# Honda EU3000is Surges, only runs choke pulled mostly out, Carb Repair Help?



## xyobgyn

I have an old EU3000is.

I tried to start it this weekend, in anticipation of winter, and possible use. It barely started, and really only liked choke pulled all the way out. I had to run the choke back and forth a bit to keep it running at all. To me, it seemed like a clogged up carb.

I'm handy, but not experienced.

I took the carb out, and was horrified how clogged up the main jet and nozzle were (parts 11,28)
I cleaned out the pilot jet (parts 29) New O ring for that.
New O ring for bowl, as well as the drain screw. 

I cleaned off a ton of varnish and debris from the float and bowl. 

I was not sure how to get part #5 out, also labeled a pilot screw, but I went back and forth on it, and sprayed a ton of brake cleaner through the area where it enters the carb. I was careful to open up all the passages I could see into the carb, including some really tiny ones in the wall.

I put on a new fuel hose, as that was brittle.
I put in a fresh plug, the old one looked fine. I drained all the oil, and put in fresh 10W-30 Mobil One.

I got new gaskets, the only issue there I ran into, I can not really explain, but don't think its the problem. Upon reassembly, the thick metal gasket spacer with rubber coating spaced the choke plate to far away, so there was binding, and the choke would not move. I doubled up a pair of paper gaskets in that spot, and that relieved the choke movement. No passages blocked there.

I bought a small quantity of ethanol free gas from Menards, just to start it up, and store it. The tank was completely empty of the old gas.

It STILL only runs well with choke pulled out all the way.

There seems to be a strainer in the bottom of the tank. Leads right to the valve on/off for fuel.

When I shut off the fuel, and let it run dry, there is still some gas in the bowl when I open the drain screw to the line, and drain it.

Is it possible the flow is THAT bad through the intake strainer? Does that item function like a fuel filter that I should swap it out?

(I guess I could test this by bypassing the fuel tank, with a longer hose, and just feed off a funnel and nipple to the carb direct.... )

There is no conventional inline fuel filter as I've seen on other small engines.

I'm comfortable taking it all apart again, and looking at the carb after running it, I suppose some debris may have gotten into it, but it really doesn't seem to run THAT much better than before the cleaning, despite the horrific amount of varnish and plugged holes in the carb.

Looking for suggestions, other than bypass the fuel tank, and go direct. I'll give that a try, and report back... 

I bought a fair amount of parts for this, including a nice carb cleaning kit with probes/cleaners of all sizes. I'm not against buying a whole fresh carb, but it seems a shame at this point.

Not sure how I would test to be certain that the electronic throttle is functioning right. I read of one situation where someone pinched wires on that harness and lost function. I guess I could take a meter to the plug and try to check continuity, but it seems unlikely, I was pretty careful. 

Open to suggestions.... thanks in advance.


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## xyobgyn

Well, I answered my own question. 

Ran a foot or two of fuel line off a funnel hanging over the engine, direct to the carb. Runs perfectly.

The “screen” as Honda calls the part poking up into the bottom of the tank, directly attached to fuel manual valve, must be plugged badly..

I wish there was a more obvious inline fuel filter, I would have seen and replaced it preventatively. But at least I didn’t just buy a new carb, only to find that wasn’t the problem after all. 

How many times do we have to repeat the mantra? Fuel, Air, Spark.


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## xyobgyn

*Honda Parts*

Well, 

The fuel valve does incorporate a small filter in it, and there is a pencil like tall screen/filter that protrudes into the tank.

All these parts were junked up on mine. I tried to delicately remove the assembly, but it crumpled, and the o-rings were all toast.

The added up cost for new O-rings and filters was about the same as a whole new assembly complete, and frankly, it was hard to clean out the valve nicely.

So.... I bit the bullet and bought a new assembly. Give credit where due, the Generators as built and let out from the factory are very reliable. So, I'll restore this to factory configuration.

