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Final Verdict -- Case 448 w/ Onan 18 HP . . . Rebuild or Repower?

onan 18 b48m rebuild repower

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#1 Case448 OFFLINE  

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Posted December 08, 2015 - 09:04 PM

Got my project tractor running.

 

Has good power, runs pretty good. But, lots of "clattering" -- sounds like a loud valve clatter, but I just had a valve job and adjusted the valve lash, so that can't be whats causing it.

 

I would say this loud "clattering" sound is an indication of my biggest problem with this motor. Any idea what could be causing it?

 

Currently considering whether I should rebuild this Onan 18 HP (B48M), or repower with a Vanguard, Honda, or Kohler.

 

Any and all thoughts appreciated...


Edited by Case448, December 08, 2015 - 10:18 PM.


#2 propane1 ONLINE  

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Posted December 08, 2015 - 09:23 PM

Send that Onan engine to me, for free, and you put in what ever engine you would like. Lots of makes and models out there. That will be your answer.

Hehe, just kidding ya. Hard to say what to do. I have no answers. Hope you find out something. Noel

#3 Gtractor ONLINE  

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Posted December 08, 2015 - 09:55 PM

You need to bust it open and find out whats wrong before it grenades or you'll have some very expensive scrap.



#4 Eric OFFLINE  

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Posted December 08, 2015 - 10:28 PM

Just because you did the valves does not eliminate it as a problem, I have caught myself having to redo some motors because contrary to what I would like to think I am not gods gift to mechanics! Just a thought but we don't always get it right the first time. Good luck.

#5 Oldford OFFLINE  

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Posted December 08, 2015 - 11:37 PM

Did you try this guy he is an onan specialist,

http://boomersonanparts.com/

He also knows case tractors, good luck



#6 Rock farmer ONLINE  

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Posted December 09, 2015 - 02:41 AM

Have you redone the engine mounts?

#7 chieffan ONLINE  

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Posted December 09, 2015 - 09:36 AM

If it is a clatter sound it is more than likely the valves.  A rod or piston slap would have a duller more of a thump sound. 



#8 bryan 110 OFFLINE  

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Posted December 19, 2015 - 07:47 PM

Only cool thing about a onan is they will literally work itself to death. We had a bobcat years ago with a onan 2 banger and it kept going till the block split in two. I would keep it and see what the noises are and fix them.




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