P220g on 520H Smoking

[TC10284 111]

First mow of the season yesterday! It was a struggle. Shredded a belt on a 518H when almost done with the front yard. Water in gas on a 312-8.

Then this (again)...

 

520H model 735501 S/N 6900662 with P220G. 

I got this one a while ago. When I got it, I adjusted the valves, oil change, intake/exhaust gaskets, etc, and did as much as I could as fair as maintenance on it.

 

Since I have been using it, I've noticed it smokes a good bit. White/blue tint smoke.

On startup, throttle up, and WOT, and when going up/down inclines/declines. I'll try to get a video later today. 

 

The problem(s) I have with it is that when using it for about 45min to an hour, it will just shut off. Sometimes it will sputter and die. Yesterday I mowed with it on a fairly mild day here in NC (65F was the high). I used it for about an hour and it just shut off when I was making a turn around for another stripe. It has a 42" rear discharge deck on it, so I'm not working it THAT hard.

It has to all be tied to burning oil. 

 

Last summer I had similar issues, but it would sputter and die and also just shut off. I also found it would foul out the rear spark plug which would eventually cause it to sputter and idle even worse. I haven't checked this season, but last season I did notice oil on the rear plug.

My thinking is that the flat out shut offs are either low oil sensor or temp sensor maybe? However, the dash light for engine temp doesn't flash. I saw the oil pressure light flash when it flat out died on me - during the dying process. 

The sputtering and dying may be the rear plug finally fouling out from too much oil in the gas/air mix. I could replace the plug and it would fire up and run great again (for a while). 

 

I am using some 10W30 oil and I've read that may be a bit too thin, yet I wouldn't think so. I've also tried some Lucas Stop Oil Leak. I can try straight 30W again?

 I checked the breather filter for the case before, last year, but I haven't this year. And it was clean and not blocked from what I remember. But I'd like to verify that when I can. 

 

So could this be valve seals, valve oil drain that is plugged, piston rings? Something else? Should I just repower this thing? I hate to spend $1600+ on a Vanguard or Honda kit. I'd be interested in a Predator repower, but I'm not an experienced small engine guy that has a lot of equipment for modifications, like needing to drill large holes in mounts, cut sheet metal, and so on (and meaning, getting down into the engine internals of the old P220 makes me nervous still). 

 

Thanks!

Edited March 15, 2020 by TC10284

[lynnmor 7,629]

You have no low oil sensor and the temperature sensor will not stop the engine,  The oil light will illuminate when an engine stalls due to no oil pressure.

 

You need to do a compression test first thing.  My guess is that you need a complete rebuild or replacement,  30 weight oil would be better, but that is not going to help much.

[TC10284 111]

34 minutes ago, lynnmor said:

You have no low oil sensor and the temperature sensor will not stop the engine,  The oil light will illuminate when an engine stalls due to no oil pressure.

 

You need to do a compression test first thing.  My guess is that you need a complete rebuild or replacement,  30 weight oil would be better, but that is not going to help much.

Last time I ran a compression check on this one I was getting around 115 to 120 for both cyl if I recall. I'll try to do that today and report back. 

[WVHillbilly520H 10,376]

I have ran 10w30 since new in my 520H in temps 80+ with no adverse issues... For a cheap thing to try with the plug fouling https://www.autozone.com/ignition-tune-up-and-routine-maintenance/spark-plug-non-fouler/dorman-help-18mm-gasket-seat-spark-plug-non-foulers-2-pack-42009/730544_0_0 before a complete tear down and rebuild... And the run 45-60 min shut down sounds to me more like the ignition module behind the flywheel going bad had one myself go out just like you describe 45 mins or so sputter sometimes back fire then die if it's not getting the signal/power to fire then the plug could foul as well just some experiences and thoughts on your situation.

Edited March 15, 2020 by WVHillbilly520H

[lynnmor 7,629]

1 hour ago, WVHillbilly520H said:

I have ran 10w30 since new in my 520H in temps 80+ with no adverse issues... For a cheap thing to try with the plug fouling https://www.autozone.com/ignition-tune-up-and-routine-maintenance/spark-plug-non-fouler/dorman-help-18mm-gasket-seat-spark-plug-non-foulers-2-pack-42009/730544_0_0 before a complete tear down and rebuild... And the run 45-60 min shut down sounds to me more like the ignition module behind the flywheel going bad had one myself go out just like you describe 45 mins or so sputter sometimes back fire then die if it's not getting the signal/power to fire then the plug could foul as well just some experiences and thoughts on your situation.

 

I agree that the ignition module might be the issue, but the smoking and oil fouling says to me that there is serious engine wear or damage.

[pfrederi 18,397]

Old school temporary solution straight 30w and add a pint of motor honey...or STP...if they still make them.  Then sell it quick

[cafoose 3,398]

I had problems like that with mine here is what I did:

 

 

[WVHillbilly520H 10,376]

1 hour ago, lynnmor said:

 

I agree that the ignition module might be the issue, but the smoking and oil fouling says to me that there is serious engine wear or damage.