I think the cheaper way to fix this would be take it apart as I did, remove the tall thin inner tank filter, remove the small round filter in the valve, just tear out the filter section. Put in new O-rings, and install a short aftermarket fuel filter in the line between the tank and carb. There is room, and then service would be easier. If there is a next time, I'll do that rather than paying the price of new parts.... I'll splurge once as this is still a reasonable price to pay for DIY, as well as a bit of a sting to take better care in the future.


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## Predator

So did that get it running properly?
I have a nagging feeling you're going to end up needed a new carb. You'll be VERY lucky if you don't.



Carbs tend to disintegrate from the corrosives left behind when gasoline absorbs water from the air.
Turns them to aluminum oxide powder.


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## xyobgyn

Predator,

Well, I have mixed results, and I ran out of time last night, and had no time today to sort it out completely.

My memory from last weekend is that when I hung a gravity fed fuel source direct to the carb, bypassing the EU3000 tank, filters, fuel valve etc... that the generator ran beautifully, distinctly differently than when fed by gravity from the fuel tank as it should be. Hope to have linked a photo from FB. Not sure if that violates policies.

Now I wonder if I'm losing my mind. (Wouldn't be the first time. While I'm board certified in delivering babies and gyn issues, small gas engines are not my area of expertise.)

I put in a brand new fuel valve, with its built in fuel filter, and a new in tank screen that all comes together in a single parts bag from Honda. You can buy the individual parts (filter, valve, O rings, strainer) separately too.

Im still having some fuel starvation issues, but to be sure, (in retrospect) I poured in very, very little of the ethanol free gas in my test, it may not have been enough to run smoothly.

At the cost of the ethanol free gas at Menards/Home Depot, I'm sorely tempted to follow the DIY route, and make my own. This weekend, I'll fill the tank more fully, and see if I can finally run with the choke in as it should be. I did take off the spark arrestor, and it wasn't bad, just on the off hand chance it was a contributing factor.... Its about all thats left to adjust aside from valve clearance, and inspecting for carbon build up with a scope. 

Incidentally, there is a 5 amp fuse for the starter on the side of the genset once the front cover is off. Mine was blown, which was sweet to find as a fresh battery to replace the one that wouldn't take a charge didn't solve the problem until I checked that fuse.


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## Melson

I have the same unit, wasn't aware of the extra screen filter in the shutoff valve. Thanks for that heads-up.
While both my previous eu2200 and this eu3000is have been totally reliable I have found that Honda, in its due diligence mindset, can over-engineer and/or produce parts with such a high degree of fine tolerance that, conversely, there's a low tolerance for user neglect or lack of maintenance. The fuel system seems a prime offender.
For example, the main jet in the carb of the 2200 genset is such small diameter that I discovered no amount of gas treatment would stop it from clogging if I left unused for as little as one month. Not kidding.
I have learned to shut the fuel valve off and then run these Hondas until out of gas, which has worked for to keep the carbs ready for use after months of inactivity.
I know this doesn't help your issue one bit. I do hope you continue to post here your continuing saga.


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## Dutchy491

I also have the newest Honda 2200 Inverter and I like that it has the ability for me to turn the fuel off so that I can run the unit until the carb is empty. Unlike the older 2000 units that you had to manually drain the carb. That being said, I have used AMSOIL Quickshot for years in all my small engines including my Yamaha ATV and Harleys and I like it alot. It seems to keep my stuff running great and provides a bit of stabilizer as well. According to AMSOIL about 6 months I think. _ focuses on three major fuel-related issues plaguing these applications: ethanol, water and dirty pump gas_ Here's a link. https://www.amsoil.com/shop/by-product/fuel-additives/gasoline/quickshot/?code=AQSCN-EA/?zo=331384 I can't find it locally so I usually order online and I get it in a couple of days. Works for me. Dutchy


