Onan 16HP (520H) engine with broken rod to Kohler Engine K241

[Tim Ziethen 3]

Does anyone know what is required to swap out the Onan engine with broken rod on my 516H and drop in an good working engine from my 310-8 parts tractor?  I have read all the posts I can find but the ignition and charging circuit and wiring compatibility is not clear.  Thanks for the help!

 

 

[gwest_ca-(File Mod) 11,040]

Welcome to the forum.

 

What is the Kohler spec number on the 310 engine?

 

The 516-H should be a 1988 tractor model 31-16OE01

 

Where does the 520-H enter this combination?

[Tim Ziethen 3]

Sorry it does not - my mistake on typing!

 

The tractor is a 516H with what I believe is a broken rod - engine running on one piston now.  I have a 310-8 parts tractor - do not have the engine spec right now, will have to post it later but it is a 10hp Kohler k series that I believe is a k241s that runs very smoothly.  So I was hoping I could take the 310-8 engine and put it in the 526h at least for now while I tear down the Onan to see if it can be salvaged. Only plan on mowing with a 42 inch deck.

 

Again - thanks for any and all help!

[Tim Ziethen 3]

Also the seat pan was painted on the 310 and the serial number is not readable - have to take a picture on the engine and confirm the series if possible.  You are correct on the 516h model number.

Thanks

[Maxwell-8 4,275]

7 minutes ago, Tim Ziethen said:

Sorry it does not - my mistake on typing!

 

The tractor is a 516H with what I believe is a broken rod - engine running on one piston now.  I have a 310-8 parts tractor - do not have the engine spec right now, will have to post it later but it is a 10hp Kohler k series that I believe is a k241s that runs very smoothly.  So I was hoping I could take the 310-8 engine and put it in the 526h at least for now while I tear down the Onan to see if it can be salvaged. Only plan on mowing with a 42 inch deck.

 

Again - thanks for any and all help!

Sure is possible.

 

Hydro may but a higher load on it.

You lost compression on that cilinder? 

[Tim Ziethen 3]

Bought tractor as "running" but when I picked it up the seller clarified that the piston on the inboard side (by the tower/seat) was not moving so I suspect a broken rod.  What is surprising is the engine was/ is running "fine" on the single cylinder.  Rough and shaking but running.  I have heard of rods (always the rear one) breaking/snapping on this engine with little or no other damage - hoping that is the case. This is the one without a pressurized oil system and no oil filter, only oil slinger.

 

Anyway - for now I would love to swap the engine from the 310-8 just to have a working tractor and the only thing I am planning on using with this is a 42 inch deck and maybe a snow blade.  It has the Eaton 700 hydrostatic transmission on the 516H. 

 

I do not know what is required or compatible from a wiring/charging voltage point of view - hearing that the K series and Onan were very different wiring.  Has anyone done this type of swap?  Thanks

 

[Achto 27,562]

2 hours ago, Tim Ziethen said:

I do not know what is required or compatible from a wiring/charging voltage point of view

 

Most important thing to know. Are both engines battery ignition or magneto ignition? If they are both one or the other that will simplify things. If you have one of each then you will have to change out the ignition switch. A switch with an "M" terminal is for a magneto ignition, A switch with an "I" terminal is for a battery ignition. You may also have to reconfigure plug for the ignition switch if you have to change it. I would down load the manuals for both tractors from this forum and compare the wiring diagrams to see what will need to be changed.

Edited January 13, 2022 by Achto

[Tim Ziethen 3]

Thank you - hoping a member did this and can weigh in on steps

[oliver2-44 9,726]

The hydro will suck 2 hp from that 10 hp, so you will be left with about 8hp to turn a deck, 8hp is really stretching it to turn a 42" deck.

[RED-Z06 2,221]

Yeah 42" is pretty much all a 10hp will like, my K241 with the 42" deck is running no less than about 40% governor at all times and thats with the 8spd, not sure it would do it with a hydro also.

[pfrederi 17,701]

Over the years 310-8 came with K-series then Magnums.  What spec number is your donor.

[roadapples 6,983]

[Tim Ziethen 3]

Sorry for delay - the donor engine is a kohler k241s spec 46863

Thanks for any help!

[kpinnc 11,995]

4 hours ago, Tim Ziethen said:

k241s spec 46863

 

That spec at least appears to be correct for the 310-8 line of tractors. That being said, you're gonna have some modifications to do to make a successful swap. Will it work? Absolutely. Will it be easy? Depends on your electrical skillset and willingness to modify the electrical system. You're also gonna have to decide how much safety interlocks you're willing to wire up.