I would like to know if there is an actual oil usage issue (adding oil after run) from the "smoking" or just plug fouling because of low spark energy as the non-foulers require "hot" spark to ignite, it is a cheap diagnostic tool IMO, it could be as simple as a stuck piston ring Marvel Mystery Oil added to the crankcase oil and fuel can help free up sticking valves and rings.

Edited March 15, 2020 by WVHillbilly520H

[tom2p 2,394]

as others have stated above - the type of oil and oil consumption is not the problem 

 

the oil consumption not a good sign and might be a symptom of the problem 

 

how much oil does it consume per hour of running ? 
 

our old 704 used oil - we ran it for  years and years like this - and probably could continue for more years ... of course the 704 is powered by a cast iron single cylinder Kohler - less finicky compared to an Onan twin 

 

 

[tom2p 2,394]

1 hour ago, WVHillbilly520H said:

I would like to know if there is an actual oil usage issue (adding oil after run) from the "smoking" or just plug fouling because of low spark energy as the non-foulers require "hot" spark to ignite, it is a cheap diagnostic tool IMO, it could be as simple as a stuck piston ring Marvel Mystery Oil added to the crankcase oil and fuel can help free up sticking valves and rings.

you might be on to something - maybe spark not sufficient to one of both cylinders 

 

if so - plug would probably be wet then - as much or more than oil fouled ?

 

 

[WVHillbilly520H 10,376]

15 minutes ago, tom2p said:

you might be on to something - maybe spark not sufficient to one of both cylinders 

 

if so - plug would probably be wet then - as much or more than oil fouled ?

 

 

Yes when the ignition module is weak (going bad) the spark is insufficient (BTW the Onan fires both cylinders at the same time regardless of cycle per cylinder) ... We had/have a K181 that even the non-fouler on the spark plug wasn't enough to keep the plug clean more than 3-4 hours run time and a pint of oil usage as well and smoked from start up idling and WOT most likely a broken ring or severely worn bore (haven't opened it up yet) but had a very blue spark when dry firing outside of the cylinder. IDK just throwing out some experiences I have had.

[peter lena 9,114]

tc284  , you could try this , its chemical make up , is very tacky , and has to be run in the engine till hot for best results. https://www.walmart.com/ip/Rislone-Ring-Seal-Smoke-Repair/22269732?wmlspartner=wlpa&selectedSellerId=10&adid=22222222227016838564&wl0=&wl1=g&wl2=c&wl3=52919137511&wl4=aud-430887228898:pla-84839958431&wl5=9003310&wl6=&wl7=9003291&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=22269732&veh=sem&gclid=Cj0KCQjwpLfzBRCRARIsAHuj6qVVKPa3PlrZv1v0S5z8qX5acxGU2gHDwiGkbTMZUyik70Mh3wIssxYaAjstEALw_wcB.  worth a  try , and it works. had an issue with a long lasting milky oil residue that was causing smoky starts , inside of a half hour of running , the oil mixture was total , no smoke. i would also insure a hot engine at oil change time , adding a little more to fresh oil . worth a try , pete

[TC10284 111]

I appreciate all the input here from everyone! 

Now that it is mentioned, I do agree that this sounds like it could be an ignition module. Thanks for pointing that out! I'll get a replacement and try it out. It makes sense because when it just died on me with no sputtering, the exhaust turned black as it was dying like the plugs received no spark at all instead of just one plug. 

 

As for the oil leak, I'll try the STP. I actually just bought some the other night. I'll also try the seal smoke repair and the plug foul part. 

 

For a stuck ring or valve, should I drain oil completely and try MMO separately to see if that helps, and then drain that and try STP/seal smoke repair? 

 

Thanks again! 

Edited March 16, 2020 by TC10284

[WHX?? 50,920]

Let us know how it shakes out for you TC.. I have one that was doing the same thing. Had a awful smell to the exhaust and front plug fouled. I pulled the motor and parting the 520 out as had some tranny axle and other issues. Seemed a shame as the rest of the tractor was in decent shape. I have the motor yet and plan is to eventually pull it apart just to see what is going on and see if it can be saved. I'm thinking it was caused by ring/bore issues as it used lots of oil?? 

[WVHillbilly520H 10,376]

1 hour ago, TC10284 said:

I appreciate all the input here from everyone! 

Now that it is mentioned, I do agree that this sounds like it could be an ignition module. Thanks for pointing that out! I'll get a replacement and try it out. It makes sense because when it just died on me with no sputtering, the exhaust turned black as it was dying like the plugs received no spark at all instead of just one plug. 

 

As for the oil leak, I'll try the STP. I actually just bought some the other night. I'll also try the seal smoke repair and the plug foul part. 

 

For a stuck ring or valve, should I drain oil completely and try MMO separately to see if that helps, and then drain that and try STP/seal smoke repair? 

 

Thanks again! 

Just add the MMO to the existing oil and fuel.

