# Honda surging -- worth cleaning the carb, or replacing?



## Rudy (Jun 14, 2006)

I have three different Honda engines. The most recent is on an HRM215K1SXA mower, which I picked up cheap at an estate sale. 

Of course, the main problem is typical--surging at idle, and the engine runs partially choked. Starts on one or two pulls. I am thinking this is a typical case of someone leaving gasoline in the engine all winter long, or longer. I did try Seafoam but it did nothing, as expected.

Is it really worth working on the carbs on these, or just replacing? I don't do chinese parts or off-brand, so the official Honda carb lists for $42.99 on this mower. 16100-ZG9-M12.

I've read back about four years here on the forum, and the main thing is to make sure all of the orifices (jets) are cleaned out, making certain that varnish is gone. Do I need any special tools, and, can I do this without having to soak everything? I can use carb cleaner spray. Are there any sort of carb tools, like specific sized wire to clear out the jets? Or do we just wing it with whatever wire we have on hand (like the wire inside twist ties)? 

I have to attend to my older Honda mower (HR215SXA, circa 1990) and HS521 snowthrower (similar age), which aren't surging too badly as of yet, but the snowthrower does need choke partly on to run well. So, I don't want to be replacing three carbs instead of one, but if it's way too much bother with unsure results, I might just go that route, and resell the dirty carbs for someone else to mess with.


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## paulr44 (Oct 14, 2008)

I have a Honda jet cleaner that looks like (but isn't) a torch tip cleaner, it is quite expensive for the shade-tree mechanic.
You will need one special tool for working on most Japanese or Chinese carbs., and you can make it yourself. To remove the nozzle above the main jet, you need a screwdriver that has sides that don't bow out as most do (i.e. not wedge shaped). Just grind down the sides of one that the tip fits nicely in. You don't have much engagement with the nozzle slots, so fit is critical. B&S sold jet screwdrivers years ago, but we've found that a RedMax screwdriver that comes with equipment (many motorcycles came with one too) that has a reversible insert (spade one end, Phillips the other) actually works quite well. Sometimes the least expensive or homemade works better than tool-truck bought.

As for cleaning the jets, two things come into play. If you have good solvents, such as a spray containing xylene (nasty stuff, works well, use in ventilated area) or a good ultrasonic cleaner, you should be ok. TWIST ties wires are typically too weak.
What I use for cleaning some jets, and you shouldn't need to unless there's gum/varnish you can't eradicate, I made my own for just such occasions. I take a 7" or so old piece of throttle control wire, straighten it out fairly well, put an L bend at one end as a handle, and carefully grind the other end with a long taper, on 4 sides making it squared. You have to go very lightly near the tip to bring it to a sharp point, and it being a gradual taper is important. When you put it in the jet, lightly turn it and the flat sides of the square shank act like little lathe bits and scrape the crap out. If you use excessive force, you'll either enlarge the jet (making it run too rich) or put gouges in the jet which can potentially catch air bubbles and cause a restriction resulting in a lean condition.

Aside from cleaning the jets and nozzles, spray carb. cleaner from the top of them down through the pilot system. Most of them have needles you can't remove without breaking, and replacement screws are like $20+.

Honestly though, for $42 a piece for an OEM carb. I'd just throw new ones one. I spent $40 a piece for 2 OEM inlet needles for a Yamaha bike I owned 10 yrs. ago, and had a hard time justifying it considering the quality of some of the aftermarket kits out there. Obviously you get what you pay for, but you have to be the judge of that.


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## Rudy (Jun 14, 2006)

Hello Paul, thank you for the feedback.

I agree it's a point of diminishing returns--the time involved, the cost and time to buy or fabricate tools, etc. can make it impractical.

In an ultrasonic cleaner, what type of detergent or solvent would you use? I have one, but it is rather large (holds almost two gallons).

I wonder if a bamboo skewer would be a good tool--it's a little stronger than wood, but softer than the metals in the carb. It's easily "machined" down to a specific size, but might be too impractical if it gets really thin.

For my older engines, though, I may not have a choice, as the carbs were discontinued, superseded, then discontinued again, etc. At least I have the luxury of time on these two--the snowthrower I hopefully won't need until the end of the year, and the old mower will likely just be stored, or used occasionally over the summer.


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## John Lolli (Nov 3, 2005)

I have had pretty good success cleaning Honda Carbs. I have an ultrasonic cleaner from Harbor Freight that has served me well. I use a mixture of Simple Green, Dawn Liquid Dish Detergent and water. I use the heat feature as well. I typically cycle the unit through three cleanings. Honda carbs are tricky, you have to get the emulsion tube out as well as the jet. I use the very thin hinge connector from a needle / seat kit to clean the holes in the emulsion tube.


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## paulr44 (Oct 14, 2008)

Simple green, yes. And heat, yes. About 110 to 120 deg. seems to be good. There are powders etc. you can buy specifically for aluminum, but not all carbs. are aluminum, some are "pot" metal, or what we used to call "white' metal, and some of the cleansers turn the metal dark, while the Simple G. leaves it shiny.

It's rare that I've ever had to poke the nozzle feed holes out, usually a good soak and/or carb. spray cleans 'em up.
And as for the "reaming" the jets, again, only if there's recalcitrant gum/varnish. For what jets cost on Walbro carbs., I just replace them with guaranteed results...don't want to have to open up a carb. a second time, that's not profitable.

The most common GX160 carb. (OEM) costs between $30 and $40, so for me to rebuild/clean one it doesn't make sense. It'd cost the customer about the same or more to clean/rebuild, than to replace. Especially if you factor in a carb. gasket kit, inlet needle and the $20+ idle mixture screw. The GC/GCV carbs. (OEM) are less than $30 typically, some close to $20...a real no-brainer.

As a footnote, if the surging or idle isn't that bad yet still not right, you could try removing the pilot jet from on top of the carbs. and spray carb. cleaner down the tube.


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