 

My opinion only- physically swapping engines should be easy. Remove the Onan and mounting plate, and the Kohler should bolt right in. Thats where the similarities end.

 

Again my opinion only: I would carefully remove the factory wiring harness and start over. You'll need a keyswitch that works with a 12v coil and points ignition. The electrical fab work required to make the engine run is fairly simple. Safety switches being implemented will be at your discretion. 

 

And the last thing to consider: as has been previously said, you are going to be limited with what that 10hp will pull. Any powered implement will max that leftover 6-8hp in a hurry. It's plenty to drag non powered stuff, but mowing with 36-42 decks will be all it will do. 

 

The P216 may be expensive to repair, but likely worth it if the block and crank is undamaged. It's a bit more rare for the 16 to throw a rod than the 20hp. I hope the valve seats weren't the cause, but even that can be fixed by a good engine shop. You won't know until you get in there to see what broke and why.

[Tuneup 1,433]

4 hours ago, kpinnc said:

<snip>

The P216 may be expensive to repair, but likely worth it if the block and crank is undamaged. It's a bit more rare for the 16 to throw a rod than the 20hp. I hope the valve seats weren't the cause, but even that can be fixed by a good engine shop. You won't know until you get in there to see what broke and why.

 

Yeah, what he said! You might have less trouble repairing that Onan than retrofitting a 10HP. Oh, I have that same engine on my 516H. No filter but it is pressure lubricated. Unlikely to have valve seat issues thanks to the no filter but, a rod and maybe a piston with a quick hone on the cheap - maybe easy. Worth a look-see, especially in the off season in MD.

[clueless 2,986]

On 1/12/2022 at 8:41 PM, RED-Z06 said:

Yeah 42" is pretty much all a 10hp will like, my K241 with the 42" deck is running no less than about 40% governor at all times and thats with the 8spd, not sure it would do it with a hydro also.

Down here especially with centipede grass cut 1 1/2 to 2 1/2 inches an 8 hp with 42 RD deck works fine, the SD takes more nut to blow the clipping out the side. Cut my 3/4 acre for fourteen years with a B80 4sp with a 42 RD deck. Clint (Anderson's Equipment) sold WH's here for many years and was a WH district sales rep, sold many 8 hp WHs with the 42" RD, he told me the engineers at WH told him with the shorter grass down here the 42 rd would work fine. They obviously didn't know about Pensacola Bahia grass  when that stuff gets high and thick you need a SBC to cut it and depending on how thick it is, that may need to be punched out. . 

Edited January 15, 2022 by clueless

[RED-Z06 2,221]

14 minutes ago, clueless said:

Down here especially with centipede grass cut 1 1/2 to 2 1/2 inches an 8 hp with 42 RD deck works fine, the SD takes more nut to blow the clipping out the side. Cut my 3/4 acre for fourteen years with a B80 4sp with a 42 RD deck. Clint (Anderson's Equipment) sold WH's here for many years and was a WH district sales rep, sold many 8 hp WHs with the 42" RD, he told me the engineers at WH told him with the shorter grass down here the 42 rd would work fine. They obviously didn't know about Pensacola Bahia grass  when that stuff gets high and thick you need a SBC to cut it and depending on how thick it is, that may need to be punched out. . 

When i had my 310-8, .030over fresh engine, i put a 36"rd deck on and it never felt it even in 6" grass.  I put the 42sd on and it was a struggle, poor engine spent alot of time near 70% or 80% governor.  I thought maybe it was the rebuild...down on power.  When i got the low use C-100 i figured it would be more powerful being original.  Nope...if the deck is on the governor is open, head temps soar from 200⁰ to 266⁰ before it ever sees a blade of grass.  

 

Thr 16hp Onan never touches the governor...itll smoke thru the belt first 

[Tim Ziethen 3]

sounds like I should tear the 16hp Onan down first to see extent of damage - would love to rebuild - just reading how expensive parts and rebuilds are but will try that first - thanks to all!

[pfrederi 17,701]

14 hours ago, Tim Ziethen said:

Sorry for delay - the donor engine is a kohler k241s spec 46863

Thanks for any help!

 

 

Fortuneteller the Kohler web site has only very limited info about that spec. and my parts manual doesn't cover it at all.  Other research indicates you may have the 3 amp unregulated system or maybe a 15 amp system.  Is there a voltage regulator on the 310 tractor??  If not you have the 3 amp system.  You will have to rewire your lights to run off 12v AC direct from the stator (lights will only work engine running).  I do not know what other electrical requirement a 516 onan would have but 3 amps isn't a lot once you are running the ignition system...

Edited January 15, 2022 by pfrederi

[RonnieB2nd 33]

Some Kohler engines have a dash and it's different