Bad vibration

[BATWELDING]

Good morning, I live in Haïti and we just bought a couple old used 802 gensets. The previous owner said the one ran well until it just quit. Anyway I took it apart and put new piston, rings and bearings in it. And of course all new seals. It starts and runs well but has a terrible vibration. I tried putting new injectors in but that didn’t make a difference. Anyway I’m just a backyard mechanic is there anything I missed or need to change? Any and all input is appreciated.

 

[BATWELDING]

Also I forgot to mention it is the Onan version of the Lister 2 cylinder

 

[Triple Jim]

It's probably normal. The 2-cylinder engines have the pistons going up and down together, so they vibrate a lot more than the 4-cylinder engines like the 803 has.

Maybe post a video and the guys here that have 802s can comment.

 

[BATWELDING]

https://share.icloud.com/photos/0efYqXzbDG--rn6RdgDqnG1MQ here’s a small video of it running I had a chain hooked to the top because there was no way it would sit in one place

 

[Triple Jim]

What am I seeing? It appears to be only an engine. I'd expect the engine to do a lot of shaking if it's not installed in the generator assembly.

 

[BATWELDING]

Yes I pulled the engine out and disconnected the generator head. I thought maybe something was out of ballance on the rotor. But the vibration is still there

 

[2Pbfeet]

Yes I pulled the engine out and disconnected the generator head. I thought maybe something was out of ballance on the rotor. But the vibration is still there

The 802 two cylinder diesel is well known for vibration.
With respect to your video, I would point out that having the engine loose on the floor with some of the weight on a lift chain isn't going to help, but is never going to be a smooth as an inline 4, V-8, or an engine with a counterbalancing shaft.

All the best,

2Pbfeet

 

[cstumpf750]

https://share.icloud.com/photos/0efYqXzbDG--rn6RdgDqnG1MQ here’s a small video of it running I had a chain hooked to the top because there was no way it would sit in one place

That looks normal for a parallel twin with no balance shaft. They are essentially a vertical paint shaker. A good example is an old Triumph motorcycle with a parallel twin. They practically bounce the front tire off the ground idling at a stop light and buzz like crazy at all other rpms. There is a thread somewhere on here where someone found a height difference with the rubber mounts and shimming eliminated a lot of the vibration. The 802s are prone to “walking” if sitting on their own. If they are on a trailer, the tire will absorb a lot of the vibrations.

 

[Guyfang]

Put it back together. Check the vibration idolaters and start it up. THEN take a video.