NOTICE Yanmar 4BY2 OWNERS

[knotflying]

Long story short - due to a fuel pump failure on a fellow tug owner's 4by2 he noticed that one of the clamps that secure the fuel pump to the rear of the ECU panel (Port side near rear of engine) had failed. The strap separated at a rivet point that holds it to the panel. I decided to check mine and sure enough, broken. I asked another tug traveling with us (Gansett Ranger) to check his. Sure enough, broken. The other bracket seems to be secure so not an emergency right now, but I suggest others to check theirs. Three out of three seems like it may be a common issue.

 

[captstu]

Any chance of a photo so I can visualize the access?


Stuart Bell
Ranger 25: Shearwater
(561) 352-1796

 

[baz]

...snip... Three out of three seems like it may be a common issue.

Just for the record, can you state the age of each of the three engines/boats if you know this. It does seem that this is the result of vibration/fatigue and if all three are similar in age the fatigue aspect would be a reasonable causation.

 

[YukonRon]

Thanks for the heads-up. I will have to check mine; as soon as the weather warms up a bit. I can't fiddle with the boat at -20C. 🙁

 

[Crewdog]

Is this the fuel pump?

 

[Salty7]

Thanks for the heads up on this! I checked mine today, mine was built in 2012. The back of the ECM has four nuts spotwelded to it. Each of the two fuel pump mounting brackets is attached to the nuts via four allen head machine screws. All looks good, nothing broken or loose. Are you saying your brackets were riveted on, no machine screws or nuts welded on?

 

[BaylorU]

Following so I remember to check next time I’m at the boat...thanks for the heads up...that’s what makes groups like this awesome. 🙂

 

[CaspersCruiser]

I’m the 4BY2 owner that had the engine failure that was traced to a defective electric fuel pump. A replacement pump was procured, but when the failed pump was removed, it was discovered that BOTH clamps that secure the pump to the back of the ECU were cracked in an identical fashion at a flush rivet. Below is a picture of one of the broken clamps.



My boat is a 2012 R27 with 1100 hours.

 

[CaspersCruiser]

Is this the fuel pump?

Yes. The two clamps pictured are what secures the pump to the ECU. Both of the clamps on my boat cracked completely through at a flush rivet in an identical way.

 

[Salty7]

Ah, a picture speaks a thousand words! That is actually a spot weld, not a rivet. It definitely looks like metal fatigue from vibration. That is something we all need to keep an eye on. Please let us know how you repair it, I assume you will beef the bracket up, it looks like it is currently very thin walled and possibly aluminum, if that is the case it is the wrong material for the application, way too brittle. If you have something machined maybe several of us would like the stronger bracket? One easy option, I almost hate to mention, is copper plumbers tape to fashion simple brackets and attach the pump to the existing mounting spots. Wrapping some neoprene around the pump would give it a gentler life.

 

[scross]

Has anyone been able to get a Yanmar part number for these clamps yet?
And a source for getting replacements?

 

[rpmerrill]

My engine should be a good test case. I'll check it today.
It is a 2012 vintage and has over 1100 hours on it.
Fuel pump replaced in summer of 2016.
Stay tuned.

Should 6BY2 owners also be alerted?

 

[Crewdog]

Has anyone been able to get a Yanmar part number for these clamps yet?
And a source for getting replacements?

Here's the part nos. for the pump assy and bracket hardware:

 

[rpmerrill]

A couple photos are posted in my album. It is a tight location. The engine ECU would probably have to be dismounted to gain access.
I was able to get a (limited) look at the clamps. With over 1100 hours they looked fine. I don't believe they were replaced back in 2016 when the pump was replaced.

It is now on my list of things to watch.

 

[YukonRon]

Thanks for the pictures.
It's still too cold for me go poking around, but it's now on the top of my list. What is involved in removing the ECU for a good inspection of the pump clamps?

 

[rpmerrill]

Thanks for the pictures.
It's still too cold for me go poking around, but it's now on the top of my list. What is involved in removing the ECU for a good inspection of the pump clamps?

FIRST, consider driving the boat down to Florida......Everything else is easy!

 

[CaspersCruiser]

The part number for the clamp: 120650-51630 It is made from stainless steel and is fairly robust, but obviously vibration causes it to crack.

To answer a question from above posts: For best access, the ECU does need to be loosened from its mount. There are four bolts on the back of the ECU that secure it to a bracket with nuts. The forward lower nut is fairly difficult to access.

The clarify some information also posted above, the place where the brackets crack ARE rivets and not spot welds. Spot welding would be a better means to fasten the two parts since it would eliminate the holes drilled in them. The crack almost certainly starts in the rivet hole.

 

[YukonRon]

Thanks for the pictures.
It's still too cold for me go poking around, but it's now on the top of my list. What is involved in removing the ECU for a good inspection of the pump clamps?

FIRST, consider driving the boat down to Florida......Everything else is easy!

I wish!..but we are moving down to Vancouver Island this summer, so that will be a big improvement in the boating season. 😀
Has anyone looked at whether it would be feasible/beneficial to mount the fuel pump onto the engine instead of the ECU? It seems to me that a pump connected to steel lines being attached to a flexible plastic box is a recipe for vibration issues?

 

[rpmerrill]

Wrapping some neoprene around the pump would give it a gentler life.

I should have added a response to Salty.
The pump is cradled in a sleeve of pretty soft rubber, just guessing, about 1/4--3/16" thick.

Looks like a pretty comfy place.
But ya, I'd like to see it mounted on the wall somewhere.
(Not a crazy idea.)

 

[scross]

Just ordered a pair of these clamps for the spare parts bin. Four week lead time. I’ll check the existing clamps this spring. They were about $26 each plus shipping.