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My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset


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  #1  
Old 02-26-2017, 11:02:57 PM
JohnnyC JohnnyC is offline
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Default My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

I really did not know how to title this thread, but the title above no matter how you read it fits my problems I encountered today.

It has been MONTHS since I ran my 6.5NH on gasoline. Maybe 8 months. I usually fire it up on propane since it is easier.

Earlier today I fired up the 6.5NH on propane to test a transfer switch. The gas safety solenoid valve nearly caught fire and was burning up. If I had not caught it, the valve may have been compromised by heat, sparks, and possibly fire causing an explosion of highly volatile propane gas. You may have read the story already in the thread below:

https://www.smokstak.com/forum/showthread.php?t=166527

Afterwards I decided to fire up the 6.5NH on gasoline. As mentioned it has been a long time since I ran on gasoline. The 6.5NH fired up, but ran like crap. Gasoline was dumping into the carburetor like me taking a piss after drinking a 6 pack. I was not happy since the carburetor was totally disassembled and completely cleaned out last Spring and ran like a Champ afterwards.

I knew something was wrong and the carburetor needed to be disassembled which I did. For one thing, the gas in the carburetor smelled a little funky, but I was surprised as to what I found at the bottom of the float bowl. There were little black flakes of something in the bowl (both sides) as seen in the first two pictures below. I have absolutely no clue what these black flake are, but without doubt they got into the small passageways in the carburetor plugging them up. For now, I cleaned out the carburetor and blew out all the passages with compressed air. I will reassemble the carburetor tomorrow after I go over it again. The third picture shows a clean float bowl bottom.

I always run a filter inline and the fuel pump has a new filter screen (less than a year old). I checked the line filter since it is see through plastic. It is clean, not a spec of anything. Where did these black flakes come from?

*** Sooooooooo, can I assume my 6.5NH hates me since it failed using 2 different fuel sources?????? Or should we say it is always good to have a backup generator for cases I ran into today? Or maybe both?

JohnnyC
New Jersey
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Last edited by JohnnyC; 02-26-2017 at 11:22:57 PM.
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Old 02-26-2017, 11:26:25 PM
scoops scoops is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

hmm.. fuel line degrading?
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Old 02-26-2017, 11:33:21 PM
oregonfarmboy oregonfarmboy is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

That would be my guess as well scoops. Looks like fuel component breakdown due to ethanol fuel.
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Old 02-26-2017, 11:37:30 PM
JohnnyC JohnnyC is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Quote:
Originally Posted by scoops View Post
hmm.. fuel line degrading?
I was thinking the same, but between the inline fuel filter and the pump there is only about 6 inches of rubber line and the facet fuel pump has a 74 micron screen in the bottom of it. What hat means is either the fuel pump after the screen or the metal fuel line between the pump and carburetor is flaking. The black stuff does not appear to be metallic. Something in th epump degrading???

JohnnyC
New Jersey
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Old 02-26-2017, 11:44:30 PM
Vanman Vanman is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

I've learned that it's best to have zero rubber line After the filter. The rubber sheds those little black carburetor - clogging pieces of $h!t that will have you pulling your hair out!

I hope the source is not internal rubber parts from your fuel pump!
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Old 02-27-2017, 12:12:26 AM
JohnnyC JohnnyC is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

That's why I tried to get the inline filter as close as possible to the fuel pump, regardless the screen filter in the pump should have caught this.

After my last posting I may have an idea where the source of the black flakey crap may have come from..... It may be the float!! The float is made form a black hard-foam material. I am in the house and it is in the garage so I don't have a picture. I wonder if today's ethanol crap gas is attacking the floats on each side of the bowl.........

JohnnyC
New Jersey
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Old 03-05-2017, 09:02:03 PM
JohnnyC JohnnyC is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Since my last posting I completely cleaned the carburetor of the mysterious small black flakes seen in my previous pictures. Upon the initial start up the 6.5NH ran great on gasoline. About 25 minutes into a hard run it started choking again and I seen lots of raw fuel dumping down inside the carburetor. This was 2 days ago... I figured what ever those flakes were, they were back again, but from where? My inline fuel filter was clean. I put the 6.5NH to bed.

