Onan P220 surging/hunting at operate

[Maxwell-8 4,275]

13 hours ago, WheelHorse520H said:

New update: the intake manifold does not leak, holds the water just fine. The gasket between the carb and the intake was crushed one heck of a lot, could air get in that way? I do need new head gaskets and new intake and exhaust gaskets, should I just get one for the seam on the intake manifold since I have it all apart?

When you may have a leak, i spray brake cleaner on every part of the inlet after the carb when she is running. Does the rpm change (raise), there is the leak!

[WheelHorse520H 708]

8 minutes ago, Maxwell-8 said:

When you may have a leak, i spray brake cleaner on every part of the inlet after the carb when she is running. Does the rpm change (raise), there is the leak!

I read that before, and was going to do that but........ I was driving it one day and I had just learned the voltage regulator was bad. It died, in the middle of the driveway, so while a waited for the voltage regulator I started on this. However it this little tear down I did does not do the trick, I will certainly try that.

[Maxwell-8 4,275]

3 minutes ago, WheelHorse520H said:

I was driving it one day and I had just learned the voltage regulator was bad. It died, in the middle of the driveway

Got lucky the voltage regulator died that way. I am gone pick up a tractor this week, with a battery that exploded because of a to high voltage! battery acid everywhere, gone be fun to clean up

[WheelHorse520H 708]

3 minutes ago, Maxwell-8 said:

Got lucky the voltage regulator died that way. I am gone pick up a tractor this week, with a battery that exploded because of a to high voltage! battery acid everywhere, gone be fun to clean up

That must have been scary for the previous owner. Yikes!  Have fun with that clean up.

[WheelHorse520H 708]

Update: Piston heads are nice and clean, @lynnmor I do not have a plastic scraper, and O’Reilly, Autozone, and Napa all did not have one so I used engine degreaser and so elbow grease. They look better, but are not perfect. Do you recommend a certain gasket set?

Andrew

[lynnmor 7,306]

39 minutes ago, WheelHorse520H said:

Update: Piston heads are nice and clean, @lynnmor I do not have a plastic scraper, and O’Reilly, Autozone, and Napa all did not have one so I used engine degreaser and so elbow grease. They look better, but are not perfect. Do you recommend a certain gasket set?

Andrew

Any scrap of plastic or an ice scraper will do.  Think outside the box.
Since I have had issues with the cheap gaskets, I use only genuine Onan gaskets.

[WheelHorse520H 708]

51 minutes ago, lynnmor said:

Any scrap of plastic or an ice scraper will do.  Think outside the box.
Since I have had issues with the cheap gaskets, I use only genuine Onan gaskets.

Ice scraper......that’s genius!

[kpinnc 12,054]

I would also use a shop vac to get out all the small debris that may slip in the gap between the top of the piston and cylinder wall above the rings. Do NOT use compressed air to clean it. 

[WheelHorse520H 708]

14 minutes ago, kpinnc said:

Do NOT use compressed air to clean it. 

So I don’t blast all the gunk into the crankcase.....not sure I want to know how you learned that.

 

15 minutes ago, kpinnc said:

 

I would also use a shop vac to get out all the small debris that may slip in the gap between the top of the piston and cylinder wall above the rings.

 

Someone on this thread suggested some grease to seal the gap, but using engine degreaser, kind of defeated the purpose.

[kpinnc 12,054]

13 minutes ago, WheelHorse520H said:

So I don’t blast all the gunk into the crankcase.....not sure I want to know how you learned that.

I'll never tell...

People say we learn from our mistakes, but if that were true I should be a genius...

 

Btw- while you have the engine opened up, it's a good time to adjust the valves too. One less thing to worry about. Most gasket kits come with those gaskets anyway.

Edited May 20, 2021 by kpinnc

[WheelHorse520H 708]

Sorry, I have been busy, I was looking at gasket sets and I found one here but I am not sure what the valve covers are since I just thought it was the cylinder head. I will order the glass beads too. While I wait I will start the carb cleaning that I keep forgetting. Btw I forgot to post a picture of the cleaned piston heads, should I worry about those small black patches? Thanks for all the help.

Andrew

[WheelHorse520H 708]

On 5/20/2021 at 3:31 PM, lynnmor said:

Since I have had issues with the cheap gaskets, I use only genuine Onan gaskets.

Are these kits Here and Here good? Also, is there a valve cover or is it just the cylinder head? Thanks for the help,

Andrew

P.S. Please see last post about piston heads.

[lynnmor 7,306]

1 hour ago, WheelHorse520H said:

Are these kits Here and Here good? Also, is there a valve cover or is it just the cylinder head? Thanks for the help,

Andrew

P.S. Please see last post about piston heads.

