Maine Sail, what is it about a diesel installation that makes use of a fuel bulb a bad idea? One cracked bulb does not make a case that it is never a good idea, it could have been a faulty bulb and a faulty fuel line is just as possible. I understand my engine makes bleeding possible but the ease of simply squeezing the bulb to push fuel is a lot easier than messing with jumping lines. A squeeze bulb is designed to be used repeatedly with a gasoline engine and is generally outside. I will use mine one to two times a year and will be inside out of weather at all times so very protected. I have read some about this idea including below and am happy with the idea. Idea I saw a few times of replacing it every five years or so is a good idea.
"I have been using Squeeze Bulbs with diesel fuel for well over 20 years now. I still have not seen one rot or fail externally, so to me they have withstood the test of time in the field."
"Nothing I have used does a simpler or better job than the old fashioned and simple "Squeeze Bulb" as to priming the system or using it as a tool to check for other fuel system problems."
"I think the value of this type in installation is 100% obvious to most anybody that has gone through priming a diesel engine in a vessel from both the practical and safety standpoint when you have to get your engine running"
You should understand and be aware that those squeeze bulbs are not rated for in engine room use. I checked with all the fuel bulb makers a few years ago and not one company met the in-engine-room requirements for USCG, Code of Federal Regulations (Federal Law) or the ABYC standards.
If you were to have an engine fire or fuel leak your insurance company may not be very happy. They drop policies over a lot less these days.
Fuel hose is not all the same and in engine room diesel rated hose should be used. The current hose should meet the A1, A1-15 or A2 rating for below deck use.
Granted you'll probably never have an issue, though I have seen it in real life and the rest of the fuel hose was fine. This owner was sucking air and his engine was dying. He lost power in a precarious place which then became a real safety issue. It then began filling his bilge with diesel.
As a member of ABYC I simply called them a few years ago. Here's what they told me.
H-33 (diesel Fuel Systems) requires all hose for engine compartments, even on diesels, to carry an A1, A1-15 or A2 rating not the B1/B2 rating. This means the hose has a 2 1/2 minute fire rating and passes the Code of Federal Regulations testing (CFR) for below deck use. No fuel bulb assemblies meet this Federal Law requirement.
There are currently no bulbs or complete bulb/hose assemblies that meet the A1, A1-15 or A2 fire rating.
So the answer is, to be ABYC compliant (which is to meet Federal Law standards too), this can not be done. Many insurance companies are now reverting to the ABYC standards in the case of a claim and or insurance surveys.
I am in no way suggesting that you remove your bulb, it's your own personal choice, just trying to help you understand the other side of the story and potential pit falls. What you read on the net is not always prudent or "acceptable" to current safety standards. I am sure if they could get these bulbs to meet the standards for engine room or below deck use they would have.
As one who bleeds these exact engines on fairly a regular basis using the test lead method I can do it in seconds thus I feel that on an M3-20B there is little need to insert something below decks into a fuel system that does not meet Federal Law or the ABYC standards.
On your own boat you can do what you want to. All I can do is present the facts as related to the current accepted safety practices and what the CFR calls for. I can also share what I have personally found in the real world of working on boats as I did with the cracked fuel bulb from above...
As I mentioned your engine has the ability to bleed the engine in seconds with a $1.00 test lead. Fuel bulb assemblies run $45.00 - $70.00 these days..
I prefer two hands when bleeding these engines. One to hold the oil absorbing pad under the bleed screw and one to turn the wrench. Can't do that if one hand is priming and the other turning the wrench... Heck an electric lift pump, for boats without one, from NAPA is about the same money than a fuel primer assembly these days...