Congratulations, you own a fantastic mower, I love Honda and I know the Honda engineers love us too because it shows in the little details, plug wire holder, easy oil draining, gas bowl drain bolt.
Anyhow, all mowers suffer from a common complaint, clogged-up carburetor and Honda are no different. Surging is a common Honda issue and it commonly occurs because the carburetor idle jet is blocked.
Cleaning the jet usually fixes the issue, I say usually because sometimes the whole carburetor will need to be removed, stripped, and cleaned. Other common causes of a surging Honda include a bad spark plug, bad gas, moisture in the gas bowl, and blocked air filter, all these issues are easy to check and should be eliminated first before starting any carburetor work.
Faulty, worn-out carburetors, cracked carburetor manifold intakes, and leaking carburetor gaskets are common too. A damaged manifold and carb gasket will cause a vacuum leak, which results in an erratic idle (surging).
This video covers cleaning the idle jet and if that doesn’t work it also covers the removal, teardown, cleaning, and refitting of the carburetor. You’ll find other useful resources on this page, tips, links to tools, parts, and supplies required to complete your repair.
Before working on your mower be sure to remove the plug wire to prevent accidental starting, see “Repair Safety Video”.
Tools & Resources
Honda engines – Most take from empty .58 US quarts (.55 lts) of 10W30 engine oil.
For exact specs see:
To nail this procedure you may need some of the following tools, parts, and supplies.
This is first on the list for good reason, Wd solves a ton of problems. I won’t work without it, because I can’t. Picture links to Amazon.com.
Ratchet Tool Set
Before we can do anything, we’ll need tools. I’ve selected this set as I own some Craftsman tools and while I have worn some out, they did do a lot of work. So I expect this set will last the occasional user quite a long time. This set carries both metric and standard sockets and that’s important because some mowers will have both types of fastener sizes. Set includes spark plug sockets. Picture links to Amazon.com.
Gas & Oil Syphon
You’ll find this tool really useful if you need to drain the gas tank, and you will if the gas is stale. The siphon will remove it without fuss or mess and it can be used for extracting the oil too. Picture links to Amazon.com.
Gas Line Clamp
Some small engines will have a gas tap, which is really handy when removing the carburetor, stops gas flowing all over the shop. However most engines won’t have one, these useful clamps simply squeeze the fuel line and prevent a spill while you perform surgery. Picture links to Amazon.com.
When cleaning your carburetor you’ll need this stuff. Gumming is a sticky substance that’s hard to shift. The carb cleaner will remove it, however, if your carb is really bad, save yourself some work, go ahead and buy a new carburetor. Picture links to Amazon.com.
You’ll find these nylon brushes super useful when it comes time to clean those tiny passageways of the carburetor and jet. Use these in conjunction with the WD Carb cleaner. Picture links to Amazon.com.
Mix this with the gas when winterizing your small engine. Gas isn’t what it used to be, it goes stale, in some cases after just one month. Bad gas causes gumming and that’s a carburetor killer. A stabilizer will save you money and stress in the long run. Picture links to Amazon.com.
Briggs and Stratton refuel can. These guys got it right, I like it a lot, it offers press button control, no fuss no mess and no funnel required. Picture links to Amazon.com.
Every home needs a Dvom (Digital Volt Ohm Meter). It’s used to check for continuity in lawn mower wiring, and for voltage when there’s a battery fitted. But don’t use this tool to check spark, that will kill it. I use mine every day. I have the previous model to this and it’s still doing its job. Picture links to Amazon.com.
Now, this tool is a must-have if you’re removing the flywheel. Why would want to remove the flywheel? Sometimes the flywheel key shears, it stops your engine from starting. The key is really cheap and it’s easy to fix when you’ve got this tool. Picture links to Amazon.com.
Tap & Die Set
Used to cut threads. Many flywheels are not threaded which is a right pain in the jacksie, but this Gearwrench kit makes short work of threading. I especially like the ratcheting T handles. Picture links to Amazon.com.
This tool is used to check both the spark plug and the coil for spark. Sure you can check the spark without the tool, but it’s not as good, the tool is designed to stress the whole ignition system. Picture links to Amazon.com.
The ABN 26 blade feeler gauge set is marked in SAE and metric. You’ll need this set to adjust valve lash and is useful when setting armature/coil air gap. You can also use it to gap spark plugs. Picture links to Amazon.com.
Plug Gapper Tool
This tool isn’t strictly necessary if you have a feeler gauge, but it’s a lot easier to handle. If you haven’t guessed. You use this tool to check the gap of your spark plug, a simple effective tool. Picture links to Amazon.com.
This is a compression tester, it’s fitted in the plug hole using the adaptor. The gauge measures and captures the reading on the dial. A low reading can be caused by a simple fault such as a sticking valve. Picture links to Amazon.com.
The OTc is a quality kit and will last many years of use. A leak-down tester will require compressed air. The tester measures how much air escapes a cylinder and helps you find weak rings, valves head gaskets, etc. Picture links to Amazon.com.
I love DeWalt, they make quality tools. This heavy-duty but lightweight 1/2 inch impact wrench makes short work of stubborn bolts like flywheel nuts and rusty blade fasteners. Up to 700 ft-lbs of torque on tap, I keep one in the trunk of our family car, which makes a flat almost enjoyable. Picture links to Amazon.com.
I use a DeWalt screw gun (also a drill) in the workshop to speed up the process of removing engine covers, carburetor bolts, Armature bolts, etc. It’s a brushless motor and as tough as nails, I drove over it a few times – still works great! Batteries are interchangeable and so if you have a DeWalt product already you won’t need the battery. Picture links to Amazon.com.
Teng 1/2 Torque wrench, a fantastic tool I use it every day, and mine is still going strong. A torque wrench is advised for tightening components such as flywheel nuts and blades. The torque spec of these components is very important. Picture links to Amazon.com. If you’re buying a torque wrench, check out my review of Teng torque wrench, it’s the wrench I use.
Honda GCV 160
This is a Hooai carburetor fitted to the Honda GCV160 engine only, not the GVC190. It comes with gaskets, plugs, filters, and a fuel line. Fitting isn’t difficult, just a little tedious, take your time and some pictures of where the old gaskets are positioned and their orientation. Picture links to Amazon.com.
Honda GCV 190
This is a Hipa GCV 190 carburetor fitted to the Honda GCV190 engine only, not the GVC160. It comes with gaskets, plugs, filters, and a fuel line. Fitting isn’t difficult, just a little tedious, take your time and some pictures of where the old gaskets are positioned and their orientation. Picture links to Amazon.com.
Piston Stop Tool
Universal piston stop tool 10mm and 14mm, used to lock the crankshaft when removing and tightening the flywheel nut. Picture links to Amazon.com.
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John Cunningham is an Automotive Technician and writer at Lawnmowerfixed.com.
He’s been a mechanic for over twenty-five years and shares his know-how and hands-on experience in our DIY repair guides.
Johns’s fluff-free How-to guides help homeowners fix lawnmowers, tractor mowers, chainsaws, leaf blowers, power washers, generators, snow blowers, and more.