520 repower opinions

[gcole 36]

Hey guys, long time member but haven’t posted in quite some time. Long story short I picked up a non running 520. I’m wanting to repower this machine with a engine that parts are more readily available than the onan that’s currently under the hood. Does anyone have any suggestion? Kohler command? Honda twin? Briggs vanguard? A v twin diesel of some kind? Whatever I put in it needs to power a 60” mower for lots of grass cutting in the summer. Thanks for any insight and suggestions guys 

[WVHillbilly520H 10,376]

22hp Predator (Honda clone) from Harbor Freight, been several times, best to find an electric PTO clutch though.

[horseyheaven 113]

Small engine warehouse makes a kit to install a 23hp Briggs Vanguard.  This kit costs $1650.  I considered this until I began tearing into my Onan to see what it needed.  I was lucky and only needed rings, gaskets, valve seals, and oil pump.  I was able to rebuild it and bring it back to specs for about $250.  I am glad I did because it runs just as strong as when it was new for a lot less money than a reporter.  One thing to check is the valve seats.  If they are good and the crank, rods, and pistons are good it should not cost very much to redo it.  While it was apart, I used a hole saw to put 12 one inch holes in the belt guard for increased air flow and cooling to the back cylinder.  I also found a remote oil filter kit and moved the oil filter out of the way on the back cylinder to allow for more air flow as well.  If you decide to rebuild the Onan and want to check out the prices of parts, Onanparts.com is the best and they will fix you right up with what you need.  You can go to their website and  search parts and prices.  Good luck on your decision.  If you have any other questions, ask away.

[pacer 3,177]

You said 'non running' -- is that because of the Onan? Or?

 

Reason I ask is my thinking is along the lines in the above post, While the Onan has some weak points, when they are in good running condition, they are a beast! I would certainly at least inspect the Onan with an eye for a possible rebuild ... If you should find it in comparable condition to what horsey sez --- then thats the way I'd go too.

[littleredrider 409]

I don't have a deck hooked to mine, but one of my 520s has a 10 horse diesel. I had this motor years ago, ran a 48" deck, had a problem of the clutch slipping, but never a lack of power. I always said if the Onan goes in the other 520 that I'd put in the HF motor in it....

[gcole 36]

The onan engine does run, it revs to the moon as soon as it fires up. I’m all but sure it’s the flyball spacer for the governor balls slipping. Problem is, I’ve had zero luck locating one to replace and locktite on. The one in it is the plastic one and I’d like to update to the metal one. This is the second onan I’ve owned that has this problem. I’m up in Canada also so a lot of the engines you guys have access to are much more expensive and harder to get ahold of up here  

[gcole 36]

I also don’t think the 10 horse diesel would quite have enough power for the 60”. That’s a lot of deck for 10 horse. I do have access to a 20 horse kohler command that needs some love but the specs put it at a bit shy in torque compared to the onan. I agree the onans when running are a powerful engine. Parts have just become harder to obtain 

[WVHillbilly520H 10,376]

2 minutes ago, gcole said:

I also don’t think the 10 horse diesel would quite have enough power for the 60”. That’s a lot of deck for 10 horse. I do have access to a 20 horse kohler command that needs some love but the specs put it at a bit shy in torque compared to the onan. I agree the onans when running are a powerful engine. Parts have just become harder to obtain 

A v-twin of the same HP rating will never have the torque of an opposed twin, so what about a KT-17/18 Kohler or even a Briggs opposed twin from a WH or Sears donor? I love my ONANS but haven't had any major mechanical issues of yet in 22 years so I can't give you any specifics, I don't know if 1 could change out the cam/ flyball/governor from a B series to P series ONAN to gain the metal spacer over the nylon, there is another thread going on about custom machined parts and making new/replacement spacers for these engines, now with a diesel its not necessarily the HP rating its about the torque to run the decks and such.

[gcole 36]

13 minutes ago, WVHillbilly520H said:

A v-twin of the same HP rating will never have the torque of an opposed twin, so what about a KT-17/18 Kohler or even a Briggs opposed twin from a WH or Sears donor? I love my ONANS but haven't had any major mechanical issues of yet in 22 years so I can't give you any specifics, I don't know if 1 could change out the cam/ flyball/governor from a B series to P series ONAN to gain the metal spacer over the nylon, there is another thread going on about custom machined parts and making new/replacement spacers for these engines, now with a diesel its not necessarily the HP rating its about the torque to run the decks and such.

