MEP-803a weeping fuel

[hammick]

Got the 803a I won fired up today. It runs great but it is weeping fuel around the head. I was only able to get it up to 60% with the heat guns and lights I had available. Going to use some space heaters to get it to 100%

I have attached a photo of the fuel weeping. Is this likely to resolve itself after repeated heat cycles?

How hard is it to install a new head gasket? Mine's an '07 model with 623 hours.

 

[jamawieb]

I'm 99% sure its not your head gasket if its fuel you're seeing. It's more than likely the return lines on the injectors. They are prone to fail and leak fuel down the back and side of the head.

 

[Daybreak]

Howdy,
Go through the linked topics in the MEP-8xx series Replacement parts thread.

It probably is the fuel return lines along the top of the engine.

 

[indy76]

I just picked up my 803a and the return lines were leaking terribly. Past the point of weeping. Found a guy on Ebay out of MD that has 3.5mm braided yellow stripe return lines. I got 6 feet and I was fine. I did not need to replace the long piece though. The one at the top of the head to the rear of the motor that runs back to the fuel tank was ok. I just cut it back 5 inches and it was fine. There was plenty of slack in that one for some reason.

 

[hammick]

Thanks for the responses guys. I had a chance to look at my 803a today and indeed the return line on top of the motor is leaking. Seems like it is just oozing out of the fabric covered line between two of the nipples.

How fragile are the return line nipples on top of the motor? I tried to disconnect the leaking line but didn't want to break the nipple? Is it best to remove the top to make this repair? I'm going to look for the return line on Ebay.

Do I just cut to length and push onto the nipple? Mine doesn't have any clamps.

Thanks.

 

[indy76]

There are 4 T connectors at the top of the motor, one for each cylinder. There are 4 vertical lines also that connect to the ones that run horizontal across the top of the motor. Those braided lines are maybe 1/2 in long. I pulled them all off. They can be fragile due to heat exposure. I just took the old lines put them next to the new lines and cut with a razor for a nice clean cut. I did not take the top cover off. The middle one is tight but it can be done. It's a 45 min job.

 

[indy76]

Oh, they are push on. No clamps needed.

 

[indy76]

Here is a pic of my old lines.

 

[indy76]

 

[hammick]

Thanks Indy. I just bought three feet of return line in Ebay.

Did you slice the lines with a razor blade to get them off or just work them off with needle nose?

 

[indy76]

I used my hands. I was really worried about breaking one of the plastic T's. I pulled the 2 end lines first then I pulled the vertical ones up and slid the top ones off. I used the needle nose to connect the top middle one back together. It was tight under the exhaust.

 

[hammick]

Thanks. I assume if I break a plastic tee then the lid has to come off. I think I read that the plastic tees are the same as sprinkler tees.

 

[hammick]

Indy does the plastic return line tee screw into the top of the motor or does it connect to something that comes out of the motor? I won't be able to look at my genset for a few days.

Also if I try to put a cut in the hose to make it easier to remove I guess I risk damaging one of the tees?

Thanks.

 

[JRM]

seems like the gen sets with a few thousand hours don't weep- wonder if the stale fuel causes it?

 

[Daybreak]

Howdy,
Weeping fuel return lines.
Known as yellow stripe fuel return line (vw, Mercedes, etc...) 3.5mm inside diameter, pushes onto the hose barbs on the tees

Fuel return line thread

I wanted to make things easier and save the tees. I simply sliced the old lines. Removed the old lines and tees. Outside in a good grip, and pulled off the old hose.

fuel return lines age a few ways. lack of use, dry rot, JP8, heat, lots of use.