Onan vs Kohler

[Dawgman 2]

Good afternoon.  Kinda new to the Wheel horses as I have always been a vintage Sears collector.  My question is, what engine is most preferred in the Toro Wheel horses, the Onan or Kohler?

[pfrederi 17,147]

Welcome.  Your question will certainly lead to an interesting discussion....both have their supporters...

 

My choice is Kohler because parts are much more readily available and less expensive....

[WHX?? 46,739]

 Dawg

Most here are going to say Kohler. Mostly because that is just a more popular motor and given the quirks and parts prices/availability of an Onan. 

Still the power and sound of a well running Onan ... nothing like it. 

[bottjernat1 2,189]

Like said above Kohler but my onan does sound pretty good! 

 

[roadapples 6,981]

Kohler .. easier to work on...

At least the singles...

Edited October 19, 2020 by roadapples

[ebinmaine 63,113]

Welcome to the site!

 

 

Either brand is quite subject to previous owner maintenance history.

 

I haven't yet owned any Onan engines but I understand from others that the power of an Onan 20 is tough to beat. Biggest thing is to keep them clean and cool and well maintained.

 

Personally I have a leaning preference towards the Kohler engine line both singles and twins.

 

As stated above already the parts availability for a Kohler single engine is excellent both new and used.

Easy to maintain, easy to repair. Ounce for ounce they've got quite a lot of grunt in comparison to others.

[squonk 38,916]

I had an Onan pto side bearing retainer loosen up with out warning dumping a couple of qts. of oil out before I saw it. If this happen blowing snow I'd have been done for. No more Onans for me. 

[SPINJIM 1,978]

I recently rebuilt an Onan P518.   A few reasons I don't like Onans:

   1,  If you want to adjust the carb, you have to remove the muffler and air cleaner.  Ever try adjusting a carburetor needle while the engine is running without a muffler?  I ended up drilling a hole in the muffler bracket so that I could get a long screwdriver into the adjustment.   

   2.  Want to check the gap on the valves?   You have to remove the muffler, the intake manifold and carb, and a lot of the wiring.

   3.  Since Cummins Diesel has taken over Onan, they have been more difficult to deal with, and more expensive.   They refused to accept my order for some parts because it was the week before they were shutting down for a month for a company-wide vacation.   They said I didn't know what I wanted, even though I got the part numbers directly from their website.

   4.  A twin cylinder Kohler sounds just as good as an Onan, and it doesn't overheat the rear cylinder.

 

Just my opinion based on recent experience.

   Jim

[pacer 3,159]

Pretty much what the others say---- parts availability and cost of same, the Kohler has it hands down, and as far as 'power' the the big twins - 16-20hp - of them both are about the same. 

 

I have both, a 16 Onan and a 20 Kohler and I 'm afraid to admit it but when that Onan is up on the throttle (and well tuned)  ----- well its just a fine sound!

[johnnymag3 2,441]

K O H L E R .......

 

[richmondred01 2,205]

Kohler single either the k series or magnum. 
onans require more maintenance and the parts are very expensive. 

[WHNJ701 4,164]

2 best sounds an ONAN makes....

 

1. When it's says good bye because you sold it to some sucker on Craigslist

 

2. When it says ouch as the dude at the scrap yard crushes it.

Edited October 19, 2020 by jabelman

[richmondred01 2,205]

5 minutes ago, jabelman said:

2 best sounds an ONAN makes....

 

1. When it's says good bye because you sold it to some sucker on Craigslist

 

2. When it says ouch as the dude at the scrap yard crushes it.

wow. I’m a Kohler fan but that may be a bit harsh. 
I would agree it we were discussing predator engines. 

[tom2p 2,393]

few engines are as reliable as a single cylinder Kohler 

 

not sure about the twin cylinder Kohler - I've heard/read good things but also read the early 17 twins had issues (and JD recalled them)

 

the Onan twins are great runners; but they have maintenance issues

 

I have one Onan powered 416-H with around 1000 hours that has been problem free since the day I purchased it (from the original owner)

 

other than filters and oil changes it has not been touched - zero nada nothing ;  no valve adjustments, no disassembly to clean cylinder head or cylinders, no decarbonizing of combustion chamber, no carburetor cleaning ... nothing 

 

it gets used 2-3 hours at a time - non stop ; I've cut on 40 degree days, cut on 90+ degree days, cut in the rain 

 

Wheel Horse 416-H is probably the best vehicle I've owned 

 

I also have a great running 312-8 - but the 416-H is on another level compared to the 312-8

 

I think so highly of the 416-H I got another one because at 1000 hours (with lack of proper maintenance) it might be ready to expire 

 

Edited October 20, 2020 by tom2p

[WVHillbilly520H 10,369]

2 minutes ago, tom2p said:

few engines are as reliable as a single cylinder Kohler 

 

not sure about the twin cylinder Kohler - I've heard/read the early 17 twins had issues (and JD recalled them)

 

the Onan twins are great runners; but they have maintenance issues

 

I have one Onan powered 416-H with around 1000 hours that has been problem free since the day I purchased it (from the original owner)

 

other than filters and oil changes it has not been touched - zero nada nothing ;  no valve adjustments, no disassembly to clean cylinder head or cylinders, no decarbonizing of combustion chamber, no carburetor cleaning ... nothing 

