Perkins 4.236 injector woes?

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Gulfstar 36

Senior Member
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Jul 9, 2012
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234
Location
USA
Vessel Name
Sundowner
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Gulfstar 36 MrkII
As I posed last year my port engine was a little rough to today I pulled the injectors to have them rebuilt next week. They are pictured left to right front of engine to back. 3 Issues I saw right away. 1. #2 and #4 have no washers. I think they might be stuck to the head. 2. #1 and #3 have 2 washes?? 3. #4 looks like it was not firing correctly at all looking at how oily it is.

How do I get the washers out of the hole? Is there supposed to be 2 washers on a Perkins 4.236?
 

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Some Perkins experience here. They all look very tough but you can't tell much by looking about how they are injecting.
One (and only one) washer each is correct.
By all means have them rebuilt.
You should be able to hook the washers out with a curved pick, just be sure you get a good quality one from your tool seller; you can't have anything snap off and go in the cyl.
Clean the bores in the head, and install the rebuilt injectors dry without anything that will interfere with heat transfer.
 
Thanks! I was hoping there would be some overhang to get a hook in there. I can tell but I bet these have been there some time. They took some effort and a rubber mallet to get out. This is a 38 year old engine.

Some Perkins experience here. They all look very tough but you can't tell much by looking about how they are injecting.
One (and only one) washer each is correct.
By all means have them rebuilt.
You should be able to hook the washers out with a curved pick, just be sure you get a good quality one from your tool seller; you can't have anything snap off and go in the cyl.
Clean the bores in the head, and install the rebuilt injectors dry without anything that will interfere with heat transfer.
 
At a guess I suspect the rust is the result of "cold fuel" versus "hot engine"= condensation, the number 4 looks the worst, I'm surprised it ran at all!!.
 
This engire was winterized last November after clocking 85 hours last year. I started it up this past weekend, ran it up to 140f , changed the oil and removed the injectors.

Did the engine sit unused for a long period?
 
Hope the curved pick works, I've not had 100% success using a pick. What has always worked is a 4-236 head bolt. It will screw into the washer hole, allowing you to remove even the most carbon encrused washer. Not sure of the size, think it is 5/16th or 3/8th, take a washer to the hardware store and find a bolt that will screw into the hole.
 
I only have one that I could not get out so I gave it a quick shot of PB Blaster. I'll give it another try tomorrow.
 
For my education, could someone explain why the injector barrels appear to be somewhat rusty.

Not unusual. The barrel is not really "in" tne engine, it goes down a " slip fit" bore in the head which gives several sq. inches of contact area to carry heat away from the injector and to the coolant. Really, only the nozzle and interior parts need to be perfect.
 
This was the ticket but I just used a tap:thumb:

Thanks again.

Hope the curved pick works, I've not had 100% success using a pick. What has always worked is a 4-236 head bolt. It will screw into the washer hole, allowing you to remove even the most carbon encrused washer. Not sure of the size, think it is 5/16th or 3/8th, take a washer to the hardware store and find a bolt that will screw into the hole.
 

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I installed the rebuilt injectors on Sunday. I cleaned out the head the best I could and used a shop vac with a piece of 3/8 fuel hose to remove any bits that remained. I gave them a coating of never seize and dropped them in. Once started the engine idled much more smoothly and in gear at 1000 RPM the vibration I noticed before was diminished. Also the previously noted sheen on the water was gone. I’ll know for sure when we get out in a few weeks and can run it up to 2000.
 
I had the same issue with a washer that was stuck. I had injectors rebuilt on both Perkins engines. I didn't want to damage the old existing washer so after attempting with a pick, I decided to leave it in. It is causing no problems and both engines run smooth now with no smoke. Injector rebuild company owner in Portland suggested adding 1/4 of a quart of tranny fluid to each 100 gallon tank for injector lubrication.
 
You might contemplate a new crank vibration damper , if the engine is fitted with one, 38 years is a long time for rubber parts in a bilge.
 
Injector rebuild company owner in Portland suggested adding 1/4 of a quart of tranny fluid to each 100 gallon tank for injector lubrication.

Not surprising, the guy makes money by selling injector parts.

But for what it's worth, the amount he suggested isn't going to make nuch difference one way or another in an older design engine. Find another source of operating advice.
 
Many antique injectors expected the lubricants in old high sulfur diesel to be there.

Sulfur was a lubricant , that is now gone.

A quart of ATF is really cheap insurance considering its cost.

Some folks use 2 stroke outboard oil in the diesel fuel instead .

Most folks don't use there engines enough to find out service life changes ,

but the few bucks required over the next 40 years is minor.
 
Many antique injectors expected the lubricants in old high sulfur diesel to be there.

Sulfur was a lubricant , that is now gone.


The sulfur myth is harder to bust than a crooked politician.

The Earth is not flat, the government is not at your door to help you, and sulfur is not a lubricant. It never was.

All diesel fuel on the market today meets the lubricity standards required for any diesel engine. Period.
 
Your harsh Rick. The man that rebuilt the injectors has been in business for 35 years and is a dear friend and did the rebuild for no labor. 2 cycle oil will add sulphur back to fuel. I agree withany others. Adding 2 stroke oil won't hurt and will likely help.
 
Your harsh Rick. The man that rebuilt the injectors has been in business for 35 years and is a dear friend and did the rebuild for no labor. 2 cycle oil will add sulphur back to fuel. I agree withany others. Adding 2 stroke oil won't hurt and will likely help.


I am not harsh, facts are facts regardless of how they make someone feel or how long they have been doing something.

And just for the record, you didn't say anything about 2-stroke oil, you said ATF, which is popular with the less informed because they believe the high (in the thousands of ppm) sulfur content of the stuff will magically transform ULSD into a kind of injection system lubricant. FF mentioned 2-stroke oil as the magic sauce of choice for those who need to believe their fuel is too risky to use as is.

If you believe sulfur is a lubricant or even more ridiculuous, a lubricity enhancer, you have missed a couple decades of fuel and lubricant analysis, evaluation, and resulting literature. That fantasy belongs with the flat earth crowd.

If you can find a 2-stoke oil that contains less than 15ppm sulfur let me know. Last time I looked at the stuff it had about 50 times the limit for diesel fuel. Using any additive that increases the sulfur content of fuel is illegal in any event, therefore adding a faith-based elixir is more than just stupid and pointless, it's expensive.
 
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If you know a dentist get some dental pics good strong stainless they won't break on you.

I use them for packing material in the stuffing box and all sort of things.

Handy.

SD
 
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