Yanmar nozzle protector removal help.

[Captain Bill]

I got my order of injector part number 729670-53100 and they are also 12mm across the clamp hold down area. Does anyone have any suggestions to find out what part number I really need to order with these engines? The engine serial numbers are A02302 and A02299 and say 3JH3E on the name plate. The date on them is 2001. Again, there are no part numbers on the injectors themselves. I cannot find any images on the net of actual Yanmar injectors as all of the actual parts show images of the box only. Looking at the parts catalog illustrations it looks to me like the 729270-53100 us the correct part number and I have the "epa" version of the engine. This is based on the type of clamp (retainer) in the illustration. The "slot" in the "EPA" retainer is oriented 90 degrees to the engine while the "non-EPA" versions are parallel to the engine. Unfortunately the parts catalog illustration of the injector shows the clamp surface having the same orientation which seems to be correct for a parallel orientation when installed in the engine. Granted these illustrations are not necessarily meant to be correct in detail, they're just not helpful. There is also a plate on the valve cover that says conforms to US and EPA emissions specification.



I finally got the nozzles clean enough to get some numbers off of them and they do not correspond to any of the numbers in the parts catalog. I am assuming that the nozzles were replaced when I had the injectors serviced previously.

[skipperpete]

Injector identification follows 2 different paths Bill, the first path is the engine manufacturers parts catalog number, from my book this means you have some choices.... (nozzles only). The first two engines are 3JH3E and 3JH3CE, both use nozzle p.n. 129468-53000 then follows the 3JH3E (EPA) which uses nozzle 129270-53000.
Theres another numbering system to enable techs to identify the precise characteristics of ANY nozzle and it only appears in the service manual ..... sometimes. For Yanmar injectors the code is as follows and is inscribed on the nozzle body .
Y DLL A -150 P 225TCO
Y - Yanmar
DLL..... semi long
A......Mounting angle in head
150.....spray angle
P....size
225TCO. ...Design code.
Theres a lot more info regarding the incremental changes Yanmar makes to all of the QM, GM/HM, JH, YM and LH series engines but you need a Rosetta stone to decipher the “changes”. For instance, after years of being told by Yanmar that they don’t make floating earth engines.... (and consequently doing my own conversions for Aluminium vessels) .... lo and behold, there in the 3JH parts catalog is the entire floating earth wiring harness and specialised components parts diagram..... EUREKA!

[Lowesmarine]

Hi Captain Bill, as far as I can make out your engine has the cast single bolt (8mm) injector hold down retainer. I have been unable the find a picture of the correct injector assembly to check orientation, but I have a part number which I think is the correct assembly. Part# 129270-53000.
I would talk to your parts supplier to confirm if the machined recess is inline to the return pipe leaving the injector which is 90' to the set of injectors you currently have. Regards David

[Captain Bill]

I finally got a thread rolling tap and it does cut threads in the protectors but they did not break loose. The tap wrench does not grip the tap strongly enough to pull it out even when tightened with a wrench. I figure the next step is to get a long bolt with the tap's threads and fashion a puller out of a large socket. I'm not holding my breath though. I have given up on buying new after market injectors. I have sent my originals off to have them rebuilt. I think that the aftermarket suppliers just don't deal with "EPA" engines. It here in the US It seems that though marketed as 3JH3CEs when attached to a sail drive they actually use the 3JH3E (EPA) engine. This is of course different that the rest of the world and not reflected in the parts catalog or service manual.

[Lowesmarine]

Hi Captain Bill, the nozzle protector is quite soft, sometimes they are burnt and deformed, this is the reason I use the coach bolt / screw. I have found that the stainless ones are quite Sharp with a coarse thread and grab the protector well. Sometimes a pry-bar under the head of the bolt maybe required to lift the protector out.
A reputable diesel injection shop should be able to match the numbers on the injector nozzle, Yanmar injectors usually need the nozzles cleaned and pressures reset about every 1000 hours, even if the engine is running / sounds good, sooner if the diesel quality is poor.
Regards
David

[Captain Bill]

I got an m8x1.25 tap. I can feel it making threads and cannot pull it out with the tap as I can't keep a strong enough grip on the tap with the tap handle so the threads appear to be well made as I put a pretty good amount of force on it before the handle slips off the tap. I bought an M8x1.25x110mm bolt to make a puller. The M8 bolt slides right through the protector! I've compared the tap and the bolt and the diameters look the same as well as the thread Pitch. Go figure. I was afraid to use an M10 tap because it was basically the same diameter as the outside of the protector and I was afraid of damaging the head. I guess the next step is a coach bolt. Ok, tried a 3/8 carriage (what we call a coach bolt here) bolt but it would not start, but the one I had was not stainless. M9 bolts are apparently a really rare item in the states. So the search goes on.

[Captain Bill]

I've had no success at all trying to remove the protectors, but I have made a new observation. It almost seems to me that they don't exist. It's clear to me that these things are supposed to be made of Teflon. I have now managed to clean some deposits off of the "protector" I am trying to remove and it appears to be metal and somewhat recessed into the injector hole when viewed from above. I am now beginning to think that these protectors were not installed the last time the injectors were serviced and what I am seeing is a shelf in the injector hole that the protector rests on. For anyone who might know, is there a metal "shelf" in the injector hole that the protector rests on and prevents the protector from entering the combustion chamber?