Got a sweet deal today— I think….

[Krfjkm]

Over coffee this morning a glanced at the FB Markrtplace and saw a 6500 watt generator with a 13 HP Honda engine for $50.

They said it had been stored for 2 years and wouldn’t start. I checked to be sure the compression was good and checked the hour gauge (1400) and loaded it up.

I’m thinking a new carb and a thorough fuel system cleaning and I should be good to go.

Here’s my question—- there are a lot of carbs for the Honda GX 390 but one I was about to order said “not for use on a generator”

Would you guys know why it would say that?

Thanks!

 

[PCustoms]

Here’s my question—- there are a lot of carbs for the Honda GX 390 but one I was about to order said “not for use on a generator”

Would you guys know why it would say that?

Thanks!

Off the cuff (I don't know really), are generators compatible with auto choke carbs?

@Metallitubby is the resident Honda guru, he should know the realm answer

 

[WildBill]

In my experience generator carbs aren't setup for a throttle cable, they are controlled some other way. Last one I did I took the throttle linkage stuff off the old carb and swapped it to the new one. But you probably want to find one for a generator, they are usually not hard to find. Or really look at the pics of the new carb to make sure you can connect the linkage.

 

[aquinob]

There are a lot of chinese made carbs on the market for just about any power equipment. Some are fine, some maybe not so fine.

Before you go just replacing it, you can try a thorough cleaning. Ethanol is murder on carbs if it's left to sit. If you have an ultrasonic cleaner that would be the way to go, although you can do a decent job with just carb cleaner and some careful cleaning. I would also check for a spark and make sure the fuel pump is working if it has one. Good Luck.

 

[Fixr]

There are a lot of chinese made carbs on the market for just about any power equipment. Some are fine, some maybe not so fine.

Before you go just replacing it, you can try a thorough cleaning. Ethanol is murder on carbs if it's left to sit. If you have an ultrasonic cleaner that would be the way to go, although you can do a decent job with just carb cleaner and some careful cleaning. I would also check for a spark and make sure the fuel pump is working if it has one. Good Luck.

And if he doesn't have an ultrasonic cleaner, at $50 for the generator he can afford to buy one and a gallon of Pine Sol

 

[finn]

Don’t know about those homeowner gas generators, but the Governor on a commercial generator would be set up with tighter regulation, to the point of being more or less isochronous, compared to the same engine in a typical industrial application.

 

[Fixr]

Don’t know about those homeowner gas generators, but the Governor on a commercial generator would be set up with tighter regulation, to the point of being more or less isochronous, compared to the same engine in a typical industrial application.

Admit it. You just wanted to use the word isochronous.

 

[Krfjkm]

And if he doesn't have an ultrasonic cleaner, at $50 for the generator he can afford to buy one and a gallon of Pine Sol

Yep, I got a nice ultrasonic cleaner!

 

[Krfjkm]

Not sure if it is isochronous— I’ll check the manual…

 

[klutchdust]

After replacing some carburetors on my Honda stuff I was wandering around the big orange store and saw something interesting. It's called "mechanic in a bottle" I chuckled but started reading the information on the side. Add some to the fuel tank of a poor running engine( with clean fuel) add a lot to a non running / won't start engine. It works. it cleans that varnish off the carb parts and gets stuff going again. Out here in Ca. it's getting harder to find. Last purchase was online. I have had poor results with sta-bil. Not sure why.
For my Stihl saw I use premixed 40 to 1 by the gallon, pricy but keeps my rotator cuff in working order. After sitting for a few months the saw starts with 2 pulls.

 

[The Cobbler]

I would try cleaning it first. a clone carb is no comparison to an OEM Honda
the not for generators wouldn't bother me too much . generators don't idle so the carbs may be slightly different, but would very likely be adaptable & work . again, replacement would be low on my list, even tho I
m pro generic carbs if you can't clean up the oem .

Oh, and BTW, a nice grab.

 

[Krfjkm]

Thanks for all the thoughts and suggestions. I think I am going to drop it in my ultrasonic and proceed from there. First step is to drain and clean the tank. Any suggestions for cleaning a plastic tank?

 

[The Cobbler]

pinesol for an hour undiluted , mix it around every so often so all surfaces get covered. remove the in tank filter at the gas outlet and see how it is.
rinse well and dry well

 

[drmarkr]

Thanks for all the thoughts and suggestions. I think I am going to drop it in my ultrasonic and proceed from there. First step is to drain and clean the tank. Any suggestions for cleaning a plastic tank?

If the low speed jet is removable, that is by far the most common issue....remove and clean with a small wire if compressed air won't clean it out.

 

[hobie18]

Emulsion tube too. There may be a filter at the tank.

 

[tooljunkie4]

Also, copper-coated BBs. Toss a heavy handful into the tank with your solvent, close it up, and shake well. If there is any sort of mess attached to the inside of the tank, that should knock it off without blowing you up.

