Brockport Bill 1,926 #26 Posted July 4 One thing people don't typically check is the tranny plate under tractor that has 4 bolts that connects the frame to transmission...it can often have fracture cracks running from bolt holes...tractors that were used hard, notably tiller or plow use, grader blade, or heavy 60 inch mower could have been subject to stress on that plate. 1 Share this post Link to post Share on other sites
kpinnc 14,567 #27 Posted July 4 38 minutes ago, Brockport Bill said: One thing people don't typically check is the tranny plate under tractor that has 4 bolts that connects the frame to transmission...it can often have fracture cracks running from bolt holes...tractors that were used hard, notably tiller or plow use, grader blade, or heavy 60 inch mower could have been subject to stress on that plate. Not to mention on a manual tranny when the driver likes wheelies... 1 Share this post Link to post Share on other sites
TonyToro Jr. 1,917 #28 Posted July 4 6 hours ago, Sparky said: Your 9 pin connector looks like it’s toasted. That’ll need to be added to your list of things to address. Thanks Mike. From what I heard there no good. I looked inside and it looked ok but will probably be replace. Share this post Link to post Share on other sites
TonyToro Jr. 1,917 #29 Posted July 4 Looking at the pictures more. I’ve noticed some 520s have an oil filter. Where is it? Share this post Link to post Share on other sites
peter lena 9,231 #30 Posted July 4 @ tony toro jr , opportunity on the deck ? middle of lift frame to deck ? in addition to bearing lubrication change over , have added a flat idler pulley to back side of spindle belt , just pushing toward front of deck , drill a hole in deck for mounting , that long UNSUPPORTED BELT BOUNCE , goes away , also reduces , that additional vibration effect on related bearings . have that set up on 3 decks , no noise or bearing whine , realise the rest of deck is rough , maybe a clean out and lubrication / hot sun soaking ? you have a ton of things to do , but the deck is part of it , would also think about a relocation of that 9 pin , near some cooler air flow . wish you the best on recovery , pete 1 Share this post Link to post Share on other sites
lynnmor 7,787 #31 Posted July 4 29 minutes ago, TonyToro Jr. said: Looking at the pictures more. I’ve noticed some 520s have an oil filter. Where is it? On the left rear of the engine. Be sure to buy the proper filter that is long enough and fits the rubber gasket well. Most likely that gasket is missing or rotted. Share this post Link to post Share on other sites
Chaz54 79 #32 Posted July 4 10 hours ago, TonyToro Jr. said: How could you tell? Just with the model number or changes with the tractor? I could tell by the shift lever without even looking at the model number. 1 Share this post Link to post Share on other sites
TonyToro Jr. 1,917 #33 Posted July 4 11 minutes ago, lynnmor said: On the left rear of the engine. Be sure to buy the proper filter that is long enough and fits the rubber gasket well. Most likely that gasket is missing or rotted. Found it thanks! Share this post Link to post Share on other sites
lynnmor 7,787 #34 Posted July 4 (edited) 5 minutes ago, TonyToro Jr. said: Found it thanks! Told you the gasket would be missing, don't run without it because 30% of the cooling air is lost there. People complain about valve seat issues with this engine but continue to abuse them. I run only Onan 122-0800 or Fleetguard LF3339 oil filters. I see that the current filter is too short. Edited July 4 by lynnmor 1 1 Share this post Link to post Share on other sites
slim67 2,809 #35 Posted July 4 15 hours ago, squonk said: Check all of those bolts on the engine around the PTO bearing. When they loosen you lose all the oil real quick! That's why I got mine so cheap!! Bearing plate bolts were finger loose and oil from the feed port was shooting out. New gasket and seal plus degreaser and pressure wash. 1 Share this post Link to post Share on other sites
TonyToro Jr. 1,917 #36 Posted July 7 So did a little work on the 520-h the past few days. So we confirmed the owner wasn’t right and it has spark in both cylinders after all. Didnt look up what a good compression is on these but I got about 125 PSI in both cylinders. New ish battery and it cranks over and sounds good. All the gauges and warning lights seem to work too. 1 Share this post Link to post Share on other sites
Handy Don 13,966 #37 Posted July 7 5 minutes ago, TonyToro Jr. said: Didnt look up what a good compression is on these but I got about 125 PSI in both cylinders. This is excellent compression. 1 Share this post Link to post Share on other sites
Handy Don 13,966 #38 Posted July 7 (edited) I’m sure you’ve read threads about the Onans and how to avoid trouble. They MUST be looked after! Airflow is critical so a good clean out under the tins and among the fins, especially the rear cylinder, should be considered regular maintenance. If there isn’t already a foam rubber gasket in place around the oil filter sealing it to the tin, get one ASAP. If you must run it in the meantime, firmly tape over the hole -- I’ve seen estimates that 30% of the cooling air is lost without the gasket. Enjoy! Edited July 7 by Handy Don 1 Share this post Link to post Share on other sites
TonyToro Jr. 1,917 #39 Posted July 7 27 minutes ago, Handy Don said: I’m sure you’ve read threads about the Onans and how to avoid trouble. They MUST be looked after! Airflow is critical so a good clean out under the tins and among the fins, especially the rear cylinder, should be considered regular maintenance. If there isn’t already a foam rubber gasket in place around the oil filter sealing it to the tin, get one ASAP. If you must run it in the meantime, firmly tape over the hole -- I’ve seen estimates that 30% of the cooling air is lost without the gasket. Enjoy! Yup it’s missing the rubber gasket. I plan on pulling all the tins off the engine and tractor and giving it a good bath. Share this post Link to post Share on other sites
Handy Don 13,966 #40 Posted July 7 45 minutes ago, TonyToro Jr. said: Yup it’s missing the rubber gasket. I plan on pulling all the tins off the engine and tractor and giving it a good bath. I'll try to head off some frustration now... There is one bolt holding the top of the shroud UNDER the coil. Be careful not to drop it when removing it since it’ll want to go down under the intake manifold! There are two bolts holding the very bottom that you reach through holes in the engine mounting plate below the flywheel. 1 Share this post Link to post Share on other sites
kpinnc 14,567 #41 Posted July 8 (edited) Just a suggestion here as well: An Onan engine requires a bit more work to get the shroud off to inspect the cooling fins- as you already know. I think this is one of the main reasons these engines overheat and loose the valve seats: Very few people take the time to remove the shroud and regularly inspect the fins. Another is the Wheel Horse drive belt guard- but there are dozens of examples of how to get around that. What I did was to cheat a bit on fin inspection. I used a 1 inch hole saw and bought some snap in plugs the same diameter to make an inspection port. You can use your phone or if you really wanna go big get a borescope. Either way, this allows you to verify the fins are clear on that dreaded rear cylinder. You can also get a spray nozzle in there if they need cleaning. Never spray a hot engine though... A strong P220 is an awesome engine. Keep those fins clean, and the maintenance up and it will easily last 3000+ hours. Edited July 8 by kpinnc 1 Share this post Link to post Share on other sites
Handy Don 13,966 #42 Posted July 8 7 hours ago, kpinnc said: A strong P220 is an awesome engine. We run its smaller sibling, a P218, and I am constantly amazed at the torque. 1 Share this post Link to post Share on other sites
Bill D 2,246 #43 Posted July 8 I've got three P216's. Love the torque and sound when the governor kicks in. 1 Share this post Link to post Share on other sites