Cummins 6 BTA won't run

[Steve Bode]

I have a twin screw fly bridge 34′ powered by Cummins 6 BTA, I was recently underway at about 2,600 rpm when the starboard engine lost power, and after about 1 minute quit all together. It had oil pressure and normal temp when it quit. I knock a little before quitting. There was no color of smoke noted. It will not crank back and sounds like it is out of time the way is sounds when it rolls over.
One guy had me replace the lift/injector primer because it was leaking fuel. I have done that and bled injectors still sounds the same. I replaced starter still sounds the same and won’t crank. I pulled all the valve covers off and all rocker arms are going up and down. I have pulled hose off of air intake just before aftercooler and when I spin it over seems like exhaust is coming out of air intake. I have also used ether and on first couple of spins tries to crank then won’t. Fuel filters have been changed and racors rebuilt. Batteries tested and are great. Port engine when disconnecting fuel solenoid it spins very fast on same batteries.
On the front of the engine pulled cover off to check if bearing in alternator or something was froze up, but every thing spins freely.
Anybody have any suggestions.

Topic

[Stephen Oliver]

Hi Steve

Yes – nice boats – I looked at several prior to buying mine. Made on the eastern Side of Australia and one of the few manufacturers here that made an impression abroad. I have a western made boat built for the interesting seas we get here! (narrow beam, deep v and heavy to take a beating – 2-3m or 6-10ft swells are normal and what we go out in)

Re the solenoid – check here https://www.sbmar.com/?post_type=post&s=solenoid Tony has several posts relating to testing wiring etc.. certainly worth a look. If its turning over real slow it could also be a voltage issue and the solenoid not pulling back because of it – I had the same issue on my port motor – solved by cleaning up wiring and eventually rewiring the whole battery circuit.

Steve

[Steve Bode]

Good morning Steve from Australia, my boat was actually made there, it is a Riviera. Yes I have checked it and it does get warm and move to shut off and I am guess it is mechanical only and does not do anything electronic ??? And yes that will be my project today after checking compression is to pull exhaust off and make sure nothing is blocking it.
They way it quit under power was like someone just shut something off.

[Stephen Oliver]

Have you checked fuel solenoid, they are pull to run if it’s a Bosch pump may have burned out if it wasn’t pulling and holding. There is a post on the Tony’s tips section that covers this..

Have you checked wet exhaust hasn’t delaminated anywhere blocking the exhaust?

Just some more cheap easy options..

Steve

[Steve Bode]

It rolls over slow sounds like a car with a banana in the tail pipe if you can imagine that. Exhaust coming out air intake where I pulled it off from the after cooler is also concerning. Seems to make bubbles out the back and exhaust does not seem to have water in it. Wondering could there be some type of emergency shut down that might have for some reason activated. I will be checking compression in the morning and will get some pictures up.

[Philip]

Are you getting any smoke from exhaust when cranking? Have you tried pumping while attemptimg to start? Have you tried a small fuel tank right to the engine bypassing boat tank/hose/valves?

When you say it spins like it’s out of time, does that mean it spins fast like no compression? If so have you checked for bubbles in coolant expansion tank to rule out a head gasket.

Got any pictures of the engine from all sides and angles? Maybe we can spot something.

Phil

[Steve Bode]

First pumped up the manual button on lift pump and while holding down loosened fitting til all air came out. Then with 19 mm wrench loosened injector lines at injector and had someone spin motor over till I got a steady stream of diesel then tightened them back

[Philip]

How did you bleed injectors?

[Author]

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