[TC10284 111]

3 hours ago, WVHillbilly520H said:

Just add the MMO to the existing oil and fuel.

Reason I asked is because I have some of the sticky STP in the blue bottle in there already that I had in my shop. 

Didn't want to counteract anything with MMO. 

[TC10284 111]

4 hours ago, WHX24 said:

Let us know how it shakes out for you TC.. I have one that was doing the same thing. Had a awful smell to the exhaust and front plug fouled. I pulled the motor and parting the 520 out as had some tranny axle and other issues. Seemed a shame as the rest of the tractor was in decent shape. I have the motor yet and plan is to eventually pull it apart just to see what is going on and see if it can be saved. I'm thinking it was caused by ring/bore issues as it used lots of oil?? 

 

I will! 

If i can keep her running more than 45min and without fouling plugs, even with some oil burn, I'll keep oil in her and try to be gentle with her. 

[WVHillbilly520H 10,376]

3 hours ago, TC10284 said:

Reason I asked is because I have some of the sticky STP in the blue bottle in there already that I had in my shop. 

Didn't want to counteract anything with MMO. 

MMO with the oil but not with the STP.

[TC10284 111]

An update to this:

I installed a new ignition module. Seems to run better, although it was a bit "poppy" when I first started it up and got to slightly over half throttle. It actually back fired twice before I throttled down. This was with the air filter/cover off while I was testing it. After it ran a bit, it seemed to be better and not do that. I could get to WOT without it popping. It didn't do that before. 

 

I have NOT ran it for >30min yet though. That would be the real test. I'll try to do that soon. 

[TC10284 111]

Just an update on this. I tried to use this one a few days ago to mow. It ran fine for about 10min. Then just sputtered out and died. Cranked up again and it ran for a couple minutes and died. Seemed like it had water in the gas, so yesterday I drained gas out of the tank. It had a lot of trash in the tank, but no water (drained into a clear container), so I cleaned that out and put in fresh. It ran rough for a few minutes, a lot of choke. Ran on one cylinder for a while. After it ran for a few minutes, the rear cylinder finally kicked in and started working and backfired a few seconds after that. Or maybe it had weak spark? But then shortly after it sputtered and died. 

Changed plugs assuming it had fouled another rear plug. Ran OK for a few minutes, just enough to unload some limbs from a trailer and sputtered/died half way back to the shed. Could only get her to fire for a few seconds and die. 

 

So I have already replaced the ignition module, and the rotor. So now I guess I am targeting the ignition coil and condenser. These have actually already been replaced a year or so ago. Otherwise, I am at a loss, unless the ignition module I got has issues itself. Research I've done seems to point to the ignition coil/condenser. I could take off the carb and clean it again, but there is a filter before fuel hits the carb...

Edited May 17, 2020 by TC10284

[Bill D 2,130]

Is the condenser on the positive terminal of the coil?  Onans have the condenser connected to the positive side not the negative like Kohlers with points.  Run a jumper from the positive on the coil to the battery positive.  If it runs fine then you may have a burnt 9 pin connector or fuse block terminal

If the there is a burnt terminal it could be causing a loss of power to the coil when it gets hot.

[lynnmor 7,629]

I didn’t see where you did a complete carb cleaning, make sure that is done.

[TC10284 111]

3 hours ago, Bill D said:

Is the condenser on the positive terminal of the coil?  Onans have the condenser connected to the positive side not the negative like Kohlers with points.  Run a jumper from the positive on the coil to the battery positive.  If it runs fine then you may have a burnt 9 pin connector or fuse block terminal

If the there is a burnt terminal it could be causing a loss of power to the coil when it gets hot.

 

The condenser is on the positive terminal of the coil. 

 

I'll try the jumper wire method soon. 

 

I'll also try cleaning the carb once again.

Edited May 18, 2020 by TC10284

[TC10284 111]

Another update:

Today I put in a new coil and condenser, and a clean spare carb. The previous one looked like it had a bit of water in it but not too bad. 

 

Put all back together. Starting running pretty good while it sat. So I cut it off to put the air cleaner and exhaust bracket back on. 

Started it back up. Ran rough like it was running on one cylinder. Finally the rear spark plug kicked in I guess(?). Did some test mowing with it. Stuttered a bit engaging the PTO. Ran alright but would intermittently sputter a tad and pick back up. It didn't cut off with me, but it seemed to get worse the more I test mowed. 

 

I'm of the opinion this thing needs a repower and motor rebuilt. The only thing I can figure on this thing is that it is getting too much oil in the rear cylinder fouling or almost fouling the plug, and the oil is messing up the stoichiometry of the fuel. And it smokes blue smoke quite a bit. Add to that, I can let it sit a few minutes to cool of, put new plugs in it and it works alright for a bit. 

 

I have not tried to jumper wire method yet though. 

 

This thing has had:
New rotor

New ignition module

Clean carb

New coil

New condenser

Countless new plugs

 

Edited May 23, 2020 by TC10284

[lynnmor 7,629]

I don't see where you checked the compression.