Honda GX270 +23 year old carb: Rebuild or Replace?

[FTG-05]

I have a NorthStar 5500w generator with a Honda GX270 engine (GCAB-VNT2, serial number 143xxxx. The genset was bought summer 1999 and was last run late April/early May 2011.

I got it restarted a couple days ago; ran fine for about an hour on and off while I was using it to drive fence posts. I went to refuel it and when I tried to start it, the engine hydrolocked. Removed the spark plug, pulled the cords, tons of fuel came out of the spark plug hole. Reinstalled the spark plug, no spark, nothing.

I can get a carb rebuild kit off of Amazon for about $20 or a brand new carb replacement for about $16. Obviously, the new carb is China-made; Honda OEM carbs go for $90-$175.

If I rebuild it - which I've never done before - I risk a) losing some part and/or b) not reassembling it correctly. Plus, it's a +23 year old carb, that's been neglected for over 12 years, there is bound to be other parts not included in the rebuild kit that will need replacing, like gaskets.

Which do you recommend?

Thanks,

 

[GMB74]

The problem with your current carb is the inlet needle and seat not sealing properly and/or the float sinking and not closing the needle.
Have you taken the carb apart? At least pull off the bowl and see what it looks like in there.
If it is really gunked up or corroded, the carb is probably junk.
If not too bad, you may get away with a good cleaning, a gasket set and needle/seat. Check the pricing on these items to see what you are getting into. These carbs are pretty simple to work on, but have really small jets and passages that are easily clogged up and damaged by old gas, especially ethanol gas. A new carb might be a better option.
I have had mixed results with the Chinese carbs. Sometimes they work, sometimes they don't. You get to do the final quality control check (which they don't do at the factory) when you buy one. If you go that route, check the seller's return policy carefully. If you get a bad one you have to choose whether to try and send it back for a refund or just trash it and buy another one to try.

 

[FTG-05]

I'm going to take the OEM carb off today and see what I see. I'll post pics when I do.

Thanks!

 

[legdelimber]

I don't have any experience with Honda powered equipment,
But "back in the day" their keihin carburetors on their motorcycles were bad to get "chalky" deposits inside (plus gummy from sitting with old fuel) that cloged the small passages and the pilot/idle jets.

Was a time consuming pain finding tiny wires or torch tip cleaners to gently clean the crud out.
Plus cans of carb cleaner that wanted to splatter back in your face, so be cautious with them and wear some safety glasses when using them.

Drove my friends nuts with idle/low speed problems on the bikes, until finally they gave in and cleaned things proper.
I'd be very tempted to buy the replacement carb, but doing exactly as GMB74 wisely says about the return policies!

 

[chipper1]

I've cleaned hundreds(literally) of honda carbs, very few times I've spent money on a rebuilt kit, and even fewer on a new carb.
You'll spend less time trying than you spent making this thread and ordering a new carb would take. If it doesn't work then order a new one.

 

[stretch5881]

I just worked on the same gen last week for the 3rd time. Water in the gas. The 3rd time, I could not get the carb to work right. It had a rumble that was likely lean running. I got the carb from amazon and it runs smooth. Now he has to check his fuel source.

 

[FTG-05]

I've cleaned hundreds(literally) of honda carbs, very few times I've spent money on a rebuilt kit, and even fewer on a new carb.
You'll spend less time trying than you spent making this thread and orderinga new carb would take. If it doesn't work then order a new one.

What action am I supposed to take with this advice?

 

[FTG-05]

Pics:











I'm certainly not trying to pretend to be an expert here - but that carb looks pretty dang good to me for being +23 years old and being neglected for the last 12 years.

What do you think?


ETA: Why do my pics show up when I add them or when editing, but show up as crosses when I read the thread? Is anyone seeing the above pics? Help!

ETA@: Dragged them direct from my PC; let's see if that works. Some forums are rejecting Imjur pics for some reason (e.g. GJ).

 

[chipper1]

What action am I supposed to take with this advice?

Clean the carb.

Pics:

I'm certainly not trying to pretend to be an expert here - but that carb looks pretty dang good to me for being +23 years old and being neglected for the last 12 years.

What do you think?


ETA: Why do my pics show up when I add them or when editing, but show up as crosses when I read the thread? Is anyone seeing the above pics? Help!

Not sure what's up with the pictures not showing up, as soon as I quoted it I could see them .
Carb looks great to me. It probably had a small piece of debris that got caught under the float "needle"(the black part in the pictures).

Inside the threaded hole below is the nozzle, it's a small brass piece that has a bunch of very small holes in it. To remove it if it doesn't just fall out, I reach into the bore of the carb(where the air comes in) and push it up a bit with a screwdriver, sometimes it will take a couple tries. Then I spray into the end of it with a can of brake parts cleaner to see if any of the small holes are plugged. If there are holes that are plugged I use a small torch(crack pipe ) to burn the resin, whoops I mean debris out, then I use the brake parts cleaner on it again to make sure all the holes are clear.

Also under this cap may be a filter, or just a "drop loop" of sorts, it catches a lot of debris that would go straight into the carb as it's right where the fuel enters the carb.
Remove the cap and see what's in there, and then clean it out and see if you can get a filter for it if there isn't an inline filter in the fuel line
, if there is that filter may need to be replaced.

If you could snap a picture of the bolt that holds the float bowl in place, that would be useful too.

Hope this helps. If you need more detail than what can be put into a quick post here, send me a PM and I'll get you my number and walk you thru it. But these are the main areas I hit and or should take care of what you described the problem being.

 

[chipper1]

I just worked on the same gen last week for the 3rd time. Water in the gas. The 3rd time, I could not get the carb to work right. It had a rumble that was likely lean running. I got the carb from amazon and it runs smooth. Now he has to check his fuel source.

