Injector Size

[dottieshusband]

How do you tell what size injector you have. The engine is a 650hp 12v71Ti in a 1987 63 Hatteras. Would like to carry some spare injectors, but Diesel Pro had about half a dozen nozzel sizes. Help is appreciated. Thanks

 

[Boatsb]

What will you do with the spare injectors? Can you diagnose and replace it yourself?

 

[Pete]

Let me disagree on the need to carry spares. There are a set of rules that come with every boat that are undeniable truths:

Boat engines only require unplanned service the day before or on holiday weekends.

Boat engines only require unplanned service went at least 50 miles away from a parts location that has the parts you need, and they are closing in the next half hour.

Having a part onboard almost guarantees you will never need it. And if you know how to replace the part and set it up, that guarantee goes to 100%.

Thus I recommend carrying all the hard to replace engine parts, learn how to install them if possible, and enjoy cruising.

But, just in case, if you do have a problem, a Detroit mechanic is usually available anytime for a price, and being able to say to him, OH I HAVE ONE OF THEM, can be a great stress reliever.

And as far as what injectors your engines have, you must pull a rocker arm cover and look at what identification is on the injectors. Any thing less is a waste of time.

Pete

 

[Genesis]

Yep on the method.

There is a small plate on the side of each injector with a number. Remove a rocker cover and look, then get one or two of those.

I entirely agree with "if you don't have one it will break, and if you do have one (or two) you will never use it." I've found that Murphy lives on boats and he's a bastard.

 

[MikeP]

Totally agree - the only thing that might be a consideration re the actual injector in the engine is whether a PO may have made a change for either more power or more economy and not told the buyer/logged it in the logbook. So it's possible that the injectors eng in the engine might be different than what was originally installed.

The engine tag should be on one of the valve covers or, if not (hopefully) in the boat's manual/other paperwork and it will show what was in the motor originally. The eng tag shows all sorts of info, including oem thermostats, etc. Folks like Atlantic Detroit Diesel-Allison may be able to come up with the same info if they're given an engine serial number. They did that for us on Long Island on several occasions.

 

[Glory]

Let me disagree on the need to carry spares. There are a set of rules that come with every boat that are undeniable truths:

Boat engines only require unplanned service the day before or on holiday weekends.

Boat engines only require unplanned service went at least 50 miles away from a parts location that has the parts you need, and they are closing in the next half hour.

Having a part onboard almost guarantees you will never need it. And if you know how to replace the part and set it up, that guarantee goes to 100%.

Thus I recommend carrying all the hard to replace engine parts, learn how to install them if possible, and enjoy cruising.

But, just in case, if you do have a problem, a Detroit mechanic is usually available anytime for a price, and being able to say to him, OH I HAVE ONE OF THEM, can be a great stress reliever.

And as far as what injectors your engines have, you must pull a rocker arm cover and look at what identification is on the injectors. Any thing less is a waste of time.

Pete

For Pete's sake, that is all so true.

JM

 

[captddis]

injectors are N90 for the 650HP 12V71.

 

[luckydave215]

Murphy was an optimist......

 

[davidwigler]

I read recently I believe on this site, that new injectors are often defective and rebuilding ours when necessary is recommended.