Onan vs. Kolher

[Wheel Horse Kid 104]

Hi,

I know someone is has already asked a question along this line, but I was just wondering what the quality of Onan motors are that were put in the Toro Wheel Horse tractors?

Thanks!

[mavfreak 11]

Onan engines kinda got a bad rap when they first came out with there opposed twins, (JD 316) but as with any engine proper maintenance and cleanings thery will run for a very long time. The onan's in wheel horses seem to lose there valve seats in the rear facing cylinders but here again that could be avoided by blowing out the dirt and dust that collects on the rear cylinder. (maintenance)

I wouldn't be deterred from buying one they are good strong engines with good power.

[mavfreak 11]

this is a recent posting you may want to read. Do a search on here to read more about the onan

http://www.wheelhorseforum.com/index.php?...ndpost&p=247357

[Wheel Horse Kid 104]

Thanks for your help. I checked out the link and it was informative. :woohoo:

[8993-520 0]

Like mavfreak said keep the rear cylinder, well keep both of them blown out all the time and keep the debris off the outter flywheel cover as you are mowing also. It is where the engine gets a lot of its cooling air and if it is cloged it too can overheat the engine. And and interesting fack about the onan p series anyway dont know much about the others is that they fire both cylinders at the same time. Unlike a v twine on a single pin crank. This makes for a lot of torque. Ask anyone on this site who ownes or has owned a 520 what kind of mowing machine they are. Oh and about forgot I use to work for a mowing service many years ago and would see these motors go well over 4000 hours with good quality maintenance, and 8 to 12 hours 6 and 7 days a week.

[SAM58 30]

I have had two 520H's

1996 with 350 hours still use...

1992 with 1650 hours friend owns now.

both still running strong.

Just keep them clean, and serviced.

[nylyon-(Admin) 7,121]

I haven't looked at the hours on my Onan powered 416, but I've owned it since new in 1993 (1994 model year) and it's been a flawless motor so far.

[Rooster 191]

...And and interesting fack about the onan p series anyway dont know much about the others is that they fire both cylinders at the same time....

That is not entirely correct. All opposed twins ( Briggs, Kohler, Generac as well as Onans) fire both plugs every rotation, however only one cylinder is on compression so only one cylinder really "fires" every rotation. The torque of the engine comes from pure cubic displacement and cam profile.

They don't actually produce more torque than a V-twin, but they have a flatter torque curve than the V-Twins. This is why they do makes such excellent grass cutters. A V-twin relies on higher HP and Torque for maintaining RPM, when they bog they start losing power quickly. An Opposed twin, especially the Onan's, are not effected as much if they lose a few revs.

I think the best part of any 180* Opposed twin engine is how smoothe they run. The opposed cylinders naturally balance each other, this combined with the flat torque curve makes for a very smoothe and stable running engine.

Interesting note: Though most Opposed twins (Briggs and Kohlers) even highly modified can not hang with a well built V-twins, Lawn Mower Racers in certain areas have been quite frankly killing Very strong V-twins with the Large Cube Onan's and Generac engines!

[KB9LOR 4]

Got to post my 2 cents worth, do not like Onans, simple reason, they are owned by cummins, which they have them engines locked, meaning you have to buy MOST parts from them, not third party, waaay expensive!...I will stick to my one lunger Kohlers. jmo

[can whlvr 991]

no onans for me either,they dont have a good rap up here,so theres not many dealers,the closest shop to my house gets kohler parts every day,not that i need many ,i can get parts at probally 6-8 places in my small town

[8993-520 0]

Yes it is entirely correst. Any engine 2,4,6 etc that fires more than 1 or 2 cylinders makes more hp and torque than any given engine that fires less cylinders ie 1 vs 2. So the reason for the onan(along with a very flat torque curve )makes so much power and can handle more load is that they fire both cylinders at the same time. The onan put out 34 ft lbs of torque as apposed to all the others at 22 to 28. I looked these numbers up online so they may not be exact but they were all I could find at this time. Not that I am apposed to any other twin but I just like the power of the onan. I have a honda 24 hp vtwin repower on a 520 and it cant do what the onan 20 can.

[truckin88 104]

also the Kohlers were used in lots more equipment for a lot long time period, making parts readily accessible and cheaper....you can get kohler parts at a local napa, that said. Nothing flys around like an onan powered 520 or a 416.... Kohler had some rarer horses, that are awesome, is the 414 and 416 Kohler K's and M's those are torque monsters. I would buy either as long as it runs good and was maintained.

[nylyon-(Admin) 7,121]

I love my Kohler 414-8 and my K-series C-160, but neither come close to the power, quietness and smoothness of the Onan 416-H, not even close. I can't comment on parts since I had been able to get anything I needed from Toro no issues.

