Cummins 4bta opinions

captchuck

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26' Seaway
Looking for some opinions prepared to make an offer on one 250hp 700hrs 1.5:1 gear harness and panel. Anything particular I should look for? Be aware of with these motors or when looking at any used diesel. My father has 6bta s in his boat and he's been happy. But this will be the first time I am looking to buy a diesel that is not in a boat and I'm a little shy on experience in such especially what to value them at and not being able to run them under stress etc...
 

captainlarry84

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KristenFormer Charter Captain
Buying a used motor without it running can be a real danger. I would proceed with caution. You real need to bench run the motor. To install it without a stand test is a big gamble. When we sell them we mount the motors on stands, hook up the panel introduce a source of cooling water, usually a hose just feeding into the raw water pump. If this cannot be done minimally a compression test, which require injector removal.

Do you have any history on the motor? Why was it removed with only 700 hours with the gear? If none of this can be done then at least bar the motor over to make sure it is not seized. Also carefully examine all fluids. Make sure the gear oil is free of water and clear.
Examine the coolant it should be nice and reddish pink in color with no brown traces. It is always good to drain a little coolant from a low spot on the motor. Motor oil also free of any coolant. Removing the valve cover also is a good idea when you bar the motor over.

Examine the paint carefully for touch-ups that might hide brownish paint from an overheat. Also pull the end cap off the heat exchanger and give that a good look. Stick your finger in the turbo and see if the vanes spin freely.

Lastly if you can I would consider pulling off the head. With that removed and a hand spin most of the major components can be looked at.

In closing if this is beyond what you feel you can do, pay a Cummins Merchanic to look the motor over as best he can. Still a gamble
 
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captchuck

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Thanks Larry the motor came from a boat that was reportedly beet around during sandy but suffered no water intrusion . I will be able to hear it run etc and check fluids. You have any suggestions or guidelines on how to put a value on something like this.
 

BillD

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25 Terry Jason with Cummins 370 power
Looking for some opinions prepared to make an offer on one 250hp 700hrs 1.5:1 gear harness and panel. Anything particular I should look for? Be aware of with these motors or when looking at any used diesel. My father has 6bta s in his boat and he's been happy. But this will be the first time I am looking to buy a diesel that is not in a boat and I'm a little shy on experience in such especially what to value them at and not being able to run them under stress etc...

Capt,

I have a pr. of 6BTAs in my Blackfin. Love the Cummins 6B/BTAs.

I'll pass this along. I have not "felt" it 1st hand but "word on the water" is when you take 2 cylinders off of a smooth as silk 6B the now 4B becomes a rattler/shaker.

The 4BTA is as rugged and tough as the 6BTA but you'll want to consider vibration isolating mounts.

Again, "word on the water", take it for what's worth !

Bill D
 

eyschulman

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seattle
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Devlin 48 & Marshal Sanderling
Go to boatdiesel.com and look up posts on that motor. Some of the Cummins/murcruser smaller motors had bad reps I don't know if this is one of the good guys or a bad one. With a bt designation probably a good guy.
 

traditions

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That's kind of strung out for a 4 cylinder.They do shake at idle,but when you throttle up it goes away.They are tough at normal 130 ish HP,not sure of actual HP,but I have seen them with a lot of hours.
 

BillD

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25 Terry Jason with Cummins 370 power
Go to boatdiesel.com and look up posts on that motor. Some of the Cummins/murcruser smaller motors had bad reps I don't know if this is one of the good guys or a bad one. With a bt designation probably a good guy.

Eys,

Cummins/Mercuiser.

Cummins ALWAYS produced the big displacement iron motors.

The "diesel Mercs" in the joint venture are the junk out there. Small liter high hp high rpm with aluminum head and or block. These engines just can't dissipate the heat generated by the engine loads demanded in a boat.

I would NOT be hesitant to install a Cummins 4BTA in a small DE. Problem is even as a RECON they were expensive.
 

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