Today I decided to further investigate the situation. About 5 minutes into running the 6.5NH it completely died. Upon further investigation I discovered that the fuel pump gave out. It no longer was pumping although it was making the click-click noise when energized.

I removed the fuel pump from the 6.5NH and opened it focusing on its internal filter screen as seen in the picture below. It was clean. No black flakes or anything. At this point I can only assume that the black flakes originated from inside the pump after the internal screen filter and that something internal to the pump broke up and ended up in the carburetor's float bowl. I did not open the carburetor to verify after this latest incident because it was getting late.

JohnnyC
New Jersey
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Old 03-05-2017, 09:46:41 PM
Vanman Vanman is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

So, do you think that the ethanol laced gasoline ruined the pump?
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Old 03-05-2017, 11:43:53 PM
JohnnyC JohnnyC is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Quote:
Originally Posted by Vanman View Post
So, do you think that the ethanol laced gasoline ruined the pump?
I don't know and I don't know where the black flat flakes originally came from or what they were. If I have time tomorrow and energy maybe I will open up the carburetor and 1) see if there are more black flat flakes, 2) save a few to determine what they are made of. It has to be inside the pump or the steel line leading to the carburetor.

JohnnyC
New Jersey
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Old 03-06-2017, 12:46:06 AM
Vanman Vanman is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Might try taking all of the rubber parts out of the dead pump, stick them in a jar with ethanol laced crapoline, and see what happens to them over time...
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Old 03-06-2017, 06:29:21 AM
squidtrap squidtrap is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

JohnnyC- my rubber gasket as you show was falling apart around the edges, also if u pull the middle from the pump apart. plunger and spring and check balls on top you will find a small rubber washer, guess its a check valve also, mine was totally BUSTED causing what u show , and no pumping.

I made one from some thin rubber and it works fine, just my .2 cent. Ed.
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Old 03-06-2017, 08:11:17 AM
Kevin K Kevin K is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

I have had the rubber gasket on top of the plunger degrade and get into the carburetor as well. That's why I recommend a new fuel pump on any generator you are using for a backup. For about $40, it's not worth taking a chance on an old fuel pump failing just when you need it.
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Old 03-06-2017, 12:47:28 PM
geezer88 geezer88 is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Quote:
Originally Posted by JohnnyC View Post
I don't know where the black flat flakes originally came from or what they were.
JohnnyC
New Jersey
Does the carburetor have a black plastic float? If so, is it possible for the float arm to be bent such that the black plastic is rubbing off by vibrating against the fuel bowl?

tom
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Old 03-06-2017, 01:01:15 PM
len k len k is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

3 ideas

1) --- on other small engines I like to replace rubber lines with new, and put an inline filter a few inches before carb. This way any crud in lines/pump/tank that may flake off are trapped in final filter. And flush the new gas lines before closing up carb. I'm done cleaning carbs in cold windy storms.

2) --- May not be the black partials that are causing the gas overflow. On some 70's cars when they started using foam floats they became porous and filled with gas. Throw float in a cup of gas and see if it floats well. Or weigh float then put float in a warm place (130 degs??) to evaporate gas for a week and weight again. After replacement I put the old car foam float in a vice and squished it, gas rained out of it like a wet sponge.

3) --- I just went thru your leaking problem on a Tecumseh carb I rebuilt on a 10 hp snowblower. I assumed float seat was bad and just bought a $4 carb kit with new seat and needle valve. Later I noticed that on the needle the little wire that clipped over float tang was loose on new one and gripped it tight on old one.

Previously I had bent old wire tight to float tang, assuming it would help pull needle out of seat. I guess that may have made it bind. Alternatively could have been an old hard seat , but it didn't seem bad. After installing new seat, needle and, it's wire clip that carb doesn't leak anymore.

Also bore the needle valve went down might have had a tiny speck or 2 of white corrosion on it. I wrapped a good grade of 500 grit sandpaper over a drill and smoothed it out. Up and down strokes so any groove would not grab needle. Used Q-tips in a drill to clean out bottom of bore for seat to seal on.