[can whlvr 991]

i do agree that when an onan is running good they are powerfull,its the ford-chevy-dodge thing,its a good thing we all like different things

[Hydro 130]

There's nothing sweeter than the sound of an Onan at work or at idle after a cold start!

When they are running, they are the greatest. When they are not, you better have deep pockets! :thumbs2:

[Forest Road 594]

I owned a 520 with 100 hours for about a week. Swapped a friend for a 314h with 180 hours. The 520 sat so long the carb was shot. $300+ and it took me the better part of an hour to get at it. I can yank a kohler carb and rebuild it in about an hour for about $30.

The only reason to have an Onan is for that 60" deck. Or if you want to go a little faster with a snow blower.

My friend is a toro dealer. He completey repainted the tins on that 520. It looks and sound awesome. But I still don't want an Onan. Although I'd take a 520 with a bad motor. Love the front axle and geared steering!

[Herbl 10]

I thought I would put my 2 cents in on this topic. I own 3 520H Wheelhorses, I love them and think they are great tractors and yes, the carb is a pain and you need to keep them clean constantly but those Onans give some power. I recently (good deal) purchased a Simplicity Sunstar, it has a 20hp Kohler Magnum, yes I've been told that is another great engine. I had to rebuild the carb on that too, I didn't see much difference in $$$ to repair. I also had to do other things to the engine to get it running to my satisfaction (new oil breather assembly). The Sunstar 20HP has a 2 speed trans and a locking diff, truly a nice tractor. Now to the point I was getting at, when I look at rebuilt engine from the guys who do them, I really don't see the difference (maybe $100) between short blocks. I think a lot of people with single cylinder Kohlers are comparing repair costs with the Onans and saying they are high bucks but we really need 2 cylinder to 2 cylinder engines to be fair. By the way the Onan is a brute compare to the Kohler but the Kohler is easier on the gas and still powers a 60" mower deck without a problem. Now ask me what I think overall about the Sunstar and the 520's and that's a story for another time....

[shorts 182]

My opinion is that they are both only as good or bad as the maintainence they recieve, I'm partial to the kohler singles because I'm mor familiar with them and they are easy to work on. With that being said if you need more power the onans are well made and reliable, you have to be religous about keeping the cooling fins clean but the same is true for for all of the air cooled engines.

Off topic, if you want a real power monster use an old style wisconsin twin or v4' they are huge and expensive but reliable.

[can whlvr 991]

we had a skid steer at the place i used to work,it had the big wisconsin in it and it ran for years with no problems,the hydro pump died before the engine,had them on our cement mixers too,it seemed when they died they really died,usually self destructed,but reliable till then(kinda like my honda,s )

[kpinnc 10,736]

I think a lot of people with single cylinder Kohlers are comparing repair costs with the Onans and saying they are high bucks but we really need 2 cylinder to 2 cylinder engines to be fair.

True, but some things should still be similar. That said, Onan parts are extremely expensive- and that is IF you can even find them. I love my Onan on my 518-H, but it will NOT be rebuilt when it goes out. It will be re-powered with something else.

I can rebuild a Kohler carburetor for $13 with genuine Kohler parts. An Onan rebuild is over $75.

As has been said before- a twin-cylinder engine is very strong and smooth, but it is also far more complicated and expensive to maintain. If you are mechanically inclined, then an Onan will be great. If you need something a bit simpler to maintain, then get a single cylinder Kohler-powered machine.

My two cents... :thumbs2:

[mavfreak 11]

we had a skid steer at the place i used to work,it had the big wisconsin in it and it ran for years with no problems,the hydro pump died before the engine,had them on our cement mixers too,it seemed when they died they really died,usually self destructed,but reliable till then(kinda like my honda,s )

I don't put the wisconsin in the same category they just seem to run forever. A farm I worked at had a wisconsin to run the pumps at the milk house. That thing was so old and never quit. Also had one in the skid steer there also And same as you said it seamed everything else was going bad and it just kept going. Although both these were liquid cooled.

Just my 2 cents worth :thumbs2:

[Jim_M 178]

If you think Onan parts are expensive and hard to find, go buy some Wisconsin parts. But like others have said, they run forever.

I have had good luck with Onans, can't really complain about them. They're now owned by Cummins and the parts prices have gone up, but like any other thing, take care of it and it will take care of you.

[mavfreak 11]

If you think Onan parts are expensive and hard to find, go buy some Wisconsin parts. But like others have said, they run forever.

I have had good luck with Onans, can't really complain about them. They're now owned by Cummins and the parts prices have gone up, but like any other thing, take care of it and it will take care of you.

couldn't agree more! :thumbs2: