Onan P220 surging/hunting at operate

[Horse Newbie 7,069]

2 hours ago, WheelHorse520H said:

Okay, so I learned that onanparts.com is not taking orders until August 8th. Where have people had good luck finding the gaskets I need?

While there may be(not sure) other source's for Onan Parts, I have heard many on Red Square recommend using genuine Onan gaskets as others WILL fail...

[Handy Don 12,227]

33 minutes ago, Horse Newbie said:

While there may be(not sure) other source's for Onan Parts, I have heard many on Red Square recommend using genuine Onan gaskets as others WILL fail...

Colburn Power Systems is another possibility. I have not used them personally. Their main business is generators and welders that use Onan's.

 

Edited July 11, 2021 by Handy Don

[WheelHorse520H 708]

4 hours ago, Horse Newbie said:

While there may be(not sure) other source's for Onan Parts, I have heard many on Red Square recommend using genuine Onan gaskets as others WILL fail...

That was kind of my question, I have heard horror stories of failed gaskets.

 

3 hours ago, Handy Don said:

Colburn Power Systems is another possibility. I have not used them personally. Their main business is generators and welders that use Onan's.

 

I will check that out, thanks for the suggestion.

[lynnmor 7,306]

I have used Colburn when the other one is closed.  I found the prices to be good, you will need the correct Onan part number to enter in the search box.

[WheelHorse520H 708]

Colburn Power had most of the gaskets but they were more than twice the price so I will just wait a couple of weeks.

[lynnmor 7,306]

1 hour ago, WheelHorse520H said:

Colburn Power had most of the gaskets but they were more than twice the price so I will just wait a couple of weeks.

 

I used them over the winter and they were the cheapest on every item except one, and that was just pennies more.

[WheelHorse520H 708]

The two kits listed in post # 37 came to a total of about $55 but Colburn Power had only one of the kits and it was $101.87. Although I looked at some of their other stuff and the prices seemed reasonable.

[lynnmor 7,306]

7 hours ago, WheelHorse520H said:

The two kits listed in post # 37 came to a total of about $55 but Colburn Power had only one of the kits and it was $101.87. Although I looked at some of their other stuff and the prices seemed reasonable.

 

I think that you will find that the packaged Onan kit #168-0189 contains valve seals and a few more gaskets.  The kit sold by onanparts appears to be loose gaskets selected by the seller.  Try using just the part numbers of the individual gaskets and see how that compares.

[WheelHorse520H 708]

3 hours ago, lynnmor said:

 

I think that you will find that the packaged Onan kit #168-0189 contains valve seals and a few more gaskets.  The kit sold by onanparts appears to be loose gaskets selected by the seller.  Try using just the part numbers of the individual gaskets and see how that compares.

That would explain the drastic price difference, it’s too bad they give you no pictures ore details about the kit at colburn.

[lynnmor 7,306]

3 hours ago, WheelHorse520H said:

That would explain the drastic price difference, it’s too bad they give you no pictures ore details about the kit at colburn.

Colburn basically deals in parts for Onan generators but many parts are correct for our use.  That is why I suggested using the correct Onan part numbers.  Onanparts is more helpful, and in this one case he should not have used the kit number only a description of his kit, he did include the part numbers.  A true valve grind job should include valve seals.  You don't need the full kit, but if you do need other parts such as valves seals, you will need to add them.

[WheelHorse520H 708]

45 minutes ago, lynnmor said:

Colburn basically deals in parts for Onan generators but many parts are correct for our use.

I learned that yesterday when I was on their site all the parts for Kohler and Onan were labeled for generators. The Onan ones were for the Cummins Onan RV generators. And they also had advertised brands like Generac.

 

48 minutes ago, lynnmor said:

You don't need the full kit, but if you do need other parts such as valves seals, you will need to add them.

The valves all seal, and I need a carb to intake manifold gasket, do I need anything else that was not in the Onanparts kit?