I understand the torque to horsepower comparison. Im a ag tech by trade. I just personally can’t see the 10 horse diesel having compatible torque to the 20 onan. Has anyone ever installed an air cooled vtwin diesel? I’m not against putting another opposed twin In the tractor. Again it’s finding one. I haven’t been able to run across one as of yet that strikes me as a good swap candidate 

Edited February 20, 2021 by gcole

[WVHillbilly520H 10,376]

Just now, gcole said:

I’m not against putting another opposed twin In the tractor. Again it’s finding one. I haven’t been able to run across one as of yet that strikes me as a good swap candidate 

I have heard very good things about the Predators, but you need to a bit of fabricating to get it to work as the PTO shaft is 1" vs WH spec 1 1/8" and then its not completely understood if their crankshafts can handle the side thrust load of the manual PTO clutch so electric may be needed for safer operation, and the muffler outlet points to the rear as made and may interfere with the hood closing, so in the end it may not be cost effective, ... Also here is a  shop offering core/swap rebuilding of ONAN...

http://shop.kustomlawnandgarden.com/ONAN-ENGINES-REMANUFACTURED_c5.htm

[gcole 36]

1 minute ago, WVHillbilly520H said:

I have heard very good things about the Predators, but you need to a bit of fabricating to get it to work as the PTO shaft is 1" vs WH spec 1 1/8" and then its not completely understood if their crankshafts can handle the side thrust load of the manual PTO clutch so electric may be needed for safer operation, and the muffler outlet points to the rear as made and may interfere with the hood closing, so in the end it may not be cost effective, ... Also here is a  shop offering core/swap rebuilding of ONAN...

http://shop.kustomlawnandgarden.com/ONAN-ENGINES-REMANUFACTURED_c5.htm

The fab work to make it happen ain’t a problem. I’ve been reading on them but getting a predator here in Canada has also not been lucky yet. I do work at a ag dealer that sells Honda so I can get some prices on a Honda at dealer price. From what I understand the predator is based off the Honda 

[horseyheaven 113]

You may try this guy.  I believe he has a fix for this.  Here is his email and phone number.

boomers_influence@yahoo.com  Or call 651 437 2826. He is on central time open M to F 10 to 7 and Sat 12 to 6.

You May also try Cummins diesel as they bought out Onan.  Also, Linamar Lx series engines are the same as the p series.  I thought the Linamars were made in Canada.  Some I have seen just say Linamar, others say Linamar Onan.  Hope this helps.  Let us know how it turns out.  I had a friend say he bought a fly ball spacer from the above guy and it took care of his problem.

[WVHillbilly520H 10,376]

1 minute ago, gcole said:

The fab work to make it happen ain’t a problem. I’ve been reading on them but getting a predator here in Canada has also not been lucky yet. I do work at a ag dealer that sells Honda so I can get some prices on a Honda at dealer price. From what I understand the predator is based off the Honda 

Yes Honda clone, and I believe a RS member here @Red-Bovine did the Honda swap on a 520, maybe they will chime in.

[Handy Don 14,061]

53 minutes ago, gcole said:

I understand the torque to horsepower comparison. Im a ag tech by trade. I just personally can’t see the 10 horse diesel having compatible torque to the 20 onan. Has anyone ever installed an air cooled vtwin diesel? I’m not against putting another opposed twin In the tractor. Again it’s finding one. I haven’t been able to run across one as of yet that strikes me as a good swap candidate 

I saw a P216 for sale recently -- condition unknown but allegedly running

 

[1995 520H+96+97 937]

Many spiders on E-bay.

[6wheeler 669]

42 minutes ago, horseyheaven said:

You may try this guy.  I believe he has a fix for this.  Here is his email and phone number.

boomers_influence@yahoo.com  Or call 651 437 2826. He is on central time open M to F 10 to 7 and Sat 12 to 6.

You May also try Cummins diesel as they bought out Onan.  Also, Linamar Lx series engines are the same as the p series.  I thought the Linamars were made in Canada.  Some I have seen just say Linamar, others say Linamar Onan.  Hope this helps.  Let us know how it turns out.  I had a friend say he bought a fly ball spacer from the above guy and it took care of his problem.