 

onanparts.com sells genuine Onan parts, so they are what you want.  You need to read up on the valve adjusting, apparently you don't know how that is done.  See page 10-2.

[WheelHorse520H 708]

2 hours ago, lynnmor said:

You need to read up on the valve adjusting, apparently you don't know how that is done.  See page 10-2.

I assume this will tell me where / what the valve cover is. Thanks again,

Andrew

[lynnmor 7,306]

Look at your post #36, just above the top head bolt hole you will see a 7/16" head of a bolt.  There is one on each side of the engine holding down the valve covers.  Work clean and don't drop debris in as you remove them.  There is holes to return the oil in the bottom of the uncovered area, stuff some paper towel in them to keep debris out.  A shop vacuum is a good way to clean as you go.

 

The Onan manual gives a method of getting the cam in the right location for adjustment.  I simply rotate the engine crankshaft till a valve is pushing the spring to the maximum, then turn the crankshaft one more turn.  A chalk mark on the rear pulley is good enough.  Do this with each of the four valves making sure that you know which are intake and exhaust.  If you find a valve that is way off, come back and maybe we can determine what is happening.

Edited June 8, 2021 by lynnmor

[kpinnc 12,054]

I'm thinking those black spots on top of the pistons are little dents from contacting carbon buildup at the top of the stroke. Probably nothing to be so much concerned about now- but also a reminder of the importance of the 500 hour head cleaning being necessary.

 

...Not preaching at all, more or less typing out loud. 

[WheelHorse520H 708]

5 hours ago, kpinnc said:

...Not preaching at all, more or less typing out loud. 

Preach away, I noticed yesterday the amount of carbon on the cylinder heads, more thank I like to have so that sounds like a project for tomorrow. That does make sense though. Also, I noticed a little oil dripping out of the back cylinder, I know that is usually not good. However, it is on a steep incline so would the oil be able to ooze over about a month of sitting on a steep incline. First pic is the front cyl second is the back.

[lynnmor 7,306]

If the engine is lower on the end that is dripping, a little oil can be expected.  It wouldn't be an Onan if it didn't puff a little white smoke on a cold start.

[WheelHorse520H 708]

48 minutes ago, lynnmor said:

If the engine is lower on the end that is dripping, a little oil can be expected.  It wouldn't be an Onan if it didn't puff a little white smoke on a cold start.

You have no idea the relief you just gave me. I agree on the white puff of smoke though!

[Handy Don 12,230]

This reminds me of a joke I heard during my younger years as a percussionist.

What does it mean when the drummer is drooling out of both sides of his mouth?

The stage is level.

badumbum. 

[WheelHorse520H 708]

I did some sand/glass blasting today, I used about 48 pounds of glass beads on just the shield that goes under the stainless steel grate and I am glad I set up a tarp to catch the extra beads because that created a mess where the tarp wasn’t able to reach. The black paint came right off but there is some large patches of rust that I just can’t seem to get off. Should I use a more coarse grit? I know I need to blast the muffler and the black head shield, is there anything else that I have to blast?

Thanks,

Andrew

[Jeff-C175 7,202]

On 6/11/2021 at 12:54 PM, Handy Don said:

This reminds me of a joke I heard during my younger years as a percussionist.

What does it mean when the drummer is drooling out of both sides of his mouth?

The stage is level.

badumbum. 

 

That probably started as a banjo picker joke.  Uh-oh, here I go off topic again:

 

Q: How do you get rid of the banjo picker knocking at your door?

 

A: Pay for the pizza and close the door.

 

[WheelHorse520H 708]

On 6/8/2021 at 2:56 PM, lynnmor said:

Look at your post #36, just above the top head bolt hole you will see a 7/16" head of a bolt.  There is one on each side of the engine holding down the valve covers.  Work clean and don't drop debris in as you remove them.  There is holes to return the oil in the bottom of the uncovered area, stuff some paper towel in them to keep debris out.  A shop vacuum is a good way to clean as you go.

This bolt you describe is it next to the crankcase breather tube?

[lynnmor 7,306]

11 minutes ago, WheelHorse520H said:

This bolt you describe is it next to the crankcase breather tube?

 

Of course.

[Handy Don 12,230]

Give the area around the covers a good clean and vacuum before removing the covers (stick paper towels or clean rags in the intake and exhaust ports on both cylinders if you haven't already!

Also, removing the breather tube by loosening the clamp will get it out of your way and lessen the chance of dropping debris in to the valve stem chamber.

Seriously important to keep debris out of the engine.

Edited June 18, 2021 by Handy Don