520 HC - the Onan 20HP is dead - is there a replacement engine??

[Paul_Aussie 5]

Hi all,  My old 520 HC (1988 I think) had died due to the engine my mechanic tells me (not worth fixing - also a problem getting parts here in Austrlia) - does anyone know of a replacement engine that could work with the 520 HC please?  The mechanic says no engines made in that configuration now - (sorry if this offends the true believers in that I am thinking of changing the original engine - also I am not mechanical at all - so please don't be offended if I reply with a ???, or maybe not at all to your specific suggestions/ideas) - thanks again - Paul 

Edited May 11, 2016 by Paul_Aussie

[MalMac 1,332]

I believe Small Engine Warehouse web site has a Briggs Vangaurd set up as a repower option. There have been others on here that have used different motors also.

[AMC RULES 37,144]

http://www.smallenginewarehouse.com/Repower-Old-Equipment/Wheel-Horse-520-8-Category/

[cleat 6,796]

I just keep finding more used 520's that run good and buying them up for spares.

 

I am currently in negotiations on another one. Usually cheaper to find a good running used tractor especially if you don't care what condition the rest is in than to buy a new engine.

 

Also you know it will be a direct bolt in.

[new horse 44]

just out of curiosity, I looked at small engine warehouse's repower kit for a wheel horse,     $1650.00 plus shipping, that's just insane!!! 

[Blue Delta 35]

Paul, 

 

What is exactly wrong with your Onan, ALOT of the parts are still listed as available from Toro Australia. How many hours do you have on it?

 

[Paul_Aussie 5]

Hi All, - thanks heaps for the comments to date - much appreciated.  One cylinder was not functioning - it needs to be re chromed.  Suggested by the mechanic that to do one, then you should do both - expected to cost up to $1,500 for each one to be done.  I have had this 520 for 14 years - it is a lot like me - looks old and not worth much!  the reality is it has very rarely let me down, is a great working machine and I still need something like it to do all my jobs around the place.  What I have seen as a replacement almost brings tears to my eyes in terms of cost to get something as strong as the 520, or quality when I look at what we can realistically afford.  (I must admit mine looks nothing like the photos I have seen on this site at all - very impressed)

thanks AMC (& Malmac) - I will take that info to the mechanic to see if we can get it in Australia here - and if he is confident of doing the job.  Thanks to Blue Delta too - my mechanic is a dealer for Toro - and has been working on them for some 18 years and tells me he has checked out what you can/cannot get from Toro. (Cleat - not being rude here - but you either have way too much time on your hands or you a certified nut - fantastic looking machines - whilst I am not mechanically minded like all/most seem on this site, I do recognize quality and that is all I see in my 520, and such is confirmed by what I see in your photo)

thanks again to all - Paul

Edited May 12, 2016 by Paul_Aussie

[AMC RULES 37,144]

                                    

Put any thought into obtaining a "used" engine as a replacement? 

You might be suprised what a "wanted" ad...     

here in the classifieds will get you. 

http://www.wheelhorseforum.com/classifieds/wanted/

[Paul_Aussie 5]

thanks Craig - just put an ad in now - see what happens (fingers crossed) - also re earlier question from Blue Delta - sorry no idea re hours - gauge has not worked for the last 14 years!

I like this site - whilst not mechanically minded at all - all seem very helpful and that (certainly most are certifiably mad re their passion for their machines too!!!!!!) - Paul

Edited May 13, 2016 by Paul_Aussie

[Horse46 519]

13 hours ago, Paul_Aussie said:

thanks Craig - just put an ad in now - see what happens (fingers crossed) - also re earlier question from Blue Delta - sorry no idea re hours - gauge has not worked for the last 14 years!

I like this site - whilst not mechanically minded at all - all seem very helpful and that (certainly most are certifiably mad re their passion for their machines too!!!!!!) - Paul

You are obviously very observant, they're all bonkers on here, don't be suckered in though, they try to give you the disease of collecting. Sshh don't tell em I said that!

[onanparts.com 181]

On 5/12/2016 at 7:27 PM, Paul_Aussie said:

Hi All, - thanks heaps for the comments to date - much appreciated.  One cylinder was not functioning - it needs to be re chromed.  Suggested by the mechanic that to do one, then you should do both - expected to cost up to $1,500 for each one to be done. 

Hi Paul,

Your Onan cylinders can't be re-chromed as they were never chromed when new. Your P220G has Cast Iron liners that are cast into the Aluminum block. They are not replaceable but can be resized/bored to three different oversize pistons. +.010  +.020 & +.030

 

A cylinder described as "not functioning" could be a number of issues. Broken con rod, burnt or out of adjustment valve, worn rings etc. It would be interesting to know more detail/info on exactly what the mechanic means by non functioning? 

[onanparts.com 181]

According to an older post here, the Onan P220G-I/10541B was one of two Onan P220G engines used on the 520-HC. Here is the Onan unit Production Order for the 10541B spec.