Boomer does have some NOS 18 hp short blocks. He can tell you how to make it work with parts off of your P220. The only problem as he told me was that the crank is a bit shorter on the clutch side. But? He has a plan for that as well.. Not cheap. The Honda engines do go on fairly easily. And? Being as that you work for a dealer? Should be relatively easy. I think it is the GS 650 that works.  Good luck

[littleredrider 409]

It might not have the horse, but can almost guarantee it has more torque. Its not an apples to apples comparison, but my 520-8 has the Onan, and the 520H has the diesel. I put a one bottom plow on each of them, and the diesel pulled the plow effortlessly. Think Im gonna be selling the 520H with the diesel, but i wouldn't hesitate to run the 60" deck with it. When I built the diesel, I had no intentions of putting on the PTO... 

[tom2p 2,394]

10 hours ago, gcole said:

The onan engine does run, it revs to the moon as soon as it fires up. I’m all but sure it’s the flyball spacer for the governor balls slipping. Problem is, I’ve had zero luck locating one to replace and locktite on. The one in it is the plastic one and I’d like to update to the metal one. This is the second onan I’ve owned that has this problem. I’m up in Canada also so a lot of the engines you guys have access to are much more expensive and harder to get ahold of up here  

appears you have the knowledge - are very mechanically inclined - and up to the task of repairing the Onan 

 

there gotta be spacers out there ... somewhere ... ? ... 

 

[Bill D 2,247]

13 hours ago, gcole said:

The onan engine does run, it revs to the moon as soon as it fires up. I’m all but sure it’s the flyball spacer for the governor balls slipping. Problem is, I’ve had zero luck locating one to replace and locktite on. The one in it is the plastic one and I’d like to update to the metal one. This is the second onan I’ve owned that has this problem. I’m up in Canada also so a lot of the engines you guys have access to are much more expensive and harder to get ahold of up here  

I believe one of our members is making them.  Check with  @bcgold

Edited February 21, 2021 by Bill D

[Skipper 1,789]

They now make 14, 16 and 18 horse single Diesels, up to 818cc. And 1267cc v-twins with 30 hp. I run a 25hp 997cc v-twin diesel, and it's a perfect match for the 60". No way can a 10 hp pull it, if you expect to mow at a decent pace. Just not happening.

 

If you want to go gas engine, I would look for a low hour kohler v-twin. Much more modern, rock solid, and it will outperform any of the old engines. Something like what you find in a 522Xi or newer. As said, remember to go electric clutch.

[Maxwell-8 4,367]

43 minutes ago, Skipper said:

And 1267cc v-twins with 30 hp. I run a 25hp 997cc v-twin diesel,

Where  do you find those engines? Which make are they?

 

Does it even fit?

Edited February 21, 2021 by Maxwell-8

[Skipper 1,789]

I import them from china to EU. Can also have then send world wide.

 

They are clones of Yanmar. The type they have made in china for many years now, and they are now a good engine IMO. My source is the factory that makes them for the local market and military use in gennys and pumps. The most reliable manufacturer of these engines.

 

If it fit, depends on what tractor you want to put it in. The twins fit under the hood of a C195 with minor adjustments, but of cause you will have to tinker a bit.

 

The singles come in different hights, depending on hp. They go from small nut burner engines about 4hp, and up to 18hp in roughly 2hp intervals.

 

They also come in a twin version for vertical shaft use.

 

You will need an electric clutch on the crank to be on the safe side.

[Maxwell-8 4,367]

23 minutes ago, Skipper said:

Yanmar

May have a real Yanmar L100 (10hp) lying around in the garage.... But i wouldn't think it could fit in my 312.

[gcole 36]

3 hours ago, Skipper said:

They now make 14, 16 and 18 horse single Diesels, up to 818cc. And 1267cc v-twins with 30 hp. I run a 25hp 997cc v-twin diesel, and it's a perfect match for the 60". No way can a 10 hp pull it, if you expect to mow at a decent pace. Just not happening.

 

If you want to go gas engine, I would look for a low hour kohler v-twin. Much more modern, rock solid, and it will outperform any of the old engines. Something like what you find in a 522Xi or newer. As said, remember to go electric clutch.

Do you happen to have a link for the Diesel engine you used? Do you think that it would fit under the hood of the 520? Making a new air box and exhaust is no issue. I’d definitely look into shipping it to Canada. Diesel would be really nice as on the farm I have a diesel tank to fill it haha. 

[gcole 36]

8 hours ago, tom2p said:

appears you have the knowledge - are very mechanically inclined - and up to the task of repairing the Onan 

 

there gotta be spacers out there ... somewhere ... ? ... 

 

I’ve been watching for one. The whole being in Canada thing makes everything a little more expensive to get ahold of. Basically I’m weighing out the options of repair or repower route. I really want a good dependable machine that if something happens I’m not down for weeks to get parts