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## kipsy

I have a five-year-old EB 4000 Honda generator, this fall it has surged. I started yesterday and needed choke to start, the auto choke wasn’t helping. I found that if I remove the air filter it would no longer surge or very little if any. I did connect a circular saw to test And found that it did not consistently stay at the same RPM and could tell that the saw speed was changing a very little not sure if this is normal.Can anyone give me any advice as to what to check next


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## sportplumber

This study is interesting as most of the products like Stabil don't seem to work. Amsoil not in there and a fine company but download the full report to see the results.

https://cropwatch.unl.edu/ethanol-and-water-contamination-—-comparing-water-removal-additives

University of Nebraska


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## Melson

Some of my work responsibility was field support on power equipment for Verizon. Mostly that would be turbine and diesel gensets, but also some smaller gasoline units.
Our experience was that fuel stabilizers either didn't work or, well, I'll just say that basically they didn't do as advertised. Believe me, we would have promoted those products if they had. 
I know this will be blasphemy to many, and maybe that stuff does help slow things down a bit. Maybe. But I can't even think of how many Onan carbs I rebuilt. Thank goodness, around 1990 we got funding to transition those smaller C. O.'s to Vertipac diesels. Which were - oh, brother! - horrible, but not because of bad fuel.
I guess my feelings are that if you think stabile et all, work then you must be doing something right.


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## Dutchy491

https://www.amsoil.com/lit/databulletins/g2761.pdf


Above is a link to the Data sheet for AMSOIL Quickshot. The fuel from today can contain Ethanol where in 1990 that wasn't a concern. The test data from the University of Nebraska is interesting. Too bad it didn't include AMSOIL or several other common brands. Dutchy


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## HarryN

Your experience is very similar to what I have experienced with honda lawnmowers with modern gasoline.

Modern gasoline, especially in areas with oxygenate additives (example CA) is not nearly as stable as gasoline sold in other areas. The oxygenates help slightly reduced exhaust pollutants in fuel injected engines, so they are widely mandated use. What they don't tell you is that within 30 days, they start to polymerize and at 90 days, they are polymerizing substantially.

In my honda mower, the symptoms were very similar. I was doing the same adjustments.

I was rebuilding the carb 1 - 2 x per year. Sometimes I would do it, sometimes I paid to have it done. (keep in mind we mow the yard 8 months a year here) The reason that professional mower companies don't usually see the problem, is that they go through many gallons per week in a mower. My yard is small, so that little tank would last 2 - 4 weeks.

I tried every fuel stabilizer out there and even used more than is suggested multiple times. None of them work on this situation.

I suspect that there is an alloy in the honda fuel system that actually catalyzes this reaction, but it doesn't matter.

Eventually I listened to the lawn mower shop and out of desperation, bought one of those "cans" of gasoline that doesn't have oxygenates in it. The problem disappeared and now that is all I use in that mower. I have not had to do anything to that mower since, other than an oil change.

After that, I also switched out the fuel (2 cycle) in my chain saw.

Home depot and lowes sell these canned fuels locally now, so the price is less - still a lot more than a gas station, but overall still cheaper for me than rebuilds on that mower.

The odds of canned fuel solving your problem, IMHO, are high. Probably you won't like putting $15/ gallon gasoline in a generator, but sometimes there aren't many options.

This is frankly why I bought the solar generator setup for my garage fridge. There just isn't any way to store viable amounts gasoline for a power outage.


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## Dutchy491

Harry, canned fuel simply isn't an option for generators or many other small engines for that matter. Way way way too expensive. Although it works if money isn't an option. Have you ever looked closely at the carb on your Honda mower to check if there is a fuel drain? All my Honda engines have some sort of drain and I religiously drain the carb after use (close the fuel spigot and run the engine until it stalls out then drain) unless I plan to use that particular piece of equipment again in the next day or two. Every time I drain a carb there is usually one to two tablespoons of fuel that dribbles out. That is the cause of many carb issues, especially if ethanol fuel is used. My solution is to buy ethanol free high octane fuel, but first put $5 in my truck before filling my jerry can, to flush out the fuel grade that the previous customer bought. If you pull in after a biker they usually use Super in their bikes so the pump is already purged. I put the appropriate amount of AMSOIL Quickshot in the jerry can prior to filling with fuel so that it is all properly mixed. At the beginning of the month I pour the remainder of that can into my truck and refill the jerry can with fresh gas and Quickshot etc. This has worked for me for years. Find AMSOIL Quickshot and use it like I have, as stated above, and get back to us. It is important to be diligent or you will get bit! Harry and others have been there and me too, and never again if I can help it!! Dutchy