Ethanol fuel will suck the water out of the air and then separate. I don't let any small engines sit for longer than a couple months without running them, and I keep the tanks full. The only one I have problems with is my pressure washer, kinda hard to run them in the basement without water hooked to them. I run them dry, then add some ethanol free fuel to the tank, and run them a bit and I don't worry about them until spring/summer.

 

[stretch5881]

Ethanol fuel will suck the water out of the air and then separate. I don't let any small engines sit for longer than a couple months without running them, and I keep the tanks full. The only one I have problems with is my pressure washer, kinda hard to run them in the basement without water hooked to them. I run them dry, then add some ethanol free fuel to the tank, and run them a bit and I don't worry about them until spring/summer.

The guy I fixed it for uses non-ethanol fuel. The generator hadn't been run in 3 years. I cleaned the carb, put some fresh gas in it and it ran good. He used it for a weekend building a new tree stand in the woods and said it started to run goofy. Then he could not get it started. I found about a cup of water after draining the carb and tank. The fuel filter had enough water in it that it would not let the gas flow past it. I cleaned the carb again in a heated usc. Got the gen started and the rumble wouldn't clear up. The rumble is a weird flame in the cylinder.
A cheap amazon carb and fresh fuel, it runs like new.
So a 20 dollar carb, a 2 dollar filter and 10 minutes to change them wasn't the worst idea.

 

[FTG-05]

Took it apart some more (main jet, main nozzle and the fuel strainer cup ie. those mentioned by Chipper) and then soaked them in Chem-Dip carb cleaner for 30 minutes. I haven't uploaded the pics yet, but I'll post them once I do.

Thanks for the help!!!

 

[GMB74]

That carb looks remarkably clean for its age.
Chipper1 has covered things quite well.
I agree with him, a little bit of debris may have caused the inlet needle not to seat and cause your problem.
Cleaning should remove that.
I think you are on the road to recovery.

 

[FTG-05]

I'm ready to put it back together. However the Main Nozzle fell out without me seeing which direction it went in.

Here's the part, this is the pre-soak pic:




Which end goes in first and which end goes against the Main Jet. Here is the diagram I'm using as a reference:

PartsTree - Home of OEM Parts for Outdoor Power Equipment

Parts lookup and repair parts diagrams for outdoor equipment like Toro mowers, Cub Cadet tractors, Husqvarna chainsaws, Echo trimmers, Briggs engines, etc.

www.partstree.com

The Main Nozzle is part/item #13; the Main Jet is part/item#28 in the diagram linked above.

thanks!

 

[legdelimber]

Fuel stains and smaller (fuel) holes, typically at the bottom, in the fuel bowl. Usually the larger (side/cross holes) are closer to the top.
Can you look up into the hole where it came from and see any marks that match the nozzle/mixing tube?
Also look for any threads that hold the bowl bolt or main jet.
Of course always look for rub marks, where things were together.
Even "O"rings can leave imprints.

I"ll admit to coming from the clean it out or rebuild it crowd.
Just that the older, I get, the less fun it is to do so.
Thus my vote for getting new carb. ...hmm is my spirt that far gone

But I'm, still, somewhat prone to a cursory tear down of any new carb, just to check for oopsies.

 

[legdelimber]

I forgot to mention that sometimes you can look where stains were and find very slight surface etching on the mating parts, even after chemical cleaning.
Machined parts loose that sheen in the areas where it's been etched to the grain.
Ethanol and/or water tend to do rather well at leaving etched spots in our equipment.

Can often take some contorted fiddlings with the small flashlights and sometimes some patience
with a camera to see this though.

Metallurgists/inspectors may use staining agents to look for surface erosion or damage.
I expect that the gunsmithing crowd could school us rather well in this too!

 

[GMB74]

I believe the nozzle will fit in only one way. In your picture, the right hand end will go into the carb first, with the very end of the jet sticking up into the venturi area. If you try to put it in backwards it won't allow you to thread in the main jet to hold it in place.
Again, remarkably clean for its age.

 

[chipper1]

The guy I fixed it for uses non-ethanol fuel. The generator hadn't been run in 3 years. I cleaned the carb, put some fresh gas in it and it ran good. He used it for a weekend building a new tree stand in the woods and said it started to run goofy. Then he could not get it started. I found about a cup of water after draining the carb and tank. The fuel filter had enough water in it that it would not let the gas flow past it. I cleaned the carb again in a heated usc. Got the gen started and the rumble wouldn't clear up. The rumble is a weird flame in the cylinder.
A cheap amazon carb and fresh fuel, it runs like new.
So a 20 dollar carb, a 2 dollar filter and 10 minutes to change them wasn't the worst idea.

When you fuel a can at the gas station with multiple fuels on one hose, you can get up to a half gallon(depends on the hose length) of ethanol before starting to pump e free, if you're only buying a gallon or two at a time, you're not getting anywhere near e free. I buy all mine from an e free pump with its own designated tank, only one fuel comes out that hose.
Where would all that water come from if not from ethanol or some serious condensation.

 

[legdelimber]

By any chance did you take more photos of the carburetor before tear down?
Dosen't matter if they are a bit blurry or such. Just as long as you can tell what color the bits are, might be enough to spot a detail.
If you can see the brass protruding into the venturi, then sounds like GMB74 got ya sorted!

​

 

[WI_Hedgehog]

if a Honda carb lasts 20+ years without maintenance, and another 20 with mainenance, why waste time with aftermarket? Clean it, or if you have to put another OEM carb in. The last thing I want to do is replace an aftermarket carb every 3-5 years.