Cummins QSK - 19 Experts

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mikehar

Senior Member
Joined
Nov 3, 2019
Messages
153
Location
USA
Vessel Name
Gallivant
Vessel Make
Northern Marine 64
Does anyone have experience with this engine? I'm looking at a boat that has this engine. It's a big beast, much larger than other engines I've had with similar specs. This is a 1800rpm engine the produces 660hp. Above 1500rpm it starts to move. At 1800 rpm it's moving a lot. Some have told me that this is because of the mass of this type of engine. That doesn't seem right to me... Below 1500rpm it's smooth. To me, this feels like an alignment, shaft of prop issue. Thoughts?
 
Does anyone have experience with this engine? I'm looking at a boat that has this engine. It's a big beast, much larger than other engines I've had with similar specs. This is a 1800rpm engine the produces 660hp. Above 1500rpm it starts to move. At 1800 rpm it's moving a lot. Some have told me that this is because of the mass of this type of engine. That doesn't seem right to me... Below 1500rpm it's smooth. To me, this feels like an alignment, shaft of prop issue. Thoughts?
Have you tried Mike McNeill or Terry Wheeler? Mike is in Tacoma. Terry primarily serves the commercial fishing fleet out of Toledo, Oregon. PM me and I can give you phone numbers if you want.
 
The QSK is an inline 6 cyl which should run smooth at all rpm’s. Maybe a cylinder isn’t firing and it shows up at higher rpm’s and loads.

Join the forum at Sbmar.com where the Cummins experts hang out and ask for their help.

David
 
To me having a large mass engine it would make sense that it should not shake as much as a lighter engine.
 
This is a common engine in commercial trucks & fishing boats. It's also used on many generators, and that means it runs smooth. Vibrating at full rpm can be several things. Alignment, bad motor mounts, injector(s) not functioning properly at speed, air or exhaust restriction, bent shaft, bent prop, and so on.
Before buying you need to have an experienced mechanic look at it and a knowledgeable person check the alignment. Misalignment can cause expensive problems.
 
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