Changing injectors isn't tough, just be as fanatically clean about it as you can. It's only a little bit harder than changing spark plugs, and mostly because you will need to bleed the fuel lines after the replacement.
I have never done it on a Yanmar, but a I have a story that might have relevance...
On my old boat I had a 40 year old BMC diesel with standard Bosch injectors. The service manual described in detail how to pull the injectors using the special tool, that of course was no longer available. I approached the task with much wimpering (as you uncle would say!).
After removing the two nuts that secured each injector and disconnecting the fuel header, I puzzled over how to jury rig a pulling tool to get them out. After much head scratching and fussing I tried an experiment using tools I already had...
Each one come out using two fingers... Sometimes, things are as easy as we wish they always were!
Somewhere around Eleuthera, Bahamas
Hello Amelians- Would love to get advice, so please indulge me. Situation: I'm in Martinique, three weeks from heading to Bonaire for hurricane season.........then Aruba, Columbia, Panama, and through the canal......i.e. about to head away from the island chain and abundant technical support.
Through owning L'ORIENT (SM2K #422) for 8 years (and being cheap), I've become fairly technically competent with the boat and haven't paid for a technician in years.........and owe a lot to the posts I've read here for that. While not every repair has been smooth I've found the answer is always in this site. In maintaining the boat, I try to balance opposing cliches......."don't fix it if it isn't broken"........and "you can't be afraid of your boat".
So, the other day I decide to test the engine and attempt to get the revs up while motoring...........can't get above 1900 RPM. No big deal........it must be a dirty prop, like always..........so I dive on the prop and find some peach fuzz and a few smalll barnacles but not enough (in my estimation) to cause the loss of revs (this has happened to me before quite often when I lived at Miami Beach Marina for 2 years).
So after cleaning the prop I test the boat again and am able to achieve 2800 RPMs without vibration or problem (a bit of additional exhaust smell maybe but I think that was wind direction). This still leaves me uncomfortable since I feel like there should have been more fouling on the prop.
I have in my spares 4 new fuel injectors, guides, fuel line, etc........everything I need to change the injectors; however this is a project I've never done before. I'm normally decisive in this situation but don't really have a direction figured out yet. So, what now ?
1) do nothing......engine has only 2600 hours and things seem OK now. Also, it might not even be the injectors !!!
2) pay a guy to change the injectors and test the engine (hate this option)
3) change the injectors myself (my uncle, the former chief mechanic for a major US city thinks I'm a wimp to even consider paying someone else.........says he could do this in an hour while drinking 3 Buds).
My hesistancy to reflexively go to the "do nothing" option is that if the problem re-emerges in someplace less saturated with potential help I will wish I had dealt with it now.