NOTICE Yanmar 4BY2 OWNERS

[Boatdreamer]

Thanks for the heads-up. I just checked the clamps on Gratitude and it looks like the top one is definitely broken but the bottom looks OK. She’s a 2012 with about 450 hours on her. I’ll be placing an order for two next week at Shearwater Marine in Stuart unless someone know a place I can order them and have them sent to our house. It’s information like this that makes our community so great!

Tim and Donna
Gratitude R27
Yanmar 4BY2-180

 

[nzfisher]

Just checked my clamps- appear ok but did not take the thing apart for a proper inspection. That being said, at least one of the rubber vibration mounting fasteners is broken that connects the ecu to the engine. Does anyone have a part number for these cuties? I get the expediency packaging, motor electronics, fuel pump are a bolt in for third party users but, as my upper Michigan ancestors used to see “ah geeezz”. How could this stuff not rattle itself to death as the motor mounts get old, the drive line begins to vibrate, the starting torque takes its toll, etc.?

 

[blifland]

Yanmar #: 120650-75450 MOUNT, RUBBER (metal parts are stainless steel)

our 2011 RT25SC 4BY2-150 380 engine hours:

Just took apart ECU/fuel pump assemblies: clamps - no cracks but the hard plastic spacer on clamp adjustment bolts were half gone (bottom half) looked like they were OK from top until I unscrewed the adjustment bolts and spacer parts fell out (what was left of each).

ECU rubber mounts: upper left: completely broken in half. Upper right: fatigue crack halfway thru.
bottoms: both had multiple fatigue cracks. Found a company i NY that had original mounts: but they wanted 18.30 each plus $50 fee 'cause order under $500.

Will try Yanmar dealers for parts. I have same size but non-stainless and not metric mounts: from MSC:
36691152 4.46 each MAX LOAD 70LBS STUD/STUD MOUNT 1/4"THD
and might paint with zinc paint or other anti-rust anti-corrosive coatings and use.

 

[nzfisher]

Thanks for that information on the rubber mounts.

 

[Salty7]

Thoroughly checked my ECU/Fuel pump mounting hardware this weekend. 2012 4BY2-150 now has 135 hours - Pump clamps - no cracks but rivets are slightly loose, the rubber sleeve around the pump puts them in tension but the rivets are slightly loose so vibration has been enlarging the holes in the brackets. Both hard plastic spacers on the clamp bolts are cracked. Those of you with broken brackets - can you tell if the rivets were loose on your brackets?

The rubber ECU mounts - top left (aft upper) is cracked, the other three look dried out from heat.

I can't help but think anyone replacing these pump clamps should consider welding them so the rivets don't carry all the load. Vibration has significant energy and there is a big load placed on those little rivets. I think that all four rubber ECU mounts should be replaced at once because it looks to me like the material dries out with time and heat. If the hard plastic, cracked, spacer falls out then the pump comes loose. Yanmar really needs to engineer a permanent fix for these issues. IMHO the best fix of all would be for the entire ECU to come off the engine block and be mounted to the boat.

Also, I have mentioned before, everyone with one of these engines - make sure the hose from your turbo to waste gate actuator is attached. Despite clamping it firmly mine had fallen off again because the original hose from Yanmar was too short. I replaced the hose with one almost twice as long so it isn't constantly vibrated off by the air cleaner assembly.

 

[Brian B]

I just completed replacing both clamps. Both were completely broken and the rivets were tight, no wear at the rivets. I replaced both upper ECU rubber mounts, one was split all the way through, one was cracked. Lower rubber mounts were fine. The nuts on the lower mounts only have to be loosened, the ECU will slide off the bottom. Even though the clamps were broken there was no movement in the pump at all.
It was mentioned on another post that the new clamp mounting holes are off by about 1/8" compared to the old ones. I found this to be the case and I elongated the holes with a 5/16" bit to allow the holes to align with the welded nuts on the ECU.

 

[blifland]

Questions to those of you that loosened the ECU to examine or replace the rubber mounts and/or the clamps and if you unscrewed the banjo bolts on the pump:
what did you use to replace the crush gaskets? my boat had aluminum ID 12mm X OD 17mm x 1mm thick. Yanmar says they only have 3 in the USA ($ 6 ea). I have some copper ones same size except they are only about .75mm thick. Have some aluminum ones arriving soon ID 12mm X OD 16mm x 1mm thick and some copper ones soon ID 12mm X OD 18mm x 1mm thick. which would you use?
What did you use for the rubber stud mounts? Yanmar says they are not sure that they have stainless steel like the originals and are checking on it - supposed to get back to me.
I have the MSC 1 inch rubber mounts (not stainless though) and could coat with high temp Rustoleum or zinc paint - maybe 2 of one and 2 of the other if Yanmar cannot supply stainless.
Yanmar says it does not have the spacers on the clamps and to go ahead and use similar size nylon ones I have.
Thanks, Barry L

 

[Brian B]

Questions to those of you that loosened the ECU to examine or replace the rubber mounts and/or the clamps and if you unscrewed the banjo bolts on the pump:
what did you use to replace the crush gaskets? my boat had aluminum ID 12mm X OD 17mm x 1mm thick. Yanmar says they only have 3 in the USA ($ 6 ea). I have some copper ones same size except they are only about .75mm thick. Have some aluminum ones arriving soon ID 12mm X OD 16mm x 1mm thick and some copper ones soon ID 12mm X OD 18mm x 1mm thick. which would you use?
What did you use for the rubber stud mounts? Yanmar says they are not sure that they have stainless steel like the originals and are checking on it - supposed to get back to me.
I have the MSC 1 inch rubber mounts (not stainless though) and could coat with high temp Rustoleum or zinc paint - maybe 2 of one and 2 of the other if Yanmar cannot supply stainless.
Thanks, Barry L

I unscrewed one banjo fitting going from the top of the pump to the fuel filter head, I reused the washer. I will be keeping an eye on it in case of a leak. The Yanmar part # for the washer is 120640-01300 size is 12x1.5 according to the parts manual. I believe it is aluminum.
I had no trouble getting the Yanmar rubber mounts that have SS studs.
As I said in a previous post with both clamps broken there was no movement at all in the pump assembly. The boat is 9 years old with over 1100 hours. I have no idea how long it had been operating with the broken clamps.

 

[blifland]

FYI...I ordered and received 4 rubber mounts from Yanmar - 17.95 + 1.52 tax each - but the studs are NOT stainless steel.
Sent a note to Yanmar - about my disappointment RE non-stainless steel on boat engines - not holding breath for a reply.
Guess the ones from MSC will work just as good as the pricey Yanmar ones - Oh well - I have spares now.
The aluminum banjo gaskets were 4.95 + .42 tax each; not the end of the world but still a crazy cost.