Last edited by len k; 03-06-2017 at 03:50:37 PM.
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Old 03-06-2017, 07:45:44 PM
JohnnyC JohnnyC is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Thanks for all the comments and suggestions.... Today after work I got busy and did 2 things; 1) open up the carburetor to see what, if anything, is on the bottom of the float bowl, 2) dissect the fuel pump by removing the (for lack of better words) plunger shaft and inspect the rubber components.

1) The carburetor - Keep in mind, I just rebuilt it several days ago by cleaning out all the black crap in the float bowl. This meant disassembling the carburetor, flushing the passages with carburetor cleaner, and blowing everything using compressed air. The carburetor was totally clean and like new.

This evening there was more black crap in the bowls. No way would have I missed the crap while cleaning the carburetor recently. The first 2 pictures attached below show some of the crap found at the bottom of the bowl. There is not as much as before I rebuilt the carburetor, but enough to cause problems. What is this crap???

2) I dissected the fuel pump focusing on its rubber components. Without a doubt, it is shot. Look at the 3rd attached picture below. Those here that are familiar with the pump will easily see the problems, but to make it easy, I marked them out. What remains of the rubber is very brittle.

What puzzles me is some of the crap found at the bottom of the fuel bowl seems too large to fit through the tiny hole in the needle valve seat. Maybe the pressure was enough to force it through?

UPDATE: I found a picture of the same part of the same model pump from my sacrificial 4.0BFA showing the rubber component attached to the end of the plunger (see picture #4 below). It is in very sad condition, but the pump still worked well enough to run the motor.

I will be testing the float which is made of dense hard foam. Stay tunes for the results.

JohnnyC
New Jersey
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Last edited by JohnnyC; 03-06-2017 at 07:59:49 PM.
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Old 03-06-2017, 07:53:13 PM
len k len k is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

When they first started using foam floats in ~ 70's in cars they used wrong material and they became porous to gas and sunk. Later they changed either material or coating and problem went away. Your NH may have been made around that time period.

I suspect gas did not have ethanol or MTBE in the 70's, so it likely was direct attack by the couple dozen components in gasoline. When I tired to use silicone rubber to seal an engine 1/2 gal gas tank it swelled up to 10-20 time it's size to a jelly and just about fell off in ~ 10-15 hours. And I had let a thin coating of that silicone rubber cure for several days before hand.

On my snowblower and generac I add one of these style disk filters inches before carb. They came from O'riellys auto parts and have a fine metal screen, ~ $3. https://www.bing.com/images/search?v...x=3&ajaxhist=0

Last edited by len k; 03-06-2017 at 08:08:23 PM.
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Old 03-06-2017, 08:07:36 PM
squidtrap squidtrap is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Thats it, mine was just like that, totally disintegrated. I made a new one with rubber thicker than an inner tube and all was good. Your pick looks a little different but its on top of the plunger and spring.

missed last pick, its the same, mine has been going 2 years now.

Last edited by squidtrap; 03-06-2017 at 08:09:35 PM. Reason: info
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Old 03-06-2017, 08:08:13 PM
JohnnyC JohnnyC is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Len, I am currently testing the float in my toilet. It is a floater (see pictures below).

JohnnyC
New Jersey
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Old 03-06-2017, 08:10:19 PM
len k len k is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

Not good enough test, test float it in gas.
Gas is only ~70% the density of water, so it may float in water even if float is full of gas.

An empty glass coke bottle floats in water, but sinks in 5 gal pail of gas.
Child hood spent playing with pails of gas from a car at dad's garage.

Last edited by len k; 03-06-2017 at 08:31:37 PM.
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Old 03-06-2017, 08:19:47 PM
Vanman Vanman is offline
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Default Re: My 6.5NH Hates Me -or- It's Always Good To Have A Backup Genset

RTV silicone is readily attacked by gasoline, in fact that's a very effective way of removing it. Two part epoxy (like JB Weld. Hey, you can use it ON a JB!) withstands gasoline, and evidently ethanol laced crapoline as well, as I have a repair on the fuel tank of my truck that is still holding after ~15 years. The nice people I bought it from were too busy talking about their religion and so *forgot* to mention that the tank leaks like a sieve if you fill it up over half way.
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