Cummins B series

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Cummin's Failure

When I had 330's I hadn't heard of any idler failures on the Bayliner Forum. What I experienced was failures with the Sherwood raw water pump. That's where I would focus my energy. Tony Athens has a replacement pump that is well worth changing to. I completely lost my pumps at around 800 hrs. I think you would have to be running large belt driven accessories to experience failure. Not many boats log 5000 hrs on their engines. 5000 / 100 average hr per year = 50 years of use.
 
Depends on how much access you have to the front of the engines.
The pulley failures maily happen to engines that are run at higher rpm often as in a planing hull.
You have 6 BT at 210 hp correct?
If it were me and I was worried I would simply replace with new stock ones.

I don't believe you have the pump that fails often. That is the 1700 series. I had one of those in my 6BTA 270 and mine was fine at 1000 hours when I sold that boat. (If it had failed I would have gotten one of the Seamax pumps).
 
Jay is an excellent Cummins guy and pretty well spot on but -----. I'm a PM anal guy, so if it were my boat both pump and pulley/idler would eventually be replaced with newer designs. A safe assumption is the PO of your vessel ran the engines at higher RPMs, so some TLC by the new owner is needed. You already know his inverter wiring design has let you down.

While you're on boatdiesel communicate with BillD, he knows all the tricks for both areas plus high temperature detection.
 
I'll explain my reply..
1) I sensed lots of hesitation by the poster with modifying the engine.
2) All the idler failures I've read about (and I've been reading Cummins forums for 15 years) have been on the 330 and 370 hp models and in planing boats that run up in the 2400+ rpm range. You won't be doing that with a 210 B in a trawler. I know lots of guys with 210s and they never have issues there.
Looks like the same arrangement in the older 6BT pickup truck engine, which I ran for many years and worked on several and they last a very long time (200K).

High temp detection is worth doing and there are lots of ways to go about it. Bill D is a great source if you do a search for his threads you'll get great info.
 
Thanks

Thanks for the advice. I think I will replace the idler pulley with the retrofit just for a cost effective peace of mind. The comment on the PO is not founded. He was very involved with this vessel and lived on it for several years cruising the Eastern Caribbean (Bahamas, Turks and Caicos, and Puerto Rico). He cruised the Eastern US as far as NY city. He had enough of boating and is now cruising the US in his RV. The inverter issue had nothing to do with him. This is not the first Xantrex inverter to fail for no reason and will not be the last.
 
I replaced the stock idler pulleys on both my 6B 330's for peace of mind. Rather easy. Call Brad at SBMAR (Tony's place) if you need help. I also replaced both Sherwood raw water pumps with SBMAR's, one because it was failing and the other for peace of mind.

There is lots of info on both of these issues on boatdiesel.com

I cruise at 2300 rpm when my wallets full.
 
I have pretty modest mechanical skills but found following Tony Athens' directions for the idler bolt upgrade easy to do. Also agree re: replacing the Sherwood pumps. Before I heard about the Seamax alternative, I installed a Sherwood 'major refit kit' to mine when they started to dribble. These lasted 4 years (just as Sherwood said) & for not much more than the cost of the kit and install labour I bought new SeaMax's: very happy. And ditto to above re: adding additional high-temp alarms....BillD's posts on BoatDiesel are comprehensive to say the least. All inexpensive and easy (and even interesting for those of us happy to learn new things mechanical) protection.
 
My 2003 6bt5.9 @ 220 Hp has about 2000 hrs on it no problems yet, either with the bolt or Sherwood pump, I did read about problems with both on the Boatdiesel site although I have never known anyone who has mentioned problems (out of the ordinary) with either. I did buy locally a 10 mm bolt to carry onboard figuring if the original were to shear I could at least change it out. I also carry a spare Shearwood pump. I normally run 1400-1600 rpm.
 
When I had 330's I hadn't heard of any idler failures on the Bayliner Forum. What I experienced was failures with the Sherwood raw water pump. That's where I would focus my energy. Tony Athens has a replacement pump that is well worth changing to. I completely lost my pumps at around 800 hrs. I think you would have to be running large belt driven accessories to experience failure. Not many boats log 5000 hrs on their engines. 5000 / 100 average hr per year = 50 years of use.

Replaced our leaking Sherwood 1700 series with one of Tony's Seamax pumps. Nice bit of kit. Very satisfied so far (3 years).
 
My 2003 6bt5.9 @ 220 Hp has about 2000 hrs on it no problems yet,..... I did buy locally a 10 mm bolt to carry onboard figuring if the original were to shear I could at least change it out. .


Steve: if you have gone to the trouble of buying the hi-tensile larger bolt, you really ought to put it in. If the original bolt does fail, you will need a lot more than a replacement bolt to put things right, according to the BoatDiesel guys. As said earlier, it is not a hard upgrade for a DIY project
 
For those that have Cummins B series engines have you installed the idler pulley retrofit recommended by Seaboard Marine. If so how big a project was it and was it as easy as it appears?
Idler Pulley Issues - Cummins 6BT / 6BTA 5.9

Never heard of this - 6BT's at 210-250 hp. This happens on the higher hp pushed 370hp, which don't last as long. I have had six of those 210-250 engines - and thousands of hours on them. And, an old Dodge 3500 with one natural aspirated engine w/450k mi without rebuild.
 
Replaced our leaking Sherwood 1700 series with one of Tony's Seamax pumps. Nice bit of kit. Very satisfied so far (3 years).

Do you still need to remove the front engine mount to remove the Seamax pump? A major design flaw on the 6BTA
 
As JLeonard says: "I don't believe you have the pump that fails often."

The 210/220 HP 6BT5.9 uses a small Sherwood M71 pump (1-1/4") that SeaBoard does not offer (presumably because it does not fail like the 17000 series on the higher horsepower engines).

My first pump went 3253 hours before I rebuilt it and placed it in reserve. The second pump is now at 2900 hours. I get around 750 hours on the impellers, and I've put in new backing plates and cams, but this is all normal maintenance.

The tensioner doesn't seem to be a problem either as long as you don't change out the 65A alternator for a high output alternator. The first one went around 2000 hours before it started making a little noise, the second one was just replaced with 4198 hours after it started making a little noise.

CPL 0742, cruise 1600-1800 rpm, now over 6000 hours.
 
Do you still need to remove the front engine mount to remove the Seamax pump? A major design flaw on the 6BTA

Nightcap: the pump access issue isn't directly related to the engine but to the engine mounts used. I have large mounts and no problem with pump access....but those using the smaller/standard mounts do have a problem.
 
Thanks AQB, I work on several here and they all have the small mounts it seems and one is VERY difficult to access, as well as the fuel cooler when all the hose ends rust out. It's a gamefisher so plenty of water through the engine room vents when they're backingdown on a marlin.
 
Do you still need to remove the front engine mount to remove the Seamax pump? A major design flaw on the 6BTA

Yes. At least you need to shift the mount upward IIRC. But I think that the Seamax may be removable without doing so.
 
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