Need help understanding MD7A fuel lines

[esarratt]

Originally Posted by Shawn67

" when I was fixing a bent water muffler exhaust intake. Volvo said the part was not available and if it was...$100. I took it to a machine shop and they bent it back in place for $10."

Is that on the water injection point? On my Sabre they didn't use the Volvo part for that. They made a riser out of black pipe. I replaced that when I was converting to fresh water cooling. The flange on the exhaust manifold is just 1.25" NPT.

No it is not; it is the water injection point for the muffler itself. Here is a pic to clarify.

[esarratt]

Originally Posted by Shawn67

If you are removing the exhaust manifold you are going to need cooling system gaskets. West Marine sells them cheaper than Volvo. Order part #10511004. I know they say it is for stern drives but it is the proper set for the MD7A. That has the thermostat gasket, the O ring in the thermostat housing as well as the square ring push on gaskets for the thermostat housing, exhaust manifold inlet the two at the water pump and the gasket for the connection to the transmission.

Sounds like you have a nice alternator setup. I will have to keep that in mind if mine ever dies.

Shawn

Thanks for the information on the piping and the gaskets. Everything helps.

When I get back to the boat I will take pictures of the alternator setup and provide the exact model number.

[esarratt]

Originally Posted by Wotname

I just came across this link about small marine diesel fuel systems and thought you may be interested. Try to ignore the Yanmar reference

FUEL SYSTEM INSTALLATION

Nice. Thanks.

[Shawn67]

" I cut off the retainer (with a Dremel cut off wheel) and made that a normal hose clamp fitting."

So it is basically a hose barb inside? Nice tip, thanks! I will likely need to use that when I put in a different fuel filter before the lift pump.

Thanks for the compliments on the engine. I bought the boat last year and the day I took delivery the engine died in my harbor after motoring flawlessly for about 7 hours. Local mechanic didn’t want to touch it. I couldn’t afford to replace it so I went through a crash course in diesels. Got it running 5 weeks later (high pressure fuel pump had died) and then had overheating and sporadic issues with #2 not firing. After loads of work the engine is finally getting to the point where I can trust it. I like its stone age simplicity.

Shawn

[esarratt]

Originally Posted by hpeer

While you have the exhaust manifold off look at the fuel return FITTING. on my MD7A it had an origional fitting where the hose could not be changed without removing the exhaust manifold.

Ok. You bring up an interesting point and I need some information from you on this.

Were you ever able to remove the fuel return fitting with an open end wrench WITHOUT removing the exhaust manifold? I just removed all my fuel lines today to replace them except this one.

Originally Posted by hpeer

There is a banjo fitting and a crimped retainer. I cut off the retainer (with a Dremel cut off wheel) and made that a normal hose clamp fitting. If the hose goes I can easily replace it.

Same goes for the hose to the lift pump.

So....how long are the "barbs" on the banjo fittings? I just tried to find the fuel return line and Volvo doesn't make it anymore. The other two lines are $120 and $177. UGH!

I would prefer to replace the fuel lines since they are 30+ years old--with that groovy fire resistant hose, before recommissioning.

Monday I am going to go to a hydraulic shop and a diesel shop to see if they have a similar fittings. NAPA was a bust for this.

I am also considering Dremeling off the crimp fitting like you, but I want a good connection (at least 1 clamp). I too am of the mindset that a clamped fuel line is easier to fix in the future than a crimp.

Did you actually remove the crimping for all the fuel lines?

Anyone else feel free chime in.

Thanks!

[hpeer]

Well, to be precise, the FIRST time I did this I took the banjo to my hydraulic shop to get a new one. THEY cut it off and gave it back to me. The second time I used a Dremel.

I had plenty of room for a clamp connection.

[esarratt]

Thanks!

[wearde]

Originally Posted by esarratt

I searched the forums for good detailed pics about this and found nothing. Thanks for the help in advance.

What I am really looking for is a little advice and a few pictures of good MD7A fuel line setups.

Here are some pics of my morass.

The two l-o-n-g fuel lines from the left and right side of the engine both go up to the fuel tank to a T connector (that attaches to the tank).

I realize that the left line is for leftover un-burned fuel, but why this type of setup? Two lines like this seem awfully long.

I have the owners and workshop manuals, but they are not specific on these points.

Suggestions besides "throw it away" would be welcomed.

Note, my to do list already includes: moving the battery negative, replacing the rusty fuel line, cleaning and testing the sensor, and painting the engine.

Hi Esarratt,in one of the posts about the MD7 fuel lines you mentioned having a SEV Marchal alternator 70 229172 spare, in 2015. Is this still the case?


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Colin (Wearde)