[JackC 617]

The 520-HC is a special member of the Wheel Horse family.  It is the grand father of the 520 Series and it will out run any other 520.  I agree with cleat. I would look for a used 520 and have your mechanic do a simple engine swap and keep the high capacity air filter off the old engine.  Your old engine can also be a source of other valuable spare parts. Rebuild is too expensive and if you put anything else in it you will not have a genuine 520-HC and the wheel horse gods who are watching over all of us will dock you a few points. JMHO

[mikekot3 92]

I bought the small engine warehouse conversion kit for my 416 onan to a briggs and Stratton vanguard v-twin 23 hp it works well and is a nice kit.

[Docwheelhorse 2,683]

Find a Kohler 16 one lunger and swap it in.... it will run for 1000 years and never lunch the exhaust seat or burn out the $10,000,000.00 coil or... or... or... the Onan's day has come and gone. Yah its a big burlly motor---just too many expensive parts.

 

That's my .02. I had a 520-8 and just couldn't stand the carb fluttering and constant maintenance. I have a 416H that I pulled out the blown up Onan and put in a K341... runs minty and isn't that hard of a project.

 

Tony

[djohn24 10]

Any updates Paul? By your mechanic saying "   it needs to be re chromed " What he is saying...your cylinders need honed. At least that's what my thoughts are. And $1500 a cylinder??? Is that Australia money?

[ohiofarmer 3,305]

 For what is possible look here.http://www.harborfreight.com/22-hp-670cc-v-twin-horizontal-shaft-gas-engine-epa-61614.html

The biggest challenge is the one inch shaft size needs to be bushed up bigger to fit the clutch drive. i have not done the 22HP conversion, but have had success with the 420 predator also from Harbor freight. It pulls OK even with a 48' deck. There were enough tapped holes in the engine that mounting the cone clutch was not a big deal to me. There has been some mention of needing an electric clutch, but my engine bearings held up fine. I did raise the engine up 1.25" to match the pulley height. It can be done, but I just leave the hood off because on the 420, the exhaust and air cleaner have clearance issues. But only 350.00 for a functioning 520 is a steal.

 

 Now a word about the warranty. Harbor Freight warrants the engine for 3 months, but you can buy an extended one for fifty bucks that extends it to two years plus the original ninety days. I usually run the engine for two months and then buy the warranty. If the engine blows, or even leaks some oil [they do seep a bit] or just the electric start pukes, they give you a brand new motor. So you get a brand new engine and again buy the warranty for 50 bucks, and keep changing engines every two years. i call that a pretty good warranty. At that point, you are leasing the engine for $25.00 a year. My engine, the 14 HP 420, lost the electric start pretty quickly, but it was no biggie using the recoil start for the remainder of the warranty period. It always started on the second pull, so I figured why even trade it in early? 

 I have another Onan making noises in the garage queen 416-8 that i may swap out and take the time to fab up a revised muffler and reconfigure a different air cleaner for a better looking tractor.  Here is my engine

http://www.harborfreight.com/13-hp-420cc-ohv-horizontal-shaft-gas-engine-epa-60340.html

 Still, the old Raider 10 build quality puts both these newer horses to shame. Of course, I cannot recommend a new Harbor Freight vs. a decent used Kohler, but it can and will get you by until you can find one.

Edited July 13, 2016 by ohiofarmer

[bowtieguy 334]

OH farmer....your "biggest challenge" is really not a challenge....I bought an Oilite bearing  (www.oilite.com) pn 60695K7,,,,cut a slot in it for the keystock and it is an easy fix to go from 1" to 1 1/8" and use the original WH pully off the ole engine (mine was a series I Kohler twin) from a C-175.....then I elected to use an ole WH electric clutch which fit right up with no problem

Of course you will need some "offsize" key stock....which I bought from McMaster Carr......bearing and keystock was less than 10 bucks.

 

I don't know how long the HF will last....but the ole C-175 w/48" deck is now one badass mowing machine....you can find my other comments about the swap on a previous post.....as soon as HF runs the 22 hp engine on sale again for 500 bucks, I'm going to do another C-175.

 

Of course that's my 2 cents worth and I'm not voting for crooked Hillary

[Pappy 4430 8]

On 5/20/2016 at 3:59 PM, Docwheelhorse said:

Find a Kohler 16 one lunger and swap it in.... it will run for 1000 years and never lunch the exhaust seat or burn out the $10,000,000.00 coil or... or... or... the Onan's day has come and gone. Yah its a big burlly motor---just too many expensive parts.

 

That's my .02. I had a 520-8 and just couldn't stand the carb fluttering and constant maintenance. I have a 416H that I pulled out the blown up Onan and put in a K341... runs minty and isn't that hard of a project.

 

Tony

Does that 16 hp run a 60" deck ok ? 

[Docwheelhorse 2,683]

With sharp blades yes, you should be fine...

[Bill D 2,047]

It should be able to spin a 60" deck if the grass isn't too tall.  Bill

Edited April 21, 2021 by Bill D

[Skipper 1,789]

That all depends what you expect from it. I know a local dude here who has a 60" on a 312, and it can mow grass.....at slow speed. The 16hp will also run the deck, but don't expect much more than a slow to medium pace. If grass is moist, thick, high, or you try to go just semi fast, 16hp will just not be satisfactory. A hydro machine would be preferable, to adjust speed on the fly to utilize the limited power best, or you will find yourself limited to a very slow gear most of the time.

Edited April 21, 2021 by Skipper