 

it gets used 2-3 hours at a time - non stop ; I've cut on 40 degree days, cut on 90+ degree days, cut in the rain 

 

Wheel Horse 416-H is probably the best vehicle I've owned 

 

I also have a great running 312-8 - but the 416-H is on another level compared to the 312-8

 

I think so highly of the 416-H I got another one because at 1000 hours (with lack of proper maintenance) it might be ready to expire 

 

I bought my 1st 520H brand new and other than the valves adjusted once and the ignition module just basic maintenance and much like you mowed grass in the 90°+ and blowed snow in the negatives definitely a 4 season machine in my book, I have been around single and twin cylinder Kohlers in Cub Cadets but never had the seemingly endless power band of the Onan...    Steiner (articulating tractors precursor to Ventrac) were powered by Onan flat head horizontally opposed twins as well as Case/Ingersol and the bigger Simplicity/Allis Chalmers the top Cub Cadet 982 and JD 318/420 so that should say something that top line models were Onan powered before the EPA basically shut them down for not meeting emissions and why Kohler came out with the Command series OHV singles and V-twins... I love my Onans even when they are a bit contrary.

[tom2p 2,393]

7 hours ago, ebinmaine said:

Welcome to the site!

 

 

Either brand is quite subject to previous owner maintenance history.

 

I haven't yet owned any Onan engines but I understand from others that the power of an Onan 20 is tough to beat. Biggest thing is to keep them clean and cool and well maintained.

 

Personally I have a leaning preference towards the Kohler engine line both singles and twins.

 

As stated above already the parts availability for a Kohler single engine is excellent both new and used.

Easy to maintain, easy to repair. Ounce for ounce they've got quite a lot of grunt in comparison to others.

eb - include the Onan 16 also 

 

the power of the 16 is impressive  - so much that you can think you have a 20 

 

one reason might be the size (displacement) ;  I believe the P216 is around 710cc which is slightly more than the KT17 at 691cc ...  believe the P220 is 782cc

 

The Onans also generate more torque - and earlier (at lower rpm)

 

[richmondred01 2,205]

The Kohler kt17 series 1 had lubrication issues. The series 2 corrected the issues however, by then Kohler was having some major public relations issues regarding the KT line.

Therefore, they came out with the rebranded  M18 which had 1 additional hp, positive lubrication, filter, and electric ignition..

Great engines however, they have non adjustable valve tappets so the valves have to be fitted and stems ground like the k181 and lower models. 

[WHX?? 46,739]

Question @richmondred01, would an M18 be a drop in repower for a KT? 

[pfrederi 17,147]

19 minutes ago, WHX24 said:

Question @richmondred01, would an M18 be a drop in repower for a KT? 

  Bolt in would be the same but you have to rewire  and new ignition switch as KTs are battery ignition Magnums are Magneto

[Tgalo 118]

Just thought Id add my 2 cents... I have a 418 with a 18hp Kohler and a 520 with a 20hp Onan. Both with between 500-600hrs. Seems I'm always working on the 520 but the 418 never needs anything but gas. To be fair I don't know the history of either tractor so theres that but I do take good care of them now. No matter how tall the grass gets I cant hear the 520 bog. Never seems to run out of power. But I think I would prefer the Kohler if I had to pick...

T

[WHX?? 46,739]

5 minutes ago, pfrederi said:

have to rewire  and new ignition switch

That's the easy part for me..... it's the bolt in might challenge my skill set! 

Just in case I stumble on a good M18 or 20... Richmond has got me worried about my smoking KT again!

[pfrederi 17,147]

7 minutes ago, WHX24 said:

That's the easy part for me..... it's the bolt in might challenge my skill set! 

Just in case I stumble on a good M18 or 20... Richmond has got me worried about my smoking KT again!

Stay out of ditches and off steep hillsides and keep the oil a bit above teh full mark.  I have a series one that was pulled from my bothers JD317 because it leaked oil and smoked some.  had well over 2000 hours and i still use it annually to run my sweepster.  Smokes on start up but clears up after a couple minutes.

[richmondred01 2,205]

1 hour ago, WHX24 said:

Question @richmondred01, would an M18 be a drop in repower for a KT? 

See pfrederi response. 

[tom2p 2,393]

2 hours ago, Tgalo said:

Just thought Id add my 2 cents... I have a 418 with a 18hp Kohler and a 520 with a 20hp Onan. Both with between 500-600hrs. Seems I'm always working on the 520 but the 418 never needs anything but gas. To be fair I don't know the history of either tractor so theres that but I do take good care of them now. No matter how tall the grass gets I cant hear the 520 bog. Never seems to run out of power. But I think I would prefer the Kohler if I had to pick...

T

what work does the 520 require ?

 

is it stored inside ?

 

 

I've done nothing to my 416 and it has around 1000 hours 

and my maintenance was lax at times - did not change oil as often as I should - and run standard gas from the local sheetz (instead of better non-ethanol fuel)

 

but the original owner and I have always parked it inside 

 

park an Onan powered tractor outside - and all bets are off ... not good 

 

I have another 416 that just began to do a mysterious shut down thing - don't know the history on that one (and hoping it does not need an ignition module)

 

Edited October 20, 2020 by tom2p

[pfrederi 17,147]

Why anyone would spend $5,000 plus in 1990 dollars for a Garden tractor and leave it parked outside I do not understand....But they did/do and that is why there are no electrically complex 520's in my future...