 

[hobie18]

You should be able to use a plastic bag inside the ultrasonic tank. Keeps the tool clean. Make sure there is liquid in both. Plain should work outside the bah.

 

[finn]

Admit it. You just wanted to use the word isochronous.

Pretty common terminology in the technical world among those that have ever developed power plants for generator applications, combines, etc. Really, any application that requires a steep governor regulation curves to maintain constant engine speed under load.

This isn’t a very technical audience here on garage journal, I keep forgetting, though.

 

[Fixr]

Pretty common terminology in the technical world among those that have ever developed power plants for generator applications, combines, etc. Really, any application that requires a steep governor regulation curves to maintain constant engine speed under load.

This isn’t a very technical audience here on garage journal, I keep forgetting, though.

I think we got quite a few technical people here, but they are in a whole lot of different fields and terminology doesn't always overlap much.

 

[75gmck25]

I have a Toro mower that started running rough and I figured it was the carburetor. Found some replacements online, but it's a very simple carburetor so I decided to just take a look at it first. I have multiple tools I used when rebuilding my Quadrajet, but found that most were serious overkill for this simple carburetor.

Took everything apart that I could, and used a pin vise and ultra small drill bits to gently clean out every orifice. Soaked it in water/Dawn solution for a while, rinsed it really well, and blew through everything with compressed air. Reinstalled it with a new filter and everything worked liked new.

 

[Jswain]

I would go the even faster route and just drain the gas in the tank if it is full(if it's low enough just fill it with premium), remove drain screw on carb bowl, flush a little fuel through it then put it back in. This will fix most and it's 5 minutes of work.

If the fuel doesn't keep flowing out of the drain after the bowl is empty tap on the bowl or remove, the float is likely stuck shut.

 

[Metallitubby]

Off the cuff (I don't know really), are generators compatible with auto choke carbs?

Yes. Usually, the reason engines are not compatible for generator usage is thrust-washer specification and auto-throttle (if equipped).

 

[Metallitubby]

Here’s my question—- there are a lot of carbs for the Honda GX 390 but one I was about to order said “not for use on a generator”

Use the serial number of the engine (NOT the model number) and enter it on Jack's Small Engines' website, and buy the correct carburetor. I personally, would clean the carburetor for free in about ten minutes, but it's your money/time.

 

[PoorUB]

Thanks for all the thoughts and suggestions. I think I am going to drop it in my ultrasonic and proceed from there. First step is to drain and clean the tank. Any suggestions for cleaning a plastic tank?

Try clean the carb. It might just be gunk in the bottom of the bowl. Once in a while a guy gets lucky!

Clean a gas tank? Pressure washer! Blast out what you can. One thing nice about plastic is stuff doesn't stick to it very well so you should be able to get most of it.

 

[Bill T]

Not sure if it is isochronous— I’ll check the manual…

It reminds me.... in my wasted youth (1960's), there was a "head" shop in Charlotte- the "Chronosynclasticisoinfidibulum". Off topic, but I have always wanted to use this word too

 

[john.k]

Common fault with Honda generators was flooding carb ...needle and seat was over $100 ,and many just set the genset aside .

 

[Metallitubby]

Try clean the carb. It might just be gunk in the bottom of the bowl.

It's almost always the main and/or transfer/pilots on our stuff.

 

[Steve.S]

Fixed it for ya!

Not sure if it is isochronous— I’ll check the manual dictionary…

 

[CraigStu]

When you buy gas get non ethanol if you can.

 

[theoldwizard1]

I’m thinking a new carb and a thorough fuel system cleaning and I should be good to go.

A REAL GJ'er would remove the carb, disassemble it, put it in a pot of water with a generous amount of Dawn dishwashing liquid and simmer it on the stove for about 30 minutes. (After market carburetors are a "shot in the dark". Some work, most DO NOT !)

Finally, take a piece of fine stiff wire (single strand from a wire brush) and run it through every small opening. Watch a couple of James Condon's videos on YouTube.

 

[theoldwizard1]

In my experience generator carbs aren't setup for a throttle cable, they are controlled some other way.

Unless it is an inverter generator or has some kind of "no load, throttle down" mechanism, generators are designed to run wide open ! Their speed is controlled by the governor.

 

[theoldwizard1]

Not certain about the carb on the GX390, but if it is like other Honda (and Honda clone) carburetors they are dumb, stupid, simple !

Remove the bottom bowl nut and then the bowl. Be careful with the "O-ring" that seals the bowl to the carburetor body. Some petroleum based cleaners will cause it to swell, so just leave it in place. Make sure any orifices in the bowl nut are clear.

The tube running up the middle (that the bowl nut screws into) holds the main/secondary/high speed jet and the emulation tube. A special screw driver is require to remove the jet ! It is important to remove it an check to see if is clear. The emulation tube needs to be removed (tapping the carburetor should get it to fall out) and checked to be sure all opening are clear.

What appears to be the idle set screw holds the pilot/primary/low speed jet in place. Remove the screw and gently pry out the jet (plastic around brass).