What’s happening?!

[WheelHorse520H 708]

Okay, I am stumped. I recently tore down and cleaned the Onan P220 on my 1988 520H because it was surging at operate. Long story short now it won’t run. I have the thread from the teardown Here. I cranked it and it would start so I adjusted the carb, back to what the service manual that was sent to me says. It puffed a couple times so I adjusted it and got it to run good and strong, but whenever there is a load on the engine i.e. moving forward or back or engaging the PTO with a 48” SD deck on. So I adjusted it more and it would not start. I got it to run again (with more adjusting) but same issue. I put in new spark plugs, no change. I put a jumper to the ignition coil and it seemed to run smoother, moved the jumper to the PTO switch to see if the issue was in there and it ran like it did without the jumper. I noticed the infamous 9-pin connector looked burned on the outside. But no, all the connections on the inside were normal and not corroded. Added some vaseline to act as dielectric grease. Nope that’s not it. I noticed it smelled like gas and saw some shooting out the exhaust, so I made the mixture leaner and it back fired, but now that’s as close as I can get to it running. PLEASE HELP.

Thanks,

Andrew

[lynnmor 7,308]

4 hours ago, WheelHorse520H said:

Okay, I am stumped. I recently tore down and cleaned the Onan P220 on my 1988 520H because it was surging at operate. Long story short now it won’t run. I have the thread from the teardown Here. I cranked it and it would start so I adjusted the carb, back to what the service manual that was sent to me says. It puffed a couple times so I adjusted it and got it to run good and strong, but whenever there is a load on the engine i.e. moving forward or back or engaging the PTO with a 48” SD deck on. So I adjusted it more and it would not start. I got it to run again (with more adjusting) but same issue. I put in new spark plugs, no change. I put a jumper to the ignition coil and it seemed to run smoother, moved the jumper to the PTO switch to see if the issue was in there and it ran like it did without the jumper. I noticed the infamous 9-pin connector looked burned on the outside. But no, all the connections on the inside were normal and not corroded. Added some vaseline to act as dielectric grease. Nope that’s not it. I noticed it smelled like gas and saw some shooting out the exhaust, so I made the mixture leaner and it back fired, but now that’s as close as I can get to it running. PLEASE HELP.

Thanks,

Andrew

We've been around this tree a number of times.  Gasoline coming out the muffler says it is flooded, fix the carburetor or learn how to use the choke.  You need three things for an engine to run, fuel in the correct amount, spark at the right time and correct compression.  Get the carburetor right, check the timing and you already checked the compression.  The procedures are right there in the Onan Service Manual.

 

There is no exterior adjustment that will change things enough to prevent gasoline from coming out of the exhaust.

 

You can jump around burned connections in the 9 pin, but you already jumped the entire system with the battery to coil jumper.  You cannot tell by looking if the 9 pin is good, it is best to replace the parts.

[WheelHorse520H 708]

19 hours ago, lynnmor said:

We've been around this tree a number of times.  Gasoline coming out the muffler says it is flooded, fix the carburetor or learn how to use the choke.

Sorry for not being clear, that was just stuff that had previously happened just to emphasize my confusion on this subject.

 

19 hours ago, lynnmor said:

Get the carburetor right,

I reset it to what the manual that you sent me says, and that’s when it blows the fuel out, I turn the idle mixture screw out to stop that and pull the spark plugs and blow off the excess gas and try again, the most I get from it is it running for a few seconds and dying and then not restarting.

 

19 hours ago, lynnmor said:

check the timing

Ignition, valves, or both?

 

19 hours ago, lynnmor said:

You cannot tell by looking if the 9 pin is good, it is best to replace the parts.

That was something I noticed but when I jump it, it runs the same… if it runs.

 

19 hours ago, lynnmor said:

There is no exterior adjustment that will change things enough to prevent gasoline from coming out of the exhaust.

Would this be a float adjustment then? That’s the only internal adjustment I know of.

 

Thanks,

Andrew

[lynnmor 7,308]

Could be float adjustment or a bad float.  Also it could be a bad float needle or seat.  Some folks turn the idle mixture screw in with force, destroying the needle and/or carburetor casting.  You should just turn it in gently till you feel the resistance.

 

Check the ignition timing per the manual, it isn’t adjustable but the flywheel key may be bad or installed wrong, throwing off the timing.

[WheelHorse520H 708]

On 8/31/2021 at 5:41 PM, lynnmor said:

float adjustment

I looked in the manual and saw there was a picture of the carb on its side, with fuel, and without. Only the one on its side said it was a float level adjustment, does this mean I need to remove the intake?

This was on page 7-3 of the manual.

Edited September 4, 2021 by WheelHorse520H

[WheelHorse520H 708]

Never mind, I just saw on the page before there is a section labeled “Removal” and the section I am using is labeled “Reassembly and Installation”. So it does need to come off.

[Tuneup 1,433]

I really despise that carb. My 16 gave me fits. Everything has to be just right. Why not turn off the fuel at the tank and get it started? If it clears up, it's either bad float, float adjustment or you installed an electric pump that is too high in pressure.

