Onan Injector Gasket

[chris piazza]

This winter I pulled a bad injector from my Onan and had it rebuilt, of course now after several months I went to install it and forgot how the sequence of the gaskets go on the injector. I have one thin copper, one heat sheid and two thick spacers. My Onan manual does not show it. I guess I could pull a different injector to see but I am being a little lazy and thought it would be easier to ask.

Chris
Superior Nights 53C

 

[Avenger]

From the injector towards the head: Copper washer, thick Washer, insulator, thick washer.

 

[chris piazza]

Thanks Derek! I knew you would have the answer.

Chris
Superior Nights 53C

 

[Avenger]

You're welcome. Please tell me you ran something through that injector and that it wasn't a nozzle failure.

 

[chris piazza]

ok I won't tell you!, I dont know but I may have another problem. I put the injector back in (with a new copper gasket) but I had the same results, black smoke out of the hole. Could this be something else? Stuck exhaust valve? or do i change the the heat shield and the spacers too?


chris
Superior Nights 53C

 

[Avenger]

When you say "out of the hole" do you mean the hole that the injector goes in, or that cylinder is producing black exhaust smoke?

 

[chris piazza]

Out the Injector hole, looks like exhaust gases. I'm thinking the spacers may be bad. They have a couple of VERY small scratches on them. I think the injector may be not seated right?? Two bolts holding the injector, tightened down to 18lbs

Chris
Superior Nights 53C

 

[Avenger]

Definitely not seated right. Torque sounds about right, so it's time to break out the flashlight and inspection mirror and see what's going on in there.

 

[Canuck Dennis]

I would go on line and get the picture of your particular genset injector installation, mine has one gasket only, a copper washer, thats an Onan 20 KW MDKAE

 

[chris piazza]

Thanks Dennis but mine have four gaskets, I had just forgot how they go on. I think I will order they two spacers, heat shield and another copper gaskets just to be sure. Derek I did look into the hole and did not see anything unusual, of course I don't know what to look for.

Chris
Superior Nights 53C

 

[Avenger]

You're just looking to see that the seating surface is clean and smooth without scratches, dents, dings, carbon chunks, cracks etc.

 

[REBrueckner]

Chris, you wiped off the engine surface with a rag where the gaskets seat?? A small bit of debris might prevent a good seat.

Are those gasket washers Chris is referring to normally replaced when an injector is removed??

 

[Avenger]

Ideally the copper washers should be replaced every time, but in the real world one can sometimes get away with recycling them once.

BTW Chris, Do you have the larger copper washer that goes in the head in front of the heatshield installed?

 

[chris piazza]

No all I have is one small copper gasket that goes on the injector first followed by the two thick steel gaskets with the asbestos gasket between. When I stopped at the parts store I gave him the parts number for the copper gasket and he brought out one that was bigger than the one I had. I wonder now if I should have one of those that goes in the hole first. I did look in the hole and it appeared to look smooth and clean at the base.

Chris
Superior Nights 53C

 

[Avenger]

There's supposed to be a larger copper that approximately matches the outside diameter of the big heat shield washers. That one goes in first, then stack the rest of the components as earlier.

 

[chris piazza]

Yup your right. I just found it in my parts manual, called a shield to head gasket copper. When I removed the injector last Nov. I must have misplaced that gasket and forgot about it. Senior moment, after all I just turned 55 and retired this year!

Chris
Superior Nights 53C

 

[Avenger]

55 and retired.... You lucky so 'n so.

 

[chris piazza]

Put in the copper gasket this morning, all is good! I guess I should pay more attention when taking things apart!

Chris
Superior Nights 53C

 

[Avenger]

I'm glad that worked out.

Did you do the timing on that thing yet?

 

[chris piazza]

I set it with the port closing and pinning the injector pump, I did not do the flow method. I should get around to doing it correctly but it runs good just smokes alittle.

Chris
Superior Nights 53C