[Handy Don 12,227]

8 minutes ago, WheelHorse520H said:

I learned that yesterday when I was on their site all the parts for Kohler and Onan were labeled for generators. The Onan ones were for the Cummins Onan RV generators. And they also had advertised brands like Generac.

 

The valves all seal, and I need a carb to intake manifold gasket, do I need anything else that was not in the Onanparts kit?

Cummins took over Onan but kept the brand active--hence the naming.

Many Generac generators use Onan engines.

[WheelHorse520H 708]

7 minutes ago, Handy Don said:

Cummins took over Onan but kept the brand active--hence the naming.

Many Generac generators use Onan engines.

I knew about the Cummins Onan buyout and later the rebranding but I did not know Generac had Onans. Learn something new everyday.

Edited July 14, 2021 by WheelHorse520H

[lynnmor 7,306]

13 minutes ago, WheelHorse520H said:

 

The valves all seal, and I need a carb to intake manifold gasket, do I need anything else that was not in the Onanparts kit?

 

The seal we are talking about is the oil seal on the intake valve stem.  Look at the back of the valve and see how much carbon buildup is there to get an idea of how well the oil is being controlled.  You should be OK with gaskets.

[WheelHorse520H 708]

Just now, lynnmor said:

 

The seal we are talking about is the oil seal on the intake valve stem.  Look at the back of the valve and see how much carbon buildup is there to get an idea of how well the oil is being controlled.  You should be OK with gaskets.

Oh, ok I thought the one that seals between the valve and the engine block. I will look at that the next time I am out there.

[WheelHorse520H 708]

The seals on the back of the intake valve is clean, no seals needed right?

[lynnmor 7,306]

39 minutes ago, WheelHorse520H said:

The seals on the back of the intake valve is clean, no seals needed right?

You can’t tell by looking at the seal, what you are looking for is a heavy, black substance caked on the valve.  Personally I don’t mess around when I have them tore down and simply remove the valves and grind them, then cut the seats and reinstall with fresh seals.  I understand that most don’t want to go that far and don’t have the tools to do it right, 

[WheelHorse520H 708]

1 hour ago, lynnmor said:

You can’t tell by looking at the seal, what you are looking for is a heavy, black substance caked on the valve.

Ok, let’s start from the beginning here, I am confused. I am looking in the little box under the spot the valve covers came off (the yellow circles), correct? Then I should look at the part of the valve stem that goes into the spring, right?

[lynnmor 7,306]

No, you can see the back side of the valve in that oval shaped hole just above your yellow circle.  I can see it in the photo but it isn’t quite clear enough to make a determination.  

[WheelHorse520H 708]

2 hours ago, lynnmor said:

No, you can see the back side of the valve in that oval shaped hole just above your yellow circle.  I can see it in the photo but it isn’t quite clear enough to make a determination.  

That would be the cause of my confusion, I was looking under the valve cover. Will check that out, but I was able to order the gaskets individually from Colburn power for only a couple of bucks more and I don’t have to wait a few weeks to order them.

[WheelHorse520H 708]

I looked at the seals and they are discolored but there is not a lot of buildup built up. On a completely unrelated note, on the muffler and heat shield I have a few spots that are still bare metal because- Well let’s just say the first painting was a learning experience. Should I sandblast them back to bare metal and start again or just blend some fresh paint in the less than perfect areas? Thanks in advance for the advice.

Andrew

[lynnmor 7,306]

As long as they are clean, keep on painting.

[WheelHorse520H 708]

7 minutes ago, lynnmor said:

As long as they are clean, keep on painting.

That’s what I planned but as you saw in the starter thread I am a fan of second opinions. Thanks for the advice,
Andrew

[WheelHorse520H 708]

I picked up some heavy duty oven cleaner this morning and cleaned the cylinder heads. Although there are a few spots that are dirty, should I worry about these and clean them more or not bother? Pictures below ⬇️ 
Also, I did make sure to not let the oven cleaner sit too long.

[lynnmor 7,306]

I would scrape off the black spots using a putty knife or small chisel, just don't gouge the gasket surface.  A little more oven cleaner in the spark plug holes might be good.