[lynnmor 7,308]

2 hours ago, WheelHorse520H said:

I looked in the manual and saw there was a picture of the carb on its side, with fuel, and without. Only the one on its side said it was a float level adjustment, does this mean I need to remove the intake?

This was on page 7-3 of the manual.

 

There is a drawing there that shows the fuel level in the upright position.  If you were to hold the float pivot pin in position and slowly fill the float bowl, the needle valve will seat when the fuel reaches the correct level.  This would best be done by filling thru the supply line with a tiny funnel or ketchup bottle.

 

 

[WheelHorse520H 708]

Sorry just saw this, I had it back together already. I had the floats totally messed up. It started and died, so better than last week. I went back to electrical gremlins and found the contacts on the key switch were corroded again. Cleaned ‘em off and it fired right up, ran for a solid 10-12 minutes I went to move the throttle and put my foot on the foot board to get on, and it stuttered so I shut it off and it backfired. Then It wouldn’t start. I think it might be a governor adjustment but I don’t know as much as you guys on here.

[lynnmor 7,308]

4 hours ago, WheelHorse520H said:

Sorry just saw this, I had it back together already. I had the floats totally messed up. It started and died, so better than last week. I went back to electrical gremlins and found the contacts on the key switch were corroded again. Cleaned ‘em off and it fired right up, ran for a solid 10-12 minutes I went to move the throttle and put my foot on the foot board to get on, and it stuttered so I shut it off and it backfired. Then It wouldn’t start. I think it might be a governor adjustment but I don’t know as much as you guys on here.

Try bypassing everything again.  I think you tried it before, just run a jumper wire from the battery + to the coil+.  I doubt you are after a governor problem.

[WheelHorse520H 708]

1 hour ago, lynnmor said:

Try bypassing everything again.  I think you tried it before, just run a jumper wire from the battery + to the coil+.  I doubt you are after a governor problem.

Ok, I would not be surprised if another connection was corroded. They seem to corrode quickly with our humid summers.

[WheelHorse520H 708]

I am not sure what happened, I started it this morning and it ran for a few seconds and died. It did the same thing a couple of times and now doesn’t start. I checked the connections at the seat switch, key switch, and the PTO switch. I used a test light and have power to the ignition coil, what else is there for me to check?

 

Thanks,

Andrew

[kpinnc 12,091]

10 hours ago, WheelHorse520H said:

I checked the connections at the seat switch, key switch, and the PTO switch. I used a test light and have power to the ignition coil, what else is there for me to check?

 

Are you sure the coil is good? I had one that was flaky, and it would run sometimes and not even fire other times. When the engine warmed up, it was dead completely.

[WheelHorse520H 708]

44 minutes ago, kpinnc said:

 

Are you sure the coil is good? I had one that was flaky, and it would run sometimes and not even fire other times. When the engine warmed up, it was dead completely.

Almost certain, I have two coils that both had correct resistance about a month ago. That’s why I’m stumped.

[Handy Don 12,237]

On 9/4/2021 at 9:09 PM, WheelHorse520H said:

Ok, I would not be surprised if another connection was corroded. They seem to corrode quickly with our humid summers.

Remedy for this is to coat the connections with dielectric grease. Not gobs of grease, just a coating.

 

18 hours ago, WheelHorse520H said:

I am not sure what happened, I started it this morning and it ran for a few seconds and died. It did the same thing a couple of times and now doesn’t start. I checked the connections at the seat switch, key switch, and the PTO switch. I used a test light and have power to the ignition coil, what else is there for me to check?

 

Thanks,

Andrew

 

6 hours ago, WheelHorse520H said:

 have two coils that both had correct resistance about a month ago. That’s why I’m stumped.

If this is happening with the jumper to the coil, then there are only two possibilities left. Not getting fuel (again, dirt or sticking float in the carb--likely) or the ignition module is failing (less likely). What you are seeing is nothing like the way the governor acts when it fails.

 

Check ignition module

Edited September 7, 2021 by Handy Don

[pacer 3,173]

I'm not familiar with the 220 but i have the B43 16hp and that thing is sooooo finiky/picky. Does the 220 have electronic ign? I,m assuming it does, ... but I'l relate a couple instances where mine was so weird.

