DN2M / DN4M engine experts, a Q about stuck rings.

[Digger556]

My first generator was a 802a I snagged off CL for $800. It's older, a 1994 model, but low hours (221 hrs) and decent shape for its age.

However, its always been slightly down on power and based on cold start, full load performance, blowby, etc, I would guess it's lost some compression. My first thought was stuck rings, but I was curious if there was an outward of determining stuck rings from broken rings?

Honestly, it's probably fine being a backup unit, but it would be great to get it in top running condition.

 

[Scoobyshep]

My first generator was a 802a I snagged off CL for $800. It's older, a 1994 model, but low hours (221 hrs) and decent shape for its age.

However, its always been slightly down on power and based on cold start, full load performance, blowby, etc, I would guess it's lost some compression. My first thought was stuck rings, but I was curious if there was an outward of determining stuck rings from broken rings?

Honestly, it's probably fine being a backup unit, but it would be great to get it in top running condition.

Stuck rings typically can unstick and improve, that's about the only difference I can think of

 

[Digger556]

Stuck rings typically can unstick and improve, that's about the only difference I can think of

That's what I'm hoping to get out of this. It's not bad enough to tear the engine down.

Would stuck rings burn more oil or have lower compression than a broken ring? (given other conditions remain the same)

One other bit of information, when a large load is applied, the engine smokes a lot (black), but slowly subsides as the heat builds. I've been assuming this is because the piston is expanding and closing the gap not covered well by the rings.

 

[98G]

That's what I'm hoping to get out of this. It's not bad enough to tear the engine down.

Would stuck rings burn more oil or have lower compression than a broken ring? (given other conditions remain the same)

One other bit of information, when a large load is applied, the engine smokes a lot (black), but slowly subsides as the heat builds. I've been assuming this is because the piston is expanding and closing the gap not covered well by the rings.

What's the longest you've ran it above 75% load?

 

[Digger556]

1-2 hours at a time, every 1-2 months.

 

[98G]

Any signs of wetstacking?

 

[Digger556]

No signs, exhaust is dry with soot similar to my 3 other units.