copy you posted. . I would like to figure out how to adjust the injection pump. 
      I assume it's a bosche, correct
      · 0 replies
  • Adverts