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## HarryN

Dutchy491 said:


> Harry, canned fuel simply isn't an option for generators or many other small engines for that matter. Way way way too expensive. Although it works if money isn't an option. Have you ever looked closely at the carb on your Honda mower to check if there is a fuel drain? All my Honda engines have some sort of drain and I religiously drain the carb after use (close the fuel spigot and run the engine until it stalls out then drain) unless I plan to use that particular piece of equipment again in the next day or two. Every time I drain a carb there is usually one to two tablespoons of fuel that dribbles out. That is the cause of many carb issues, especially if ethanol fuel is used. My solution is to buy ethanol free high octane fuel, but first put $5 in my truck before filling my jerry can, to flush out the fuel grade that the previous customer bought. If you pull in after a biker they usually use Super in their bikes so the pump is already purged. I put the appropriate amount of AMSOIL Quickshot in the jerry can prior to filling with fuel so that it is all properly mixed. At the beginning of the month I pour the remainder of that can into my truck and refill the jerry can with fresh gas and Quickshot etc. This has worked for me for years. Find AMSOIL Quickshot and use it like I have, as stated above, and get back to us. It is important to be diligent or you will get bit! Harry and others have been there and me too, and never again if I can help it!! Dutchy


I agree with you.

At the time of my fuel / mower challenges, ethanol was not common in CA gasoline. They used a different oxygenate, but I don't know what it is.

In some seasons, we are mowing the yard 2x per week - it is just a really small yard. Occasionally my son mows the yard, and randomly my wife will if I am on a business trip. Neither will drain the carb so the fuel system has to be able to work on its own.

I only ever use "super" / high octane gasoline, so that isn't a factor. I even went to some bother to use a specialty race car fuel station to buy gasoline.

I just gave up on generators except for really rare situations and bought one of these 1x3s. Essentially it uses solar most of the time to run the garage fridge and uses the grid as needed if for some reason the sun cannot keep up. The fridge is all I really care about, but it can run other stuff as well.

https://wirlnet-inc.square.site

If I could purchase gasoline that was reasonably stable, I would go the generator route, but that just isn't reality in California.

I didn't try the amsoil product that you suggested. I probably won't because I am not willing to risk another $120 mower repair bill vs just buying some canned gas. It might make sense for others though.


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## HarryN

Dutchy491 said:


> https://www.amsoil.com/lit/databulletins/g2761.pdf
> 
> 
> Above is a link to the Data sheet for AMSOIL Quickshot. The fuel from today can contain Ethanol where in 1990 that wasn't a concern. The test data from the University of Nebraska is interesting. Too bad it didn't include AMSOIL or several other common brands. Dutchy


I was actually using 10% ethanol fuel in 1979 in IA in a car with a dodge slant 6. It worked just fine back then and I have no issue using it. The 2000 dodge mini van I have is actually rated for using up to E85. It is a bit weak on torque, but keeps going, so I drive it.

My suspicion is that the honda small engines have a part made from a copper alloy and that this is at least part of the problem. Copper alloys are well known for causing fuel system problems and reactions. That is a guess on my part, but the way the fuel polymerizes is what you would expect from this kind of issue.

EDIT

I thought about this some more. Perhaps there could have been problems with polymerization with 10% ethanol fuel, but I used about 2 - 4 tanks per month, so would not have really observed it.


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