 

When I got the B43 it would run/not run/run erratic. I have a series of steps I go through on a new - to me - buy, I go through the fuel sys, clean tank, new hose, etc, then I pull the carb and clean/inspect it, then I go to ign and ck coil/plugs/points/condenser (more on this later) Ended up with kit in carb, replace plugs, points/cond good. Symptons kept pointing to carb, run good one minute and next .... After HOURS of frustration I decided to - one more time - to go through my initial ck list. Last item was to - one more time - ck the points/cond, pull cover and still looks good ---- but wait!! what is the tiny hair line crack in the condenser wire?? So I pull the cond - again - and on close exam find that hairline crack was a crack in the wire covering right at where it came out of the cond and was brown colored (indicating heat) On flexing the wire it quickly opened up to a definite BIG crack!! EUREKA!! all the magic juice was leaking out that crack and jumping right to one of the socket head screws mounting the cover (that where the heat came from too!) Quickly found another condenser and mounted it on the coil ..... Ran like crazy, smooth as silk. crank right up, etc, etc All that time - and a lot of it! - it was the lowly little condenser

 

I have had several other adventures with the carb that I wont go into, except to say that it is finiky. On the B43 I found an electric fuel pump just would NOT work, would bypass the needle/seat with the 3 different ones I tried, so it is presently using the vacuum pump and - for the moment - its running beautifully!

 

But at the end of the day ----- by golly, I really DO like that Onan (when its running right!)

[WheelHorse520H 708]

5 hours ago, Handy Don said:

Remedy for this is to coat the connections with dielectric grease. Not gobs of grease, just a coating.

I used Vaseline on the key switch and PTO after I cleaned them.

 

4 hours ago, pacer said:

Does the 220 have electronic ign?

Yes it has electronic ignition.

 

4 hours ago, pacer said:

 

But at the end of the day ----- by golly, I really DO like that Onan (when its running right!)

Me too, I will never let mine go, it’s too good to get rid of. Thanks for the tips I’ll check some of that stuff out, the fuel line is about 2 years old.

[Handy Don 12,237]

1 hour ago, WheelHorse520H said:

I used Vaseline on the key switch and PTO after I cleaned them.

 

Yes it has electronic ignition.

 

Me too, I will never let mine go, it’s too good to get rid of. Thanks for the tips I’ll check some of that stuff out, the fuel line is about 2 years old.

Not sure who suggested Vaseline but I'm sorry to tell you it was a bum steer. It will conduct electricity but not resist heat and corrosion as well as dielectric!

You need dielectric grease. Period.  You'll have to clean off the Vaseline (use mineral spirits and let dry) and then apply the grease.

 

A quick check to separate fuel from ignition is to look for a spark. If you have a spark detector, use that. If not engage the parking brake, then remove a plug, make sure its shell is well grounded, and crank the engine. BE CAREFUL, the engine may start on the other cylinder! If you have spark, its most likely a fuel problem.

Edited September 7, 2021 by Handy Don

[WheelHorse520H 708]

23 minutes ago, Handy Don said:

Not sure who suggested Vaseline but I'm sorry to tell you it was a bum steer.

I’ve used it before and had no problems, and a quick google search of the questions show otherwise.

 

25 minutes ago, Handy Don said:

If you have a spark detector, use that.

Is this the same as a spark tester? Because my $10 autozone spark tester did not show any spark.

[Handy Don 12,237]

21 minutes ago, WheelHorse520H said:

I’ve used it before and had no problems, and a quick google search of the questions show otherwise.

 

Far be it from me to contradict a google search. If it works for you, ok.

I would suggest you read this (from a google search).

 

21 minutes ago, WheelHorse520H said:

Is this the same as a spark tester? Because my $10 autozone spark tester did not show any spark.

Yep. So fuel is off the table for the moment. Why no spark? Tested with the coil jumper solidly in place with assured good electrical contact? 

Time to go to the service manual and follow the ignition testing steps by looking for the pulses from the ignition module with a VOM. Do you have the manual and a VOM?

 

Edited September 7, 2021 by Handy Don

[WheelHorse520H 708]

2 hours ago, Handy Don said:

Tested with the coil jumper solidly in place with assured good electrical contact? 

No, I am going to start there again from square 1. 

 

2 hours ago, Handy Don said:

Do you have the manual and a VOM?

Yes, and yes. My digital multimeter is not the most expensive one, but I get a reasonable idea from it, better than without it at least.

[WheelHorse520H 708]

RedSquare! It’s been a couple days, been trying to get a carb issue on the bug squared away. I did some more testing this evening, and found two things, one it is very easy to loose on if the battery nuts, and two with the jumper back to the ignition coil it did not start. As I disconnected the negative battery terminal it gave a small puff which, quite honestly, scared the living daylights out of me.

[Handy Don 12,237]

On 9/10/2021 at 6:41 PM, WheelHorse520H said:

As I disconnected the negative battery terminal it gave a small puff

Please clarify. This does not sound like a good thing! What was the reason for disconnecting the battery?

 

You didn't say if you tested for spark

[WheelHorse520H 708]

2 minutes ago, Handy Don said:

Please clarify. This does not sound like a good thing! What was the reason for disconnecting the battery?

I did not want to leave the jumper on because I had to leave. I did forget to test for spark.

[WheelHorse520H 708]

I think I found the problem, when I cleaned the carb this fell off the needle valve and I didn’t notice. Gonna order a new needle valve soon. This little piece looks wicked uneven all the way around which is strange. Sorry, the photo is blurry but holding it there is a bunch of little tears all the way around.

Edited September 19, 2021 by WheelHorse520H