DN4M pistons

[loosegravel]

Well, instead of waiting to locate a different fuel pump for this unit I robbed Peter to Pay Paul. I “borrowed “ one out of my personal stand-by 10kw unit. Once the fuel system was primed it lit off. I let it run for about 10 minutes with no load. Then I began with a 25% load for about 30 minutes. Then 50% for another hour or so. I must admit. It kind of freaked me out seeing glowing embers coming out of the exhaust When I pulled the head on this thing I didn’t remove the intake or exhaust manifolds. I can only assume (and hope!) that the exhaust manifold had a bunch of carbon in it just like the pistons looked like when I pulled them out. All of that crap was coming out when I had it under a load. At any rate, the exhaust cleared up nicely and it ran pretty good. I did have some issues getting 60hz under a load. I confirmed the gauge reading by using my Fluke. It was right on. So I grabbed my box end 8mm wrench and adjusted the bolt allowing the engine rpm to increase enough to get the hz up to 60 under a load. One thing that I’m not sure about is I’m wondering where I am as far as correct fuel pump adjustment is concerned. I reinstalled the shims that came out with each on the pumps into their perspective holes. But, because I had all of them out at the same time I should probably go through the correct adjustment process, which includes removing the gear cover and using “the special tool” they mention in the TM. Does any body have a different method that works for you. Thanks!

 

[loosegravel]

Well, instead of waiting to locate a different fuel pump for this unit I robbed Peter to Pay Paul. I “borrowed “ one out of my personal stand-by 10kw unit. Once the fuel system was primed it lit off. I let it run for about 10 minutes with no load. Then I began with a 25% load for about 30 minutes. Then 50% for another hour or so. I must admit. It kind of freaked me out seeing glowing embers coming out of the exhaust When I pulled the head on this thing I didn’t remove the intake or exhaust manifolds. I can only assume (and hope!) that the exhaust manifold had a bunch of carbon in it just like the pistons looked like when I pulled them out. All of that crap was coming out when I had it under a load. At any rate, the exhaust cleared up nicely and it ran pretty good. I did have some issues getting 60hz under a load. I confirmed the gauge reading by using my Fluke. It was right on. So I grabbed my box end 8mm wrench and adjusted the bolt allowing the engine rpm to increase enough to get the hz up to 60 under a load. One thing that I’m not sure about is I’m wondering where I am as far as correct fuel pump adjustment is concerned. I reinstalled the shims that came out with each on the pumps into their perspective holes. But, because I had all of them out at the same time I should probably go through the correct adjustment process, which includes removing the gear cover and using “the special tool” they mention in the TM. Does any body have a different method that works for you. Thanks!View attachment 863325View attachment 863327View attachment 863328View attachment 863329View attachment 863330View attachment 863331

I might add here that I'm still unsure what wiped out these pistons. Afterall, that's what this tread was about. My gut is still leading me to believe that severe carbon build-up from wet-stacking was the culprit here. I know that this is hard to believe, but I really have no other explanation. Yes I had piston ring seizures but what was the cause of that? Three of the 4 pistons were leaving deposits on the cylinder walls. I double checked to high temperature shut down today when I had this thing running. It shuts it right down when I jump the two wires on the normally opened switch. I also checked the low oil shut down as well. No issues there. There was virtually no wear on the rod bearings so I reused them. It's a mystery to me

 

[jamawieb]

Yes you can't have the pistons at TDC when installing the head. With a used motor you have to wait 45 minutes after torquing the rockers to re-torque for the hydraulic lifters.
The broken arm on the injector pump is crazy because when I first started dealing with them , I bent the crap out of one because it wasnt lined up correctly. I put a lot of pressure on it LOL!.
The carbon and ambers is common, don't worry about that.
May want to look at adjusting the governor because the broken arm on the injector pump could have caused the governor springs to expand getting it out of adjustment. I have a couple of used pumps sitting around, I'll be glad to send you. PM your info to me.

 

[loosegravel]

Yes you can't have the pistons at TDC when installing the head. With a used motor you have to wait 45 minutes after torquing the rockers to re-torque for the hydraulic lifters.
The broken arm on the injector pump is crazy because when I first started dealing with them , I bent the crap out of one because it wasnt lined up correctly. I put a lot of pressure on it LOL!.
The carbon and ambers is common, don't worry about that.
May want to look at adjusting the governor because the broken arm on the injector pump could have caused the governor springs to expand getting it out of adjustment. I have a couple of used pumps sitting around, I'll be glad to send you. PM your info to me.

Thank you sir! PM sent. Here’s a photo of the broken spool valve on this pump. Even if the one you want to sell me is all rusted up I’m pretty confident that I can use the spool valve from yours and make this one I have work just fine!

 

[jmenende]

I had to swap engines today. I must say that installing the engine with the genhead on and sliding it in is by far easier than the old method of seperating the genhead from the engine while still bolted to the chasis. Luckily i had this one that came from gp auction in crate that was good. The one being replaced destroyed itself and it was a reset engine. The connecting rods were all banged up. I dont like resets imho. I had to tear down the old one for parts. Its was veeeery rusted and had a crack in a wall liner.

 

[loosegravel]

I had to swap engines today. I must say that installing the engine with the genhead on and sliding it in is by far easier than the old method of seperating the genhead from the engine while still bolted to the chasis. Luckily i had this one that came from gp auction in crate that was good. The one being replaced destroyed itself and it was a reset engine. The connecting rods were all banged up. I dont like resets imho. I had to tear down the old one for parts. Its was veeeery rusted and had a crack in a wall liner.

That’s exactly how I did the one last year. I’m also fortunate to have an overhead hoist on a sliding I-beam. It makes those jobs very nice to do. Good work

 

[jmenende]

That’s exactly how I did the one last year. I’m also fortunate to have an overhead hoist on a sliding I-beam. It makes those jobs very nice to do. Good work

Funny, i actually have same setup. My gantry crane with a hoist makes it a breeze. The pallet jack helps to slide. Another way would be an engine hoist. Either way its a 2 man job to avoid damaging the chasis and enclosure.

 

[loosegravel]

Funny, i actually have same setup. My gantry crane with a hoist makes it a breeze. The pallet jack helps to slide. Another way would be an engine hoist. Either way its a 2 man job to avoid damaging the chasis and enclosure.

The first time I pulled them both like you did was a few years ago. I had an 803A that was leaking oil really bad from between the engine and the gen head. My suspicions were correct. The rear crankshaft shaft seal was leaking. Like you mentioned, it’s so much easier to split them apart when they’re out in the open, on a heavy table or something up higher to support them. I have a big heavy welding table on four casters that I use for stuff like that. I can roll it right under the engine and generator head. I also drop subframes with engines and transaxles in them out from cars that way. My knees and my back give me hell anymore if I’m down on the floor for too long. Even laying on a creeper has lost its appeal to me.

 

[Guyfang]

It doesn't matter what size gen set, pulling the